Ok, I've seen topics about using the POS API and enabling the new cash rounding feature, but nothing for using the orders api.
We use the orders api, and we need to start implimenting cash rounding. In the orders API the
rounding_adjustment is defined as:
Beta
Read only A positive rounding adjustment to the total of the order. This adjustment is commonly used to apply cash rounding when the minimum unit of account is smaller than the lowest physical denomination of the currency.
Great, it's read only. How do we get a value into it so we can pay for the order.
Example: we set up an order using the orders API (adding line items not using a catalog)
With tax it comes to $21.02.
if we decide to pay for that order with check or credit we pay $21.02 and everything is ok.
If we need to pay for it with cash, we need to pay $21.00. Alas, the payment amount must match the order total.
All of the search for help says to adjust the order total. (It doesn't say how to do that).
What makes the most sense is to fill in the rounding_adjustment, but that is a read only field.
How do we deal with cash rounding in the orders API directly, so we can apply a cash payment to it. We don't mind doing an API call to update the order to add the rounding, but alas with that field read only it just doesn't take.
Looking for help on how to do this.... WIth the current API (2026-08-19).
