Can I use my maiden name on baby’s birth certificate?

I have my mums maiden name and my dads last name as double barrel

I'm not married to my partner but we plan to in many years to come. Baby will have his surname so when we get married we'll all be the same. I want to personally avoid double barrel.

I think they have to use whatever name is currently on your driving licence &/or passport

I’d contact your local birth registration service. With my first we had to fill the forms online then check and confirmed they’d copied the information correctly. We had to give ID and confirmation of who we were as well. I’m not married and was told if we were to get married we’d have to have new certificates issued to reflect the change too. A friend of mine was totally different in a different town. We were just at the back end of lockdowns though so could have changed since.

You'll have to register using the name on your driving licence/passport. A deed poll takes literally 5 minutes and is free to do. Just look up the wording and write it out with your old name and new name, get 2 witnesses to sign it and you're done. You can then use that to get a new passport, driving licence, change your name with the NHS/bank/utility companies, etc. There are companies that you can pay to do the deed poll but you're literally just paying for fancy paper. I changed the bank and NHS first (just walked in, handed it to them and asked them to update their records). Then use their letters with your new name plus the deed poll to get your new passport - if you get it on a rush, you'll easily get it back before you have to register the baby.

I have recently supported a mum to register baby through my work, she didn’t have any form of ID to use at the registry office. She was asked to use whatever name she uses for benefit payments, which is apparently different to her legal name, however they did not ask for any proof.

I was in exactly the same situation as you when my first was born. I was not allowed to use my maiden name on the birth certificate. I had to use my married name which was my legal name at the time. I had to show ID and the names had to be the same. Like you I knew I was getting married shortly after so I just sucked it up - I figured I’m not going to lie to my son about being married before so no need to hide it. If you do want to get rid of the name the deed poll option sounds simplest! X