With Christmas around the corner, many of you will be scrambling to shop for (and order) presents in time to post them to your loved ones around the world.
With that in mind, we've listed Royal Mail's all-important final delivery dates, so you can ensure you don't leave it too late to send Uncle Dave's socks in time.
This year, Royal Mail says you can create your own stamps, using its Smilers service, where you can upload family photos to be used as stamps. While it's also worth looking out for this year's Christmas stamps - designed by primary school pupils for the first time in over 30 years.
Regrettably, Royal Mail says it's already too late to guarantee Christmas delivery to anywhere in the world using the cheaper surface mail option; but you can still send cards and parcels by Airmail (below).
Wednesday 18 December: 2nd Class and Royal Mail Signed For
Friday 20 December: 1st Class and Royal Mail Signed For
Monday 23 December: Royal Mail Special Delivery Guaranteed
Wednesday 4 December: Asia, Far East (including Japan), New Zealand
Thursday 5 December: Australia
Friday 6 December: Africa, Caribbean, Central & South America, Middle East
Monday 9 December: Cyprus, Eastern Europe
Tuesday 10 December: Canada, France, Greece, Poland
Friday 13 December: USA
Saturday 14 December: Western Europe (excluding France, Greece, Poland)
HM Forces mail
Friday 29 November: Airmail to Operational British Forces Post Office
Friday 13 December: Airmail to Static British Forces Post Office
If you've missed the last posting date, you can still use Royal Mail Sameday courier service, which will deliver on Christmas Eve and Christmas Day - but expect to pay for the privilege.
Royal Mail deliveries
If you are wondering about which days you'll be visited by a postman or postwoman during the festive season, it's worth noting there will be normal deliveries on all days except: Sunday 22 December, Christmas Day; Boxing Day; Sunday 29 December; and New Year's Day.