"We want to help you get your cards and gifts to family and friends in good time for Christmas, so we’ve provided a handy list of last posting dates. And to make Christmas 2013 with the Post Office a little easier we’ve also created a simple festive reminder service. Just let us know where you’ll be sending your items to and we’ll let you know when it’s time to post them."
Royal Mail - Last Recommended Christmas 2013 Posting Dates UK
First Class - Friday 20 December
Second Class - Wednesday 18 December
Special Delivery - Monday 23 December
Royal Mail - Last Recommended Christmas 2013 Posting Dates International Airmail
Western Europe - Saturday 14 December
USA - Friday 13 December
Eastern Europe - Monday 9 December
Australia - Thursday 5 December
Asia, Far East (including Japan), New Zealand - Wednesday 4 December
Christmas - Last Posting Dates 2013 - Post Office
Cool Cards - Christmas Cards