We're off on holiday next month - with hotels, trips and car hire to pay whilst we're there. Car hire can be tricky as they 'block' a certain amount of your credit limit (its not taken, but its not available to use). Last time we went away, we got caught in the COVID mandatory quarantine and my card took an enormous hit, reached its limit and caused huge problems. Hopefully this won't happen again, but....how can I get my balance to zero just before we go (to give us maximum spend power if we get stuck again)

I normally pay by direct debit but, because of the time between spend and payment, my balance never gets to zero. Can I make a one-off payment and will this immediately 'wipe out' all pending transactions to get my balance to zero?