Christmas Jumper Day
People take part in an attempt to break the world record for the most people wearing Christmas jumpersGetty

Four years after the first official Christmas Jumper Day was launched, Save the Children has joined forces with ITV's Text Santa to raise thousands to help disadvantaged children over the festive period. Around four million people are expected to wear a Christmas jumper on 18 December this year, donning extravagant knitted designs for a good cause.

Last year, Save the Children raised £4m (€5.52m, $5.97m) from donations – but they hope to raise even more now they have teamed up with Make-A-Wish UK and Macmillan Cancer Support to make the day even bigger. For inspiration, check out our guide to the best festive wear for Christmas Jumper Day.

How can I do my bit in a Christmas knit?

You can sign up to get your Text Santa Christmas Jumper Day kit at itv.com/textsanta. Get together with friends or ask people at work to dig out their best Christmas jumpers and donate to Text Santa. The money you raise will help Macmillan Cancer Support, Make-A-Wish UK and Save the Children, giving hope to families in difficulty at Christmas.

You can also tune into ITV on 18 December for the Text Santa Christmas Jumper Day show, for a mix of comedy, live music, celebrity guests and film appeals which show exactly where your money is going. The three-hour show will feature Alesha Dixon, Caroline Flack, Amanda Holden, Holly Willoughby, Paddy McGuinness and more.

Can pets join in?

Of course - just remember to ask their permission and donate on their behalf. For inspiration, see some of the mutts and moggies below who have dug deep for charity.