With Christmas fast approaching Royal Mail have published the last Christmas posting dates on their website. It might seem a long way off but it's worth planning ahead and getting your cards in the post early particularly for overseas destinations. The posting dates are in full below on at the following link. http://www.royalmail.com/greetings
  UK
  Thursday 13 December   
Standard and Mail Order Return Parcels
   
  Tuesday 18 December   
Second Class and Recorded Signed ForT
   
  Thursday 20 December   
First Class and Recorded Signed ForT
   
  Special DeliveryT
  Friday 21 December    
Special DeliveryT with Saturday Guaranteed
   
  Saturday 22 December    
Special DeliveryT
   
  International Surface Mail
  Friday 28 September   
Africa, Asia, Australia, Caribbean, Central America, New Zealand and South America
   
  Tuesday 2 October   
Far East (except Hong Kong and Singapore), Middle East
   
  Tuesday 16 October   
Canada, Hong Kong, Singapore, South Africa and USA
   
  Tuesday 6 November   
Cyprus, Eastern Europe, Greece, Iceland, Malta and Turkey
   
  Tuesday 20 November   
Western Europe
   
  International Airmail
  Wednesday 5 December   
Asia, Australia, Far East (including Japan), New Zealand
   
  Friday 7 December   
Africa, Caribbean, Central America, Middle East and South America
   
  Monday 10 December   
Canada, Eastern Europe and USA
   
  Wednesday 12 December   
Western Europe
   
  British Forces Post Office (BFPO)
  Friday 30 November   
Airmail to Operational BFPOs
   
  Friday 14 December   
Airmail to Static BFPOs