In your service history it will tell you when a service is due and what work is required for your car at that particular mileage mark. It will differ with each service and when quoting for a service a good garage will want to know mileage and what was done at the last service etc.
We don't know what car you have but it will be cheaper, and just as good if you take it to an independant garage rather than a main dealer for your car.