BobKamman
Level 15

Fortunately, just one payment here -- they had a large capital gain early in the year and wanted to cover it in the quarter received.  

What do the Form 1040 Instructions say about this?

"If you and your spouse paid joint estimated tax but are now filing separate income tax returns, you can divide the amount paid in any way you choose as long as you both agree. If you can't agree, you must divide the payments in proportion to each spouse's individual tax as shown on your separate returns for 2020. For more information, see Pub. 505. Be sure to show both social security numbers (SSNs) in the space provided on the separate returns."

They left out the part, "Don't be surprised if we screw this up."