You may add a positive buffer if you want to collect extra funds to cover costs associated with:
For reasons like those above, you may add a positive percentage or flat rate buffer such as the ones shown in the following examples:
You may add a negative buffer if you want to absorb some of the shipping costs yourself, lowering the cost to your customers. Here is an example:
For this [or another] reason, you may add a negative percentage or flat rate buffer such as the following:
There are 4 types of buffers that you can add to your account:
Account buffer - Adds a buffer to all service levels, for all carriers.
Carrier buffer - Adds a buffer to all service levels, for a specific carrier.
Service level buffer - Adds a buffer to a specific service level.
Duty/tax buffer - Adds a buffer to the duty and tax amount.
Add shipping buffers
You can add positive and negative buffers to your shipping rates by adding them at the carrier level or on specific service levels/shipping options (shipping costs), which alter the shipping amount displayed and charged at checkout.