help me find a childhood book

[whowouldknow]

I am trying to track down a book from my childhood-I don't think it was a classic or any way legendary but due to a recent bereavement I am keen to track it down.

It was a Christmas based story about a postman and his daughter -there was no mother but I cant remember why. The postman had to try and decipher poorly written addresses and somehow he and his daughter ended up on an adventure to the north pole and Santa. I think there was a dog involved as well.

I am struggling to remember any more but if this sketchy description rings any bells let me know!