I claimed my son by accident when it's my ex's turn and I already filed and got my return

[bluedeb · Accepted solution]

You would need to amend your return to remove your son from being claimed as a dependent.  Amended returns must be mailed.  Your Ex can then claim his son on his return, he would have to paper file his return because an amended return takes 6 to 8 weeks to process so the IRS would not have cleared their system regarding you claiming your son for your ex to e-file.

How to amend (change or correct) a return you already filed

https://ttlc.intuit.com/replies/3288565

[fanfare · Accepted solution]

let your ex have two turns next year and the next