Sheeran has been vocal on how he had absolutely no interest in writing a Christmas song when John first approached him with the idea a year ago. When he joined Jimmy Fallon for The Tonight Show Starring Jimmy Fallon, Sheeran explained that "I've always been against – it's not that I don't like Christmas, I love Christmas. But in terms of doing a Christmas song, you need to chuck the kitchen sink at it. If you're going to do it, you got to be able to do it."

As far as the song's title, Sheeran revealed that he and John had expected to find numerous songs titled "Merry Christmas" when they decided they wanted to go for a more simple title. However, they soon discovered that they could not find a single song with the name "Merry Christmas," which solidified that their collaboration was meant to be.

Sheeran and John first began to tease their single back in October, ahead of the release of Sheeran's newest album, = (pronounced "equals"). Sheeran went into more detail about how John had rung him up asking for a collaboration after sharing his excitement that his song "Step Into Christmas" was continuing to do well on the charts. John explained that he wanted to write another Christmas song and asked Sheeran if he would be interested in doing so. And with sleigh bells ringing, "Merry Christmas" is now ready to arrive.