Many parents will encourage their children to write a letter to Santa - and they usually get a believable response.
Father Christmas will encourage them to continue to be good throughout the rest of the year so they can make it onto the nice list, rather than the unwanted naughty one.
This year, however, children will be able to get their very own personalised letter response from the big man himself as Royal Mail and Hallmark have teamed up to respond to children - but there's a deadline and it's coming up very soon.
In fact, you need to get your letters posted to Santa by Friday, December 9, and Royal Mail have warned parents to not forget their stamps.
Parents should also get their children to write their full name and address on the envelope clearly, so that Santa is able to respond to them directly before Christmas day.
On the Royal Mail website, Santa also kindly says: "Make sure you remember my mince pie and Rudolph's carrot!"
Kids will need to be quick though, as they need to post the letter by the end of this week - so they need to get their best writing set out ASAP.
Families are also being warned to send their letters out as soon as possible as it's a very busy time of year, and of course, Royal Mail is striking.
Letters should be sent to: Santa/Father Christmas, Santa's Grotto, Reindeerland, XM4 5HQ.
A response should be given within 10 days of sending out a letter - so you and your children can wait eagerly at the front door for the post.
And, if you don't get a response in the timeframe you'd like, or your little elf is super keen, you can download the card he's set to send back on the Royal Mail website.
Will you be sending a letter to Santa this year? Let us know in the comments.
