Extra Fees for WooCommerce

The current formula for calculating the payment gateway fee does not calculate the correct amount for the vendor to receive the full amount of the original cart order amount from the credit card payment gateway processor.

The current formula calculates an amount based simply on the payment gateway input variables (for example 2.9% + $0.30 for a USA issued credit card in a Stripe credit card transaction) and adds that to the cart total.

When the transaction is actually processed by Stripe (or other card processor), they calculate the fee on the “new” cart total (original cart total plus calculated and added payment gateway fee). Therefore, the amount deposited into the vendor’s account does NOT match the original cart amount. Depending on the original cart total, the resulting difference may be off by a few cents to a few dollars.

Example transaction: Original cart total (or sub-total) is $30. This is what the vendor wants deposited in their bank account.
Using the current formula, the plugin calculates the extra fee as (($30 * 2.9%) + $0.30) = $1.17 payment gateway fee. So the new order total is $31.17.
The problem comes in when the payment gateway calculates the fee, they use the $31.17 amount (NOT the original cart amount). Therefore, the payment gateway calculates the fee to be (($31.17 * 2.9%) + $0.30) which equals $1.20 instead of the $1.17 “Extra Fee” calculated by this plugin. So, the amount deposited in the vendor bank account is only $29.97 instead of $30.

The formula in the “Calculate Fee” code could be modified to calculate the correct payment gateway fee so the original cart total is deposited into the vendor’s account by the card processor. We have developed an alternate formula to calculate the correct amount and would possibly be willing to share it.

Since our website only uses the plugin to add the “payment gateway fee” and does not use other features of this plugin, we cannot say whether changing the “Calculate Fee” routine formulae will affect any other features / amounts of the “Extra Fees”.

It would be nice if the plugin calculated the correct payment gateway fee for the vendor to receive the original cart amount.