Add a charge to order already paid

Shopify Plus

Topic summary

Main issue: Whether a previously paid order can have an extra fee added to absorb a small remaining credit after item substitutions.

Key points:

  • Policy/limitation: You cannot add cost to an order that’s already been paid. Cited reason is Shopify security—preventing post-payment, unapproved charges. Recommended flow for online orders: refund the returned item(s) and create a new order for the replacement item(s).
  • POS context: The order originated in POS (point of sale). While handling can differ in POS, no POS-specific method to add a fee post-payment was provided.

Scenario described:

  • Original order: 50 units of Product #1 and 50 of Product #2, fully paid. 50 of #1 and 20 of #2 shipped; 30 of #2 backordered.
  • Customer returned 20 of #2; later decided against #2 entirely. All 50 of #2 were returned without refund. 30 units of Product #3 were added instead.
  • Result: Small remaining credit due to price difference. Salesperson wants to apply it as shipping/handling to zero out.

Outcome/status: No way to add a fee post-payment was identified. Suggested action is to refund the remaining credit; otherwise, handle as separate refund/new order. Discussion remains open for POS-specific alternatives.

Summarized with AI on January 7. AI used: gpt-5.
1

We have an order that one item in the order was returned and a different item substituted by the customer.

The item was returned and the new item added to the order.

There is a small remainder in the order due to a slight difference in price/quantity.

How can I add a fee or something to even out the small discrepancy?

2

I don’t believe it’s possible to ‘add cost’ to an order that’s already been paid. That would be against Shopify’s security policy, as then any ‘shady’ store owner could just charge the customer any amount they want without approval, once they’ve received an order (would potentially allow for a lot of bad situations to occur).

The way this situation should of been handled is to refund the price of the returned item, and then have the customer place a new order for the new item (ie. there would be 2 separate orders, so then there wouldn’t be any discrepancies).

This process is a bit different for POS orders, but for online store orders, the above is the correct way to handle things.

3

This situation is as follows:

The order originated in POS with 50 units of Product #1 and 50 units of Product #2.

Order fully paid, 50 units of Product #1 and 20 units of Product #2 sent to customer.

The remaining 30 units of Product #2 were out of stock and waiting to be sent.

Customer decided they don’t want Product #2 and returned the 20 units, Salesperson removed the 20 units from the order and did not refund the money.

Customer decides they want to replace the 50 units of Product #2 with 30 units of Product #3.

I returned the 30 units of Product #2 were not sent and did not refund the money.

All 50 units of product #2 has been returned and no money has been refunded

30 units of Product #3 added to order.

The price of 30 units of Product #3 is very close to the price of 50 units of Product #2.

The order now has a small amount of unspent money remaining in the order that can be refunded.

The salesperson requested that the small amount of unspent money remaining in the order be used for some sort of fee because of the extra “shipping and handling” cost incurred by the changes to the order, zeroing out the remaining credit on the order.

The order is paid in full and no additional charges would incurred.

The obvious solution is to just refund the small credit.

The salesperson just wants the small credit to be taken as shipping and handling.

I this made sense.