Thanks all.

Both cards earn me avios right now, but Chase sends me letters about my address every so often. I’m guessing from the story above that if I leave things as they are, I can probably keep earning both simultaneously but if I change to a US address I’ll have problems should I ever want to change it back.

What do you mean about different taxes and fees, Flyingnomad? Sounds like one country has higher fees, which one? I’ve never been able to compare, only being registered in the UK.

Does anyone know the answer to my question about being locked out of making changes for six months—is it just changing addresses that we’re blocked from if we change an address? Or is it everything to do with the account, meaning also HHA and F&F?