Stimulus checks

Did you file a joint 2020 return?    Are you divorced yet ?  If yes when was the divorce final? 

Will you file a joint 2021 return?  Did the stimulus checks get deposited into a joint account ?   

Did either of  you get the 6419 letter from the IRS yet ?

If you split the stimulus checks with your ex spouse, but the checks all came to you, you still need to claim the entire amount on your return.  You should have already received letter 6419 from the IRS with the amount they know they sent you.  If you enter an amount other than what is on the letter, they will make an adjustment to your return and it may take longer to process.

What you enter on your return from letter 6419 will just be deducted from the rest of what you would be receiving.  So, if you received $1,500 in advanced payments (and are still eligible), you will still get the other $1,500.  

The IRS doesn't care if you split it with your ex or not.  Also, only one of you should be getting this payment and claiming this payment on your return.  A child can only be claimed by one parent at a time.

If the payments came in your names jointly, you will both be getting a letter with half of the total payments.  If you received $1,500 that came in both your names, your letter will show $750 and their letter will show $750.  If you are claiming your child this year, you would then get the remaining $2,250 on your return since the amount they received does not affect your return as you will not be filing a joint return. 

Basically, the remaining balance (amount whoever claims the child received minus the total credit) will go to the parent claiming the child in 2021.