Nicola

I think we are both saying the same thing. Sometimes there are accidental denials (whether it's a plan sponsor or service provider level) and when it happens you need to provide proof of delivery/receipt that you mailed it on time.

We also send all of ours out in one batch/envelope with a list, and have never had any questions or problems. We make sure to send them either via USPS or FedEx with confirmation of delivery. www.form5500pros.com

The 5500 instructions indicate that the filing deadline for Master Trusts are within 9 1/2 months of the end of the plan year - they are not eligible for a Form 5558 extension. If your plan year was 1/1/18 - 12/31/18, that would make the 9 1/2 month deadline October 15, 2019 (that's a full 9 months plus the 15th day that goes into October). www.form5500pros.com

We've been instructed by the DOL to use the EIN of the firm. www.form5500pros.com

Unfortunately it happens. When it does, the plan sponsor needs to write a letter requesting reconsideration, providing an explanation and it should include a evidence of mailing prior to the extension deadline. The letter should also include a copy of the incorrect rejection letter. www.form5500pros.com