I did this just recently to extend the life of my points and because I thought topping the account up for €5 per 1,000 points was an ok deal. I cut it a bit fine with the expiry date of Tuesday 5th December. The points were bought on Sunday evening and they were in my account on Tuesday morning, so I think you should reckon with at least 48 hours, even though it took a bit less with me.

I’m going to try and stop doing this with hotel chains I rarely stay at, though, because it really is a hassle remembering (and costly forgetting) and the expiry limit of just one year if there’s no activity on the account is unacceptably short.