Once your buyer has satisfied their mortgage contingency and you have finalized a closing date, you can:
Notify utility companies of your move
Electric
Homeowner Insurance
Water/Sewer
Gas/Oil
Telephone
Cable
Sanitation
Notify others of your change of address
Relatives/Friends
Post Office
Health Insurance
Credit Cards
Car Insurance
Social Security
Life Insurance
Newspapers
Banks
Investment Firms
Clubs
Dept of Motor Vehicles
IRS
Doctors/Dentists
Schools
Magazines