Client mailed estimated 2018 tax due yesterday, April 15th, but didn't include form 1040-V. To make matters worse, she put her business EIN in the memo, not her SSN.

[SteeleCo]

This was the payment that was to be made with her extension.  I made sure the extension was filed an accepted yesterday so that part is taken care of.  But what should I do about her payment?  Should I advise her to put a 'stop payment' on the check and resend it today?  Or just wait on the IRS and see what they do?  I've never had this happen before so I'm not sure what to expect?  Any help would be greatly appreciated!

[TaxGuyBill · Accepted solution]

I would think it would be fine.

The check has her name and address, which should match up with what the IRS has.  It also has an EIN, which is tied to her Social Security Number.

It is possible the payment may take a while to post to her acccount, and/or you he may need to call the IRS at some point to make sure it is applies to her 2018 Form 1040 payment (rather than 2019 Estimated Tax Payment or whatever else), but I would think the end result would be fine.