Different last name to your baby

It shouldn’t be but when travelling alone with baby bring their birth certificate, letter of consent and signed/dated copy of your husbands passport just for piece of mind

I’ve been travelling to and from Poland with exactly the same set up as yours and never been an issue

The only thing the polish gov might want is for your children to have an id / polish passport…

Hey, I am in a similar situation with my family. Each time I travel without my husband, I’m often asked to prove that I’m my son’s mother. I carry marriage certificate with me (I have few spare) and a photo copy of my son’s birth certificate in my phone. I also registered my son in Poland and always using his Polish ID when entering or leaving the country. I don’t know if you’re aware that every Polish citizen must show polish ID while entering/leaving the country. Dowód osobisty is free and only 1 parent is needed to sign the docs to request it.

I travelled with my baby girl on my ow once and had no problems at Luton Airport /I have polish passport and last name, she has British passport and dad's last name/ and no one asked any questions. I guess as everywhere it depends who you come across, I'd suggest get a birth certificate just in case.