Measure your packages
- Envelopes thicker than 1/4 inch or uneven in thickness by more than 1/4 inch are considered packages instead of letters.
- Small bubble envelopes, if flat and light, can usually be sent as letters in the U.S. (only once has one of my customers had to pay extra postage, which I reimbursed), but are always packages for international shipping (I've lost money twice because I forgot this!).
- Large envelopes that are flexible (for example, holding a paperback children's book) can be mailed at a large envelope price instead of a package.
- Boxes longer than 12 inches on any side cost more to ship regardless of low weight.
- The biggest mistake sellers make is sending everything Priority Mail. Packages lighter than 13 ounces qualify for First Class parcel, which is just as fast as and sometimes faster than Priority Mail but considerably cheaper.
- Heavier packages are mailed Parcel Post, which takes about a week. If the price difference between Parcel Post and Priority Mail is minimal, go with Priority Mail to ensure faster delivery.
- UPS and FedEx are best reserved for extremely large, heavy, valuable, or fragile items.