Have you seen the actual check? If the info you have available shows it to be in the name of the trust, it sounds like she has figured out that she's gonna be the one paying the tax on it and is trying to pull a fast one on you. If the check is coming from your retirement account at work, you need to have a Come to Jesus meeting with the HR person and tell them it needs to be straightened out, like YESTERDAY. Their screwup could cost you several thousand $$ in taxes you shouldn't be responsible for. Starve the ex out as long as you can and she will get more agreeable. Sorry for your troubles.....been there, done that!