I understand Notice 2014-35 to say that it applies to any DFVC filing submitted electronically and that the deadline for filing Form 8955-SSA required for a Form 5500 filed under DFVC prior to November 1, 2014 is December 1, 2014. (This would mean that any DFVC filing made after December 31, 2009 when forms were first required to be filed via EFast2 and before November 1, 2014 should have filed Form 8955-SSA by December 1, 2014 to avoid IRS penalties for the late Form 5500 filing.) Otherwise, the deadline is 30 calendar days after the DFVC filing. Thus, the Form 8955-SSA deadline for any DFVC filing made on or after November 1, 2014 for which a Form 8955-SSA is required is subject to the 30-day filing deadline.
Notice 2014-35 refers to the “later of” and gives an example explaining the application of the December 1, 2014 deadline:
“Any Form 8955-SSA required to be filed with the Service pursuant to this notice must be filed on paper by the later of 30 calendar days after the filer completes the DFVC filing or December 1, 2014. This requirement applies with respect to any DFVC filing submitted through EFAST2 (generally, all DFVC filings after December 31, 2009), regardless of whether the filing was submitted before the issuance of this notice. For example, if a DFVC filing for a delinquent 2008 Form 5500 was submitted in 2012 and information required to be filed under § 6057 was never filed for 2008, a paper Form 8955-SSA must be filed with the Service for the 2008 plan year by no later than December 1, 2014 to qualify for the relief provided under this notice.”
I'm always reminded to check the box on Line C, Part I (Special extension) on Form 8955-SSA, and enter "DFVC" in the space provided on Line C. The IRS will then determine whether you have also filed the late Form 5500 under DFVCP.