I read yesterday, you don't need a license to keep in a tank, the license is a general license the shop get to sell them which covers you to own them, whether the shop then charge more to cover said license, which I imagine is inevitable, I'm not sure. Sorry for digging up an old post but they are legal to own provided you've bought them from a shop that has a license to sell them, that license fee the reason most shops probably won't sell them. Absolutely gutted myself to be fair, only type of cold/temperate fish I'd keep if they were more available