EXHIBIT
31.2



CERTIFICATION



I,
Jeremiah Silkowski, certify that:



|1. | I
    have reviewed this annual report on Form 10-K of SQN AIF IV, L.P.;                                                                                                                                                                                                                                                                           
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|2. | Based
    on my knowledge, this report does not contain any untrue statement of 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;                               
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|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;                                                
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|4. | The
    registrant’s other certifying officer(s) 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)) and internal control over financial reporting (as
    defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:
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|   | a)                                                                                                                                                                                                                                                                                                                                                 
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|   | b)                                                                                                                                                                                                                                                                                                                                                 
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|   | c)                                                                                                                                                                                                                                                                                                                                                 
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|   | d)                                                                                                                                                                                                                                                                                                                                                 
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|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
    (or persons performing the equivalent functions):                                     
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|   | a)                                                                                                                                                                                                                                                                                                                                                 
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|   | b)                                                                                                                                                                                                                                                                                                                                                 



Date:
April 15, 2019



|/s/
    Jeremiah Silkowski        | 
|--------------------------------- | 
|Jeremiah
    Silkowski            | 
|Chief
    Financial Officer       | 
|(Principal
    Financial Officer) |