<PAGE>   1

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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                            ------------------------

                                   FORM 10-Q
                            ------------------------

      [X]   QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
            EXCHANGE ACT OF 1934

               FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 1999

                                       OR

      [ ]   TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
            EXCHANGE ACT OF 1934

         FOR THE TRANSITION PERIOD FROM ____________ TO ____________ .

                         COMMISSION FILE NUMBER 0-21518

                            ------------------------

                           IEA INCOME FUND XII, L.P.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

<TABLE>
<S>                                            <C>
                  CALIFORNIA                                     94-3143940
       (STATE OR OTHER JURISDICTION OF                        (I.R.S. EMPLOYER
        INCORPORATION OR ORGANIZATION)                      IDENTIFICATION NO.)

        444 MARKET STREET, 15TH FLOOR,
          SAN FRANCISCO, CALIFORNIA                                94111
   (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)                      (ZIP CODE)
</TABLE>

                                 (415) 677-8990
              (REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE)

                            ------------------------

     Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports), and (2) has been subject to such
filing requirements for the past 90 days.  Yes [X]  No [ ]

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<PAGE>   2

                           IEA INCOME FUND XII, L.P.

                  REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD
                            ENDED SEPTEMBER 30, 1999

                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                       PAGE
                                                                       ----
<S>      <C>                                                           <C>
PART I -- FINANCIAL INFORMATION
Item 1.  Financial Statements
         Balance Sheets -- September 30, 1999 (unaudited) and
         December 31, 1998...........................................    4
         Statements of Operations for the three and nine months ended
         September 30, 1999 and 1998 (unaudited).....................    5
         Statements of Cash Flows for the nine months ended September
         30, 1999 and 1998 (unaudited)...............................    6
         Notes to Financial Statements (unaudited)...................    7
Item 2.  Management's Discussion and Analysis of Financial Condition
         and Results of Operations...................................   10
Item 3.  Quantitative and Qualitative Disclosures About Market
         Risk........................................................   12

PART II -- OTHER INFORMATION
Item 1.  Legal Proceedings...........................................   13
Item 3.  Defaults Upon Senior Securities.............................   13
Item 5.  Other Information...........................................   13
Item 6.  Exhibits and Reports on Form 8-K............................   14
</TABLE>

                                        2
<PAGE>   3

                        PART I -- FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

Presented herein are the Registrant's balance sheets as of September 30, 1999
and December 31, 1998, statements of operations for the three and nine months
ended September 30, 1999 and 1998, and statements of cash flows for the nine
months ended September 30, 1999 and 1998.

                                        3
<PAGE>   4

                           IEA INCOME FUND XII, L.P.

                                 BALANCE SHEETS
                                  (UNAUDITED)


<TABLE>
<CAPTION>
                                                              SEPTEMBER 30,    DECEMBER 31,
                                                                  1999             1998
                                                              -------------    ------------
<S>                                                           <C>              <C>
                                        ASSETS

Current assets:
  Cash and cash equivalents, includes $1,868,389 at September
     30, 1999 and $2,407,514 at December 31, 1998 in
     interest-bearing accounts..............................   $ 1,868,489     $ 2,407,614
  Net lease receivables due from Leasing Company (notes 1
     and 2).................................................       183,124         656,520
                                                               -----------     -----------
          Total current assets..............................     2,051,613       3,064,134
                                                               -----------     -----------
Container rental equipment, at cost.........................    62,003,870      62,646,590
  Less accumulated depreciation.............................    25,401,439      23,010,870
                                                               -----------     -----------
     Net container rental equipment.........................    36,602,431      39,635,720
                                                               -----------     -----------
                                                               $38,654,044     $42,699,854
                                                               ===========     ===========

                             LIABILITIES AND PARTNERS' CAPITAL
Current liabilities:
  Accrued expenses..........................................   $   416,624     $   462,948
                                                               -----------     -----------
          Total current liabilities.........................       416,624         462,948
                                                               -----------     -----------
Partners' capital (deficit):
  General partner...........................................      (104,892)        (64,897)
  Limited partners..........................................    38,342,312      42,301,803
                                                               -----------     -----------
          Total partners' capital...........................    38,237,420      42,236,906
                                                               -----------     -----------
                                                               $38,654,044     $42,699,854
                                                               ===========     ===========
</TABLE>

   The accompanying notes are an integral part of these financial statements.
                                        4
<PAGE>   5

                           IEA INCOME FUND XII, L.P.

                            STATEMENTS OF OPERATIONS
                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                    THREE MONTHS ENDED               NINE MONTHS ENDED
                                               -----------------------------   -----------------------------
                                               SEPTEMBER 30,   SEPTEMBER 30,   SEPTEMBER 30,   SEPTEMBER 30,
                                                   1999            1998            1999            1998
                                               -------------   -------------   -------------   -------------
<S>                                            <C>             <C>             <C>             <C>
Net lease revenue (notes 1 and 3)............    $ 882,030      $1,252,615      $2,782,635      $4,033,477
Other operating expenses:
  Depreciation...............................      911,896         916,386       2,743,388       2,758,518
  Other general and administrative
     expenses................................       27,205          30,805          84,935          82,293
                                                 ---------      ----------      ----------      ----------
                                                   939,101         947,191       2,828,323       2,840,811
                                                 ---------      ----------      ----------      ----------
     Earnings (loss) from operations.........      (57,071)        305,424         (45,688)      1,192,666
Other income (loss):
  Interest income............................       22,389          30,802          69,963          88,496
  Net loss on disposal of equipment..........      (74,144)        (17,816)       (152,768)        (21,058)
                                                 ---------      ----------      ----------      ----------
                                                   (51,755)         12,986         (82,805)         67,438
                                                 ---------      ----------      ----------      ----------
     Net earnings (loss).....................    $(108,826)     $  318,410      $ (128,493)     $1,260,104
                                                 =========      ==========      ==========      ==========
Allocation of net earnings (loss):
  General partner............................    $  45,761      $   56,813      $  141,727      $  173,488
  Limited partners...........................     (154,587)        261,597        (270,220)      1,086,616
                                                 ---------      ----------      ----------      ----------
                                                 $(108,826)     $  318,410      $ (128,493)     $1,260,104
                                                 =========      ==========      ==========      ==========
Limited partners' per unit share of net
  earnings (loss)............................    $   (0.05)     $     0.08      $    (0.08)     $     0.31
                                                 =========      ==========      ==========      ==========
</TABLE>

   The accompanying notes are an integral part of these financial statements.
                                        5
<PAGE>   6

                           IEA INCOME FUND XII, L.P.

                            STATEMENTS OF CASH FLOWS
                                  (UNAUDITED)

<TABLE>
<CAPTION>
                                                                    NINE MONTHS ENDED
                                                              ------------------------------
                                                              SEPTEMBER 30,    SEPTEMBER 30,
                                                                  1999             1998
                                                              -------------    -------------
<S>                                                           <C>              <C>
Net cash provided by operating activities...................   $ 3,079,090      $ 4,008,452
Cash flows provided by (used in) investing activities:
  Proceeds from disposal of equipment.......................       462,087          385,590
  Purchase of container rental equipment....................      (199,342)              --
  Acquisition fees paid to general partner..................        (9,967)              --
                                                               -----------      -----------
     Net cash provided by investing activities..............       252,778          385,590
                                                               -----------      -----------
Cash flows used in financing activities:
  Distribution to partners..................................    (3,870,993)      (4,022,139)
                                                               -----------      -----------
Net increase (decrease) in cash and cash equivalents........      (539,125)         371,903
Cash and cash equivalents at January 1......................     2,407,614        1,883,389
                                                               -----------      -----------
Cash and cash equivalents at September 30...................   $ 1,868,489      $ 2,255,292
                                                               ===========      ===========
</TABLE>

   The accompanying notes are an integral part of these financial statements.
                                        6
<PAGE>   7

                           IEA INCOME FUND XII, L.P.

                    NOTES TO UNAUDITED FINANCIAL STATEMENTS

(1) SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

     (a) Nature of Operations

     IEA Income Fund XII, L.P. (the "Partnership") is a limited partnership
organized under the laws of the State of California on August 28, 1991 for the
purpose of owning and leasing marine cargo containers. Cronos Capital Corp.
("CCC") is the general partner and, with its affiliate Cronos Containers Limited
(the"Leasing Company"), manages the business of the Partnership. The Partnership
shall continue until December 31, 2011, unless sooner terminated upon the
occurrence of certain events.

     The Partnership commenced operations on January 31, 1992, when the minimum
subscription proceeds of $2,000,000 were obtained. The Partnership offered
3,750,000 units of limited partnership interest at $20 per unit, or $75,000,000.
The offering terminated on November 30, 1992, at which time 3,513,594 limited
partnership units had been purchased.

     (b) Leasing Company and Leasing Agent Agreement

     The Partnership has entered into a Leasing Agent Agreement whereby the
Leasing Company has the responsibility to manage the leasing operations of all
equipment owned by the Partnership. Pursuant to the Agreement, the Leasing
Company is responsible for leasing, managing and re-leasing the Partnership's
containers to ocean carriers and has full discretion over which ocean carriers
and suppliers of goods and services it may deal with. The Leasing Agent
Agreement permits the Leasing Company to use the containers owned by the
Partnership, together with other containers owned or managed by the Leasing
Company and its affiliates, as part of a single fleet operated without regard to
ownership. Since the Leasing Agent Agreement meets the definition of an
operating lease in Statement of Financial Accounting Standards (SFAS) No. 13, it
is accounted for as a lease under which the Partnership is lessor and the
Leasing Company is lessee.

     The Leasing Agent Agreement generally provides that the Leasing Company
will make payments to the Partnership based upon rentals collected from ocean
carriers after deducting direct operating expenses and management fees to CCC
and the Leasing Company. The Leasing Company leases containers to ocean
carriers, generally under operating leases which are either master leases or
term leases (mostly two to five years). Master leases do not specify the exact
number of containers to be leased or the term that each container will remain on
hire but allow the ocean carrier to pick up and drop off containers at various
locations; rentals are based upon the number of containers used and the
applicable per-diem rate. Accordingly, rentals under master leases are all
variable and contingent upon the number of containers used. Most containers are
leased to ocean carriers under master leases; leasing agreements with fixed
payment terms are not material to the financial statements. Since there are no
material minimum lease rentals, no disclosure of minimum lease rentals is
provided in these financial statements.

     (c) Basis of Accounting

     The Partnership utilizes the accrual method of accounting. Net lease
revenue is recorded by the Partnership in each period based upon its leasing
agent agreement with the Leasing Company. Net lease revenue is generally
dependent upon operating lease rentals from operating lease agreements between
the Leasing Company and its various lessees, less direct operating expenses and
management fees due in respect of the containers specified in each operating
lease agreement.

     (d) Financial Statement Presentation

     These financial statements have been prepared without audit. Certain
information and footnote disclosures normally included in financial statements
prepared in accordance with generally accepted accounting procedures have been
omitted. It is suggested that these financial statements be read in conjunction
with the financial statements and accompanying notes in the Partnership's latest
annual report on Form 10-K.

                                        7
<PAGE>   8
                           IEA INCOME FUND XII, L.P.

              NOTES TO UNAUDITED FINANCIAL STATEMENTS (CONTINUED)

     The preparation of financial statements in conformity with generally
accepted accounting principles (GAAP) requires the Partnership to make estimates
and assumptions that affect the reported amounts of assets and liabilities and
disclosure of contingent assets and liabilities at the date of the financial
statements and the reported amounts of revenues and expenses during the reported
period. Actual results could differ from those estimates.

     The interim financial statements presented herewith reflect all adjustments
of a normal recurring nature which are, in the opinion of management, necessary
to a fair statement of the financial condition and results of operations for the
interim periods presented.

(2) NET LEASE RECEIVABLES DUE FROM LEASING COMPANY

     Net lease receivables due from the Leasing Company are determined by
deducting direct operating payables and accrued expenses, base management fees
payable, and reimbursed administrative expenses payable to CCC and its
affiliates from the rental billings payable by the Leasing Company to the
Partnership under operating leases to ocean carriers for the containers owned by
the Partnership. Net lease receivables at September 30, 1999 and December 31,
1998 were as follows:

<TABLE>
<CAPTION>
                                                             SEPTEMBER 30,    DECEMBER 31,
                                                                 1999             1998
                                                             -------------    ------------
<S>                                                          <C>              <C>
Lease receivables, net of doubtful accounts of $194,100 at
  September 30, 1999 and $209,635 at December 31, 1998.....   $1,406,931       $1,690,827
Less:
Direct operating payables and accrued expenses.............      723,619          491,270
Damage protection reserve..................................      223,070          237,855
Base management fees.......................................      245,537          271,288
Reimbursed administrative expenses.........................       31,581           33,894
                                                              ----------       ----------
                                                              $  183,124       $  656,520
                                                              ==========       ==========
</TABLE>

(3) NET LEASE REVENUE

     Net lease revenue is determined by deducting direct operating expenses,
base management fees and reimbursed administrative expenses to CCC and its
affiliates from the rental revenue billed by the Leasing Company under operating
leases to ocean carriers for the containers owned by the Partnership. Net lease
revenue for the three and nine-month periods ended September 30, 1999 and 1998
was as follows:

<TABLE>
<CAPTION>
                                               THREE MONTHS ENDED                NINE MONTHS ENDED
                                         ------------------------------    ------------------------------
                                         SEPTEMBER 30,    SEPTEMBER 30,    SEPTEMBER 30,    SEPTEMBER 30,
                                             1999             1998             1999             1998
                                         -------------    -------------    -------------    -------------
<S>                                      <C>              <C>              <C>              <C>
Rental revenue (note 4)................   $1,596,370       $2,183,010       $5,065,891       $6,500,276
Less:
Rental equipment operating expenses....      513,911          646,410        1,637,155        1,624,038
Base management fees...................      110,284          147,356          349,252          441,948
Reimbursed administrative expenses.....       90,145          136,629          296,849          400,813
                                          ----------       ----------       ----------       ----------
                                          $  882,030       $1,252,615       $2,782,635       $4,033,477
                                          ==========       ==========       ==========       ==========
</TABLE>

(4) OPERATING SEGMENT

     The Financial Accounting Standards Board has issued SFAS No. 131,
"Disclosures about Segments of an Enterprise and Related Information," which
changes the way public business enterprises report financial and descriptive
information about reportable operating segments. An operating segment is a
component of an

                                        8
<PAGE>   9
                           IEA INCOME FUND XII, L.P.

              NOTES TO UNAUDITED FINANCIAL STATEMENTS (CONTINUED)

enterprise that engages in business activities from which it may earn revenues
and incur expenses, whose operating results are regularly reviewed by the
enterprise's chief operating decision maker to make decisions about resources to
be allocated to the segment and assess its performance, and about which separate
financial information is available. Management operates the Partnership's
container fleet as a homogenous unit and has determined, after considering the
requirements of SFAS No. 131, that as such it has a single reportable operating
segment.

     The Partnership derives its revenues from owning and leasing marine cargo
containers. As of September 30, 1999, the Partnership operated 9,245
twenty-foot, 5,180 forty-foot and 205 forty-foot high-cube marine dry cargo
containers, as well as 195 twenty-foot and 297 forty-foot marine refrigerated
cargo containers. A summary of gross lease revenue, by product, for the three
and nine-month periods ended September 30, 1999 and 1998 was as follows:

<TABLE>
<CAPTION>
                                               THREE MONTHS ENDED                NINE MONTHS ENDED
                                         ------------------------------    ------------------------------
                                         SEPTEMBER 30,    SEPTEMBER 30,    SEPTEMBER 30,    SEPTEMBER 30,
                                             1999             1998             1999             1998
                                         -------------    -------------    -------------    -------------
<S>                                      <C>              <C>              <C>              <C>
Dry cargo containers...................   $1,345,079       $1,790,566       $4,150,524       $5,277,799
Refrigerated containers................      251,291          392,444          915,367        1,222,477
                                          ----------       ----------       ----------       ----------
          Total........................   $1,596,370       $2,183,010       $5,065,891       $6,500,276
                                          ==========       ==========       ==========       ==========
</TABLE>

     Due to the Partnership's lack of information regarding the physical
location of its fleet of containers when on lease in the global shipping trade,
it is impracticable to provide the geographic area information required by SFAS
No. 131. Any attempt to separate "foreign" operations from "domestic" operations
would be dependent on definitions and assumptions that are so subjective as to
render the information meaningless and potentially misleading.

                                        9
<PAGE>   10

ITEM 2. MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS
OF OPERATIONS

     It is suggested that the following discussion be read in conjunction with
the Registrant's most recent annual report on Form 10-K.

     (1) Material changes in financial condition between September 30, 1999 and
December 31, 1998.

     At September 30, 1999, the Registrant had $1,868,489 in cash and cash
equivalents, a decrease of $539,125 from the December 31, 1998 cash balances.

     The Registrant's operating performance contributed to a 72% decline in net
lease receivables at September 30, 1999 when compared to December 31, 1998. The
Registrant's cash distribution from operations for the third quarter of 1999 was
5.75% (annualized) of the limited partners' original capital contributions, a
decline from the second quarter of 1999 distribution of 6.00% (annualized).
These distributions are directly related to the Registrant's results from
operations and may fluctuate accordingly.

     As discussed in previous quarters, improving prospects in the Asia-Pacific
region have been the impetus for a recovery in containerized trade volumes.
Strong demand in North America has generated increases in transpacific volumes
from Asia, and imports into Asia are also improving as a result of economic
recovery in the region. As a result, container lease-outs from both North
America and Europe are showing signs of revival.

     The General Partner previously reported that trade imbalances, which were
heightened by the Asian financial crisis, resulted in the necessity to
reposition off-hire equipment from low-demand drop-off locations in North
America and Europe to higher-demand areas in Asia. Such imbalances continue to
be widespread in the container leasing industry. In order to meet the stronger
demand in Asia, the General Partner will continue to reposition the Registrant's
idle equipment as warranted by market conditions. This repositioning will allow
us to better fulfill customer requirements, while at the same time reducing
costs associated with handling and storing off-hire or stockpiled equipment.

     (2) Material changes in the results of operations between the three and
nine-month periods ended September 30, 1999 and the three and nine-month periods
ended September 30, 1998.

     Net lease revenue for the three and nine-month periods ended September 30,
1999 was $882,030 and $2,782,635, respectively, a decrease of 30% and 31%
respectively, from the same periods in the prior year. Gross rental revenue (a
component of net lease revenue) for the three and nine-month periods ended
September 30, 1999 was $1,596,370 and $5,065,891, respectively, reflecting a
decline of 27% and 22%, respectively, from the same periods in the prior year.
Gross lease revenue was primarily impacted by lower per-diem rental rates and
utilization levels. Average dry cargo container per-diem rental rates for the
three and nine-month periods ended September 30, 1999 declined approximately 13%
and 8%, respectively, when compared to the same periods in the prior year.
Refrigerated container average per-diem rental rates for the three and
nine-month periods ended September 30, 1999 declined 19% and 12%, respectively,
when compared to the same periods in the prior year.

     The Registrant's average fleet size and utilization rates for the three and
nine-month periods ended September 30, 1999 and 1998 were as follows:

<TABLE>
<CAPTION>
                                                    THREE MONTHS ENDED               NINE MONTHS ENDED
                                               -----------------------------   -----------------------------
                                               SEPTEMBER 30,   SEPTEMBER 30,   SEPTEMBER 30,   SEPTEMBER 30,
                                                   1999            1998            1999            1998
                                               -------------   -------------   -------------   -------------
<S>                                            <C>             <C>             <C>             <C>
Average fleet size (measured in twenty-foot
  equivalent units (TEU))
  Dry cargo containers.......................     20,038          20,189          20,090          20,361
  Refrigerated containers....................        797             808             802             808
Average Utilization
  Dry cargo containers.......................         71%             75%             68%             82%
  Refrigerated containers....................         64%             77%             67%             84%
</TABLE>

                                       10
<PAGE>   11

     Rental equipment operating expenses were 32% of the Registrant's gross
lease revenue during both the three and nine-month periods ended September 30,
1999, as compared to 30% and 25%, respectively, of the Registrant's gross lease
revenue during the three and nine-month periods ended September 30, 1998. This
increase was largely attributable to an increase in costs associated with
slightly lower utilization levels, including handling and storage.

     The Registrant disposed of 23 twenty-foot and 12 forty-foot marine dry
cargo containers as well as eight forty-foot marine refrigerated cargo
containers during the third quarter of 1999, as compared to 14 twenty-foot, 13
forty-foot, and one forty-foot high-cube marine dry cargo containers during the
same period in the prior year. The decision to repair or dispose of a container
is made when it is returned by a lessee. This decision is influenced by various
factors including the age, condition, suitability for continued leasing, as well
as the geographical location of the container when disposed. These factors also
influence the amount of sales proceeds received and the related gain on
container disposals.

YEAR 2000

     The Registrant relies upon the financial and operational systems provided
by the Leasing Company and its affiliates, as well as the systems provided by
other independent third parties to service the three primary areas of its
business: investor processing/maintenance; container leasing/asset tracking; and
accounting finance. The Leasing Company's computer systems have undergone
modifications in order to render the systems ready for the Year 2000. The
Leasing Company has completed a detailed inventory of all software and hardware
systems and has identified all components that need to be modified. The Leasing
Company has completed all the necessary changes and testing in a dedicated Year
2000 environment. All compliant code was made live in August 1999. The Leasing
Company has contacted all of its critical business suppliers and has been
advised that their systems are Year 2000 compliant. The Leasing Company has also
confirmed the compliance of its suppliers' products through its own extensive
testing. Expenses associated with addressing Year 2000 issues are being
recognized as incurred. Management has not yet assessed the Year 2000 compliance
expense but does not anticipate the costs incurred to date or to be incurred in
the future by the Leasing Company and its affiliates to be in excess of
$500,000. None of the costs incurred with respect to Year 2000 compliance will
be borne by the Registrant. The Leasing Company believes it will be able to
resolve any major Year 2000 issues. The Leasing Company is aware of the
implications of a Year 2000 computer system failure and is currently in the
process of developing its contingency plans. While management believes the
possibility of a Year 2000 system failure to be remote, if the Leasing Company's
internal systems or those of its critical business suppliers fail, the Leasing
Company's consolidated financial position, liquidity or results of operations
may be adversely affected.

CAUTIONARY STATEMENT

     This Quarterly Report on Form 10-Q contains statements relating to future
results of the Registrant including certain projections and business trends,
that are "forward-looking statements" as defined in the Private Securities
Litigation Reform Act of 1995, including, without limitation, (a) the statements
in Management's Discussion and Analysis of Financial Condition and Results of
Operations concerning (i) preliminary indications that trade volumes from North
America and Europe to Asia may be increasing (ii) the Leasing Company's
expectation that its repositioning strategy will place container equipment in
higher demand locations and that it will improve utilization; (b) the statements
under Year 2000 concerning (i) the Leasing Company's belief that it will be able
to resolve any major year 2000 issues (ii) the Leasing Company's belief that the
possibility of a year 2000 failure is remote; and (c) the statements under Legal
Proceedings concerning the Parent Company's hope of settling the SEC
investigation by the end of 1999.

     Forward-looking statements are based upon management's current expectations
and beliefs concerning future developments and their potential effects upon the
Registrant. There can be no assurance that future developments will be in
accordance with management's expectations or that the effect of future
developments on the Registrant will be those anticipated by management. Actual
results may differ materially from those projected as a result of certain risks
and uncertainties, including, but not limited to, changes in: economic
conditions; trade policies; demand for and market acceptance of leased marine
cargo containers; competitive
                                       11
<PAGE>   12

utilization and per-diem rental rate pressures as well as other risks and
uncertainties, including, but not limited to, those described under Item 2,
Management's Discussion and Analysis of Financial Condition and Results of
Operations in the discussion of the marine container leasing business; Item 3,
Quantitative and Qualitative Disclosures about Market Risk and under Part
II -- Item 1, Legal Proceedings and Item 5, Other Information and those risks
and uncertainties detailed from time to time in the filings of the Registrant
with the Securities and Exchange Commission.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

     Not applicable.

                                       12
<PAGE>   13

                          PART II -- OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

     As the Registrant has previously reported, in February 1997, its former
outside auditors, Arthur Andersen LLP ("Arthur Andersen"), resigned as auditors
to The Cronos Group (the "Parent Company"), its subsidiaries, and all other
entities affiliated with the Parent Company, including the Registrant. The
Parent Company is the indirect corporate parent of CCC, the managing general
partner of the Registrant. CCC does not believe, based upon the information
currently available to it, that Arthur Andersen's resignation was triggered by
any concern over the accounting policies and procedures followed by the
Registrant.

     Arthur Andersen's reports on the financial statements of CCC and the
Registrant, for years preceding 1996, had not contained an adverse opinion or a
disclaimer of opinion, nor were any such reports qualified or modified as to
uncertainty, audit scope, or accounting principles.

     During the Registrant's fiscal year ended December 31, 1995, and the
subsequent interim period preceding Arthur Andersen's resignation, there were no
disagreements between CCC or the Registrant and Arthur Andersen on any matter of
accounting principles or practices, financial statement disclosure, or auditing
scope or procedure.

     In connection with its resignation, Arthur Andersen prepared a report
pursuant to Section 10A of the Securities Exchange Act of 1934, as amended, for
filing by the Parent Company with the Securities and Exchange Commission
("SEC"). As a result of the Arthur Andersen report, the SEC commenced an
investigation of the Parent Company on February 10, 1997. The purpose of the
investigation has been to determine whether the Parent Company and persons
associated with the Parent Company violated the federal securities laws
administered by the SEC. The Registrant does not believe that the focus of the
SEC's investigation is upon the Registrant or CCC.

     Current management of the Parent Company has been in discussions with the
staff of the SEC with a view to settling the investigation. The Parent Company
is hopeful of reaching a settlement of the investigation by the end of 1999.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

     See Item 5. Other Information.

ITEM 5. OTHER INFORMATION

     In 1993, the Parent Company negotiated a credit facility with several banks
for the use by the Parent Company and its subsidiaries, including CCC. At
December 31, 1998, approximately $33,110,000 in principal indebtedness was
outstanding under that credit facility (none of which had been borrowed by the
Registrant). As a party to that credit facility, CCC was jointly and severally
liable for the repayment of all principal and interest owed under the credit
facility. On August 2, 1999, all outstanding amounts under the credit facility
were repaid through the establishment of a new credit facility with two
financial institutions. CCC is not a party to the new loan agreement. The Parent
Company has guaranteed up to $10 million of amounts borrowed under the new
credit facility and, as partial security for this guarantee, the Parent Company
has pledged all of the capital stock held by it in Cronos Holding/Investments
(U.S.), Inc., a Delaware corporation that, in turn, owns all of the outstanding
capital stock of CCC.

     The Registrant is not a borrower under the new credit facility established
by the Parent Company, and neither the containers nor the other assets of the
Registrant have been pledged as collateral under the new credit facility.

                                       13
<PAGE>   14

ITEM 6. EXHIBITS AND REPORTS ON FORM 8-K

     (a) Exhibits

<TABLE>
<CAPTION>
        EXHIBIT
          NO.                         DESCRIPTION                           METHOD OF FILING
        -------                       -----------                       ------------------------
        <S>      <C>                                                    <C>
         3(a)    Limited Partnership Agreement of the Registrant,       *
                 amended and restated as of December 2, 1991
        3(b)     Certificate of Limited Partnership of the Registrant   **
        10       Form of Leasing Agent Agreement with Cronos            ***
                 Containers Limited
        27       Financial Data Schedule                                Filed with this document
</TABLE>

     (b) Reports on Form 8-K

     On August 20, 1999 and August 23, 1999, the Registrant filed a Report on
Form 8-K and a Report on Form 8-K/A, respectively, reporting the change in the
Registrant's independent auditors.

---------------
  * Incorporated by reference to Exhibit "A" to the Prospectus of the Registrant
    dated December 2, 1991, included as part of Registration Statement on Form
    S-1 (No. 33-42697)

 ** Incorporated by reference to Exhibit 3.2 to the Registration Statement on
    Form S-1 (No. 33-42697)

*** Incorporated by reference to Exhibit 10.2 to the Registration Statement on
    Form S-1 (No. 33-42697)
                                       14
<PAGE>   15

                                   SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this Report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                          IEA INCOME FUND XII, L.P.

                                          By  Cronos Capital Corp.
                                             The General Partner

                                          By  /s/ DENNIS J. TIETZ
                                             -----------------------------------
                                             Dennis J. Tietz
                                             President and Director of Cronos
                                              Capital Corp. ("CCC")
                                             Principal Executive Officer of CCC

                                          By  /s/ PETER J. YOUNGER
                                             -----------------------------------
                                             Peter J. Younger
                                             Chief Financial Officer and
                                              Treasurer of Cronos Capital Corp.
                                              ("CCC")

Date: November 12, 1999

                                       15
<PAGE>   16

                                 EXHIBIT INDEX

<TABLE>
<CAPTION>
EXHIBIT
  NO.                            DESCRIPTION                               METHOD OF FILING
-------                          -----------                           ------------------------
<S>      <C>                                                           <C>
 3(a)    Limited Partnership Agreement of the Registrant, amended and  *
         restated as of December 2, 1991
3(b)     Certificate of Limited Partnership of the Registrant          **
10       Form of Leasing Agent Agreement with Cronos Containers        ***
         Limited
27       Financial Data Schedule                                       Filed with this document
</TABLE>

---------------
  * Incorporated by reference to Exhibit "A" to the Prospectus of the Registrant
    dated December 2, 1991, included as part of Registration Statement on Form
    S-1 (No. 33-42697)

 ** Incorporated by reference to Exhibit 3.2 to the Registration Statement on
    Form S-1 (No. 33-42697)

*** Incorporated by reference to Exhibit 10.2 to the Registration Statement on
    Form S-1 (No. 33-42697)
                                       16