The Shake It Off singer had been away from the DJ since November (15) when she embarked on the final leg of the 1989 World Tour in Australia and New Zealand, which ended in Melbourne on Saturday (12Dec15).

Taylor flew back in time to spend her 26th birthday with her boyfriend at a Christmas-themed party at Iovine's house in Malibu, California. The festive bash was also held to celebrate the birthday of Iovine's daughter Jessica.

The party was held in a marquee, which housed a Santa's grotto, and a fake snow slope was constructed in the garden.

Pictures on show a mini petting zoo containing penguins and reindeer.

A video posted via messaging app Snapchat shows Taylor, Calvin and DJ Snake posing for a photograph with Santa and Mrs. Claus.

Guests also included Taylor's mum Andrea, and Gwen Stefani and her boyfriend Blake Shelton, according to

Taylor and Jimmy also announced an Apple Music project on her birthday - a live concert film taken from a show in New Zealand last month (Nov15).

It will feature behind-the-scenes footage and appearances from her special guests including Mick Jagger and Justin Timberlake.

To celebrate her birthday, publishers Simon & Schuster also announced a contest for Taylor's fans to contribute to a book about the singer. The scrapbook will be released on 24 October (16) to coincide with the 10-year anniversary of her debut album.

Fans can enter the competition to name the book, design the cover, and earn an 'honorary author' title. They can also submit their own photographs and drawings for inclusion in the project. Taylor is not involved and has not endorsed the book.