Completion day close to mortgage expiry date

Mr_Potato

As a hypothetical question (we could find ourselves in this position if our vendors solicitors don't pull their finger out), is it okay to complete at any point up until your mortgage expires?

Or should there be a 'buffer' such as 2 weeks, prior to expiry to ensure that if completion doesn't happen on the agreed day, a notice to complete can still be served, for example.

Trying_to_be_good

I'd say you want to exchange a couple of weeks before the expiry, to be fairly sure the completion will happen.