The Royal Mail are once again helping Santa out by delivering the children's letters to him. To ensure Santa can reply in time letters need to reach him by 11 December at:
Santa/Father Christmas,
Santa's Grotto,
Reindeerland,
XM4 5HQ
Be sure to put a stamp on the envelope and include the child's name and address clearly. Note that the reply from this service is a standard letter and is not personalised.