Table of Contents
Overview
USPS Flat Rate box methods are popular with merchants who prefer offering fixed shipping rates while using predefined box sizes. These methods, including envelope options, rely on box dimensions. To access USPS flat rate methods, ensure your boxes are correctly configured, and the dimensional packing feature is enabled in ShipperHQ.
Setup
- Enable dimensional packing in the features section.
Add the desired USPS Flat Rate boxes/envelopes in the boxes section.
- On the basic tab, use the "Box Size" drop-down to select the predefined sizes for flat rate boxes/envelopes.
Go to USPS carrier > Basic > Active Shipping Methods and add the corresponding methods for the boxes you wish to use.
- For example, add the USPS Small Flat Rate Method if using the USPS Small Flat Rate Box.
Once set up, USPS will offer the chosen method when the appropriate box is used. 💡
⚠️ USPS insists on specific box dimensions and will not offer flat-rate methods if the packing box doesn't meet their standards.
Carrier Configuration
USPS shows all available Flat Rate methods if items in the cart fit any available Flat Rate Box.
Example: If an item measures 8x4x1 and you have USPS Small, Medium, and Large Flat Rate Boxes available, USPS will display all methods capable of accommodating the item.
To display only the cheapest Flat Rate at checkout, enable the "Show Cheapest Flat Rate" option under USPS Carrier > Basic > Account Settings.
With this example, only the USPS Priority Mail Small Flat Rate Box method appears, as the Medium and Large Flat Rate Methods are more expensive.
For configurations like hiding all other USPS methods when a Flat Rate Box is chosen, set up a Box Based Shipping Rule.