Brits are being urged to cash in their £20 and £50 paper notes which are due to expire in just four days.
Colossal queues are expected at Post Offices across the country where £1.2billion worth of old paper notes have been deposited since January.
But staff are expecting a rush of customers this week, with £6billion worth of old £20 and £8billion of old £50 notes still in circulation, according to the Bank of England.
