Mother-in-law refuses to accept I didn't change my name

Had a few relatives do this. Some just didn’t understand (thought women had to change names by law). DH and I don’t have a joint account (14 years on). I would either ask them to correct it (a pain for them) or just didn’t cash them. I dont think it’s much of a gift If it’s addressed to someone else.

Yes you can bank it. My GM died last year and left me a small amount of money, I presume her will was written before I married and the cheque was made out to my maiden name.
The bank (Natwest) allowed me to bank it, I just needed my marriage certificate and drivers license as ID.

yeah you can. I double barrelled part of my name with my husbands to make a new surname and I got lots of cheques at my wedding which were written to my maiden name or my husbands old last name neither of which were my actual last name then. Because you can clearly see where my new last name came from if you look at the marriage certificate and the bank knew who I was and what my old name was... they let me put cheques written in either name into my bank.
So just go in with some ID and the marriage certificate and have a word with them, it should be fine.

and your MIL is nuts but it doesnt really make any difference what she accepts... the reality is you didnt change your name and thats the end of it!

Why would you accept it?

I'd send it back with a really polite thank you note explaining you can't pay it in to a bank as that's not your name.

Send it back with a little note saying sorry unable to cash this cheque as it has the incorrect name on it. As you know my name is xxxx xxxxx. Many thanks.

Pay it into the joint account at the machine. Never had any issues doing this even when in wrong name.

Your MIL is being exceptionally rude .

You possibly can. I did this once about 28 years ago, but banks might not allow it now.

Why not send it back. I have once or twice for either my DC or me, and folk were happy to send another cheque.

My mil is the same about me keeping my name. On many occasions she has told me stories about her "daft" neighbour who kept her own name after marriage...a crazy lady she was!
I have also had a cheque in my married name(for my kids) given to me. I brought it to the bank and they lodged it into my account no problems. I am in Ireland but I assume it's the same in the UK.