Postal deliveries will be affected by the extra congestion generated by the Olympic Games, with some mail held in the system for an extra day, the Royal Mail said today.
A £1 charge will also be introduced by Parcelforce for delivering to parts of London affected by the Games and Paralympics this summer.
Postmen and women will start their delivery rounds earlier because of the extra travelling time they will need due to transport restrictions.
Households and businesses in the capital were urged to post mail earlier in the day than usual, and a day earlier if possible.
Some mail may be in the system for an extra working day because of the impact of increased journey times.
Mark Thomson, Olympic director for Royal Mail, said: "Royal Mail is geared up to serve London during the Games. We will continue to collect and deliver six days a week despite the inevitable impact on the capital's transport system because of the Games."
Parcelforce Worldwide said that, in common with other delivery companies, it will be introducing a small extra charge, of £1, for delivery in areas affected by the Games, which will replace the 50p charge which normally applies because of the London congestion charge.