You've paid for the wedding dress, rented the tuxedo, hired a person to conduct your ceremony and said your "I do's." Now, you need that precious marriage license to arrive in the mail. It should take, at the least, about two weeks.
Considerations
One thing to keep in mind is the time to receive your marriage license depends on what U.S. state or Canadian province you live in and what state or province you were married in. The license will be printed where you were married. Depending on how far it has to travel to get to you dictates the time you'll wait for it.
Time Frame
It's the marriage official who's responsible for filing the papers for your official license through the government. The bride and groom are responsible to pay for the license before the wedding (time frames vary depending on where you live) and provide pertinent information. Marriage officials are obligated to file the forms within one week of the date of marriage, which means a turnaround of two to three weeks before you receive it in the mail.
Arrival
Once your license arrives, you can start changing your last name. Take your license with you everywhere you want to change your name.