On my flight from London to Zurich yesterday, I was told twice (bag-drop and gate) that my passport would reach its 10 year duration soon and that I must renew it.

I'm aware of the Schengen rules: passport must have 3 months validity, and be issued less than 10 years ago, at the date of entry. However, as a Swiss resident this doesn't apply to me when flying to Switzerland. It may not even apply when flying into any Schengen country, but that's not my concern at the moment.

My concern is if BA get stroppy and don't let me board a flight to Switzerland with a valid, but over 10 year old, UK passport (and valid Swiss residence permit).

So, I check Timatic (via the United Airlines website) and it's vague. It says the 3 month rule applies even for Swiss residents, and even if you have no return flight booked - which makes no sense at all. And it never mentions the 10 year rule. So, the Timatic page I can find via UA isn't correct.

What do BA use?