From what I am aware, the NHS will only provide funding for what they deem 'core' procedures - namely hormones, occasionally laser hair removal - rather than 'aesthetic' procedures, which encapsulate FFS, Boob Augmentation and whatnot.
The NHS divides its care into Primary Care Trusts, which look after a certain region and hold the purse strings so to speak; they decide what to allocate their budget on. Some PCTs will allow funding for treatments, and some won't. It just depends on where you stay and how trans-sympathetic the PCT are.
Sorry for the sketchy info - the NHS provides a booklet for transitioning somewhere which might provide more details but this is all I could remember!
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