Child Dual Passport Question

Hi all,

Just a quick question. I have a 10 week old baby who we have managed to already register with the U.S. embassy in London. He has now received his U.S. passport!

We were planning to go to the U.S. for Thanksgiving this year. And in the fog of having a newborn I completely forgot about applying for his British one! Oops.

My question is whether I absolutely have to do this. I'm worried that it won't arrive in time (plus they require you to send the child's other passports - i.e. his American one - as well). Is it absolutely necessary that he gets his British passport at this time? My concern is coming back to the U.K. at the end of the trip. Is he allowed to enter on a U.S. passport (He is a British citizen and I will have his birth certificate with me...)

Thank you x

He will need his British passport to re-enter the UK. 

It shouldn't take long at all to get, a few weeks at most.

Once we made the same mistake and only brought the US passports for my children when we travelled to the States.  Like KFDANCER said, it was a massive problem at the border because they had no visa to live in the UK.  Eventually the Border Officer let them in.