Explains how to add funds or set up auto-funding, Stamps.com auto-funding, and ShpStation Carrier Services auto-funding.
When purchasing labels using a balance-based postage provider, you'll be prompted to purchase extra funds in the Cost Summary page if your balance is too low to purchase the label.

However, you can add funds to your postage provider balance at any time or configure ShipStation to automatically purchase postage when your balance-based postage provider account hits a certain funding threshold.
For example, if you wanted to purchase $100 by default any time your account balance falls below $250, set the When balance drops below amount to 250 and the Automatically fund by this amount to 100. Then enter in the maximum number of times ShipStation should automatically purchase postage in a day next to Stop after this many times per day.
The option to manually add funds or set ShipStation to auto-fund are both located in the Carriers and Fulfillment section of your account settings. The process below outlines both options.
About Stamps.com Auto-Funding
This feature triggers ShipStation to add funds when ShipStation detects the Stamps.com account has fallen under a certain threshold and is not connected to Stamps.com's own Auto-buy postage feature that can be enabled when logged into Stamps.com directly. We recommend you only have auto-funding enabled in one location, as having the feature enabled in both ShipStation and Stamps.com can cause funds to be added twice.
Stamps requires a minimum purchase of $10.