Customers have until December 21 to post First Class mail and December 22 to post Special Delivery mail.
Each year Royal Mail invests in additional resources for its Christmas operation to handle the festive mail bag. This has included recruiting 19,000 seasonal workers and opening nine temporary parcel sort centres.
Customers should ensure they use the postcode when sending their cards and parcels, write clearly and use a return address on their cards and parcels.
Further information is available at www.royalmail.com/greetings