Around £8m worth of special Olympic and Paralympic stamps were sold during the London 2012 Games, helping the Post Office to increase its profits.
The stamps featured Team GB and ParalympicsGB members who won gold medals and proved hugely popular with consumers and collectors.
More than 500 branches opened on Sundays during the Games, many for the first time, so the stamps could be sold the day after a gold medal victory.
In its first trading statement since being separated from the Royal Mail, the Post Office said its operating profit in the first half of the financial year was £61m, up by £5m on the same period last year.
Turnover increased by £1m to £501m, with “continued strong performance” in the mail business, especially packets and special deliveries.