The Oyster card is very useful to me for traveling around London. This year I reused the one from last year and needed an account statement for travel refunds. So I tried to register my card. I got stuck at various places, it didn’t like my phone number nor my Zip code (being in a different format). Searching around, I find that it’s simply impossible to register with a non-UK address.
I used my hotel address, with 11 zeros as phone number. That worked. Now I can sign in, peruse my travel history, and get a statement.