Paying back maternity pay to NHS if you change trusts?

I don't know I'm afraid, not an NHS person.. hopefully someone will come along with the answer.

You might have some luck cross-posting this as well on the BabyTalk forum - there may be some maternity-leave mums who could help you out.

You'll need to speak to your HR, but I'm guessing that if it's a Whitley contract, probably not, but Trust contracts are often different, and less favourable.

We (junior docs) don't as long as you stay in the NHS but not sure whether it's the same for nurses.

You shouldn't, no. HR will often give duff advice but your union should confirm.

The only time I've ever heard anyone not getting SMP was people who were only on honorary contracts ie employed by, say, a university, and employed as a lecturer under an honorary NHS contract.