As far as I can make out, it’s up to your bank to contact you for a declaration of non-residency. Ours did so by e-mailing me a form, in English, which I printed off and sent back in the post. I think in theory a copy of your NIE counts as proof of non-res status, and your bank should have this already, so if they don’t contact you I think you’re all right. If your Spanish (or his English) is up to it, though, I would ask when you next see your bank manager, or e-mail him. If you’re thinking of the same Times article I saw, it’s a confused and self-contradictory piece of journalism (that’s The Times for you) which talks about certifying residence when they mean NON-residence. If you want to save some time on your next trip, take a few photocopies of your NIE certificate and passport with you (goes for your partner’s paperwork too), they might come in handy.