Client mailed 2019 5500 instead of filing through EFAST - now what?

Just discovered that client mailed their 5500s for 2018 instead of using EFAST.  Does anyone know what happens to 5500s that get mailed?  I assume they are treated as not having been filed and we need to do a delinquent filing and pay the penalty?

Delinquent filing with payment would be safest option and probably cheapest option.

Thanks Lou.  That is my thought as well.  The client was trying to save some money and do the 5500s themselves and did not realize that mailing was no longer an option.  Not a bad idea given that they were simple returns but they missed one important detail.....now they will pay more in penalties than what it would have cost for me to do it for them.  

Yep. Don't let them off easy. Charge what you would have charged.

You can check the filing status on the EFAST site.  Maybe it was accepted?  Stranger things have happened.