From Longman Dictionary of Contemporary Englishin advance (of something)in advance (of something)BEFOREbefore something happens or is expected to happen I should warn you in advance that I’m not a very good dancer. Many thanks, in advance, for your help.six months/a year etc in advance Book tickets 21 days in advance. Could you distribute copies well in advance of the meeting? → advance
Examples from the Corpus
in advance (of something)• Admission is $ 7 at the door, $ 6 in advance and $ 5 for Tucson Blues Society members.• Admission is free to all ticket holders and there is no need to book in advance.• The walk is suitable for all the family and places must be booked in advance.• The Assembly passed legislation which required organizers of demonstrations to apply three days in advance for government approval.• It was another to tell him in advance you were going to.• Although it cuts down on your freedom, Steves now recommends making make reservations at least a few hours in advance.• Most are commissioned but proposals can be made in advance to the News and Views Editor.• So Whitney now works out arrangements with her partner in advance to avoid problems down the road. 