CHECKOUT421: Order tax rate unknown
What this means
This order refers to a tax rate your store no longer has, so its tax may be wrong.
A line on the order carries a tax rate that is not in the store's current tax tables — almost always because that rate was deleted or edited in WooCommerce after the order was started. WCPOS cannot look the rate up, so the tax on this order may not match what the store would charge now.
Your data
The order is safe. Only its tax amount is in question — check it before taking payment, and ask your store administrator about the tax rates.
Troubleshoot
At the till — do this before taking payment:
- Check the tax amount on the order. It was calculated with a rate your store no longer has.
- If the tax looks wrong, start the sale on a new order — a new order picks up the store's current rates.
On the store (WP Admin) — for the site administrator:
- Go to WooCommerce → Settings → Tax and check whether a rate was deleted or edited recently. Deleting a rate that open orders already reference is the usual cause.
- If a rate was removed on purpose, no action is needed beyond restarting any orders that were open at the time.
- If the store's tax rates have not changed, the POS may be holding a stale copy. Refresh it from Store health → Database → Tax rates → Clear & re-download — this affects only that collection and does not log anyone out. See Store health.
- If the code returns once the tax rates have finished downloading, open the log entry in Store health → Logs, use Copy (or Share) to send its details, and contact support with the order number.