Early on with kindles before they had the rest of world kindle store you had to buy from the US store (As an early international kindle buyer I had a US account

Early on with kindles before they had the rest of world kindle store you had to buy from the US store (As an early international kindle buyer I had a US account) I migrated to the UK store as some books I wanted were in the UK store but not the US. So far I've not regretted this (some books are earlier in the US but some are earlier in the UK) I'm pretty sure you can migrate back but last time I looked I needed US address (easy as my sister lives in CT) and it wasn't obvious if my lack of US credit card would cause me problems later (since credit card auth checks often use addresses).