Exhibit 31.3

CERTIFICATION

I, Harry Roessner, certify that:

1. I have reviewed this quarterly report on Form 10-Q of SunCom Wireless, Inc.;

2. Based on my knowledge, this report does
not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by
this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The
registrants other certifying officers and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) [omitted in accordance with Section III E. of SEC
Release No. 34-47986 and SEC Release No. 34-51293] for the registrant and have:

(a) designed such disclosure controls and
procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those
entities, particularly during the period in which this report is being prepared;

(b) [omitted in accordance with Section III.E. of SEC
Release No. 34-47986 and SEC Release No. 34-51293];

(c) evaluated the effectiveness of the registrants disclosure controls
and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures as of the end of the period covered by this report based on such evaluation; and

(d) disclosed in this report any change in the registrants internal control over financial reporting that occurred during the registrants most
recent fiscal quarter (the registrants fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrants internal control over financial reporting; and

5. The registrants other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial
reporting, to the registrants auditors and the audit committee of the registrants board of directors:

(a) all significant
deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrants ability to record, process, summarize and report financial
information; and

(b) any fraud, whether or not material, that involves management or other employees who have a significant role in the
registrants internal control over financial reporting.



|                        |  |                    |  |                                            
|----------------------- |  | ------------------ |  | -------------------------------------------
|Date: November 13, 2007 |  |                    |  |                                            
|                        |  | /s/ Harry Roessner
|                        |  | Name:              |  | Harry Roessner                             
|                        |  | Title:             |  | Vice President of Accounting and Controller