Mailing a parcel to the U.S.?

You can use any box. Address it. Tape it securely with shipping tape, not masking tape or duct tape or scotch tape. Then you take it to the post office where they will weigh and measure it, and will sell you the right amount of postage depending how fast you want it to get there. Faster costs more. You will also have to fill out a customs form sticker which goes on the parcel, declaring what is in the parcel and what it's worth. You can use stamps, if you like, if you already have some, but it's better to buy the exact amount of postage for that parcel after they tell you what it will cost to mail it. If it costs $6.83 to mail the parcel and all you have are P stamps worth .85 each, you'll have to put 9 of them on it, and you will have put on 82 cents more than necessary.

If you're mailing a box, you need to measure and weigh that box first. Postage amount is dependent on weight and size.

You can find out the rate by clicking on the Canada Post website linked below: