How do I purchase a postal money order? Domestic money orders & international money orders. Money orders can be purchased at any Post Office™ location. To find a Post Office that sells International Money Orders, go to the Post Office Locator (click "Post Offices" > "Refine search" > "Money Orders") or call 1-800-ASK-USPS (1-800-275-8777). Money orders can also be purchased from rural carriers and some contract stations. Regular money orders can be bought at your local grocery store, bank or post office. There are some limitations to paper money orders, but they're easily worked around. For example, the amount can't exceed $1,000, but you can buy more than one at a time. So, if you need to send $5,000, just purchase five money orders worth a grand apiece.