MyWorks "Customer Mismatch" Error: What It Means and How to Fix It

Orders from your WooCommerce store stop syncing, and the MyWorks Sync log shows "Update Error: Customer Mismatch." The affected orders stay in WooCommerce, but they won't post to QuickBooks Online until the conflict is resolved. Here's what the error means and how to fix it.

What the error means

QuickBooks Online doesn't allow two invoices or sales receipts to share the same number. The error appears when a WooCommerce order number, say #1042, already exists in QuickBooks under a different customer. MyWorks sees that the number is taken by what looks like a different sale, and it stops rather than overwrite that record. MyWorks describes the cause and this protective behavior in its own help article.

Why it happens

This usually comes down to two number ranges overlapping. Typical situations are:

• The store's order numbers fall in the same range as invoice numbers already used in QuickBooks.
• Invoices are also entered by hand in QuickBooks, or arrive from another sales channel.
• Order numbering changed or was reset after a migration.

How to find the records that collide

1. Get the list of failed orders from the MyWorks sync log and note each WooCommerce order number.
2. Search for each number in QuickBooks Online, checking the transaction type your sync creates.
3. Compare the customer, date and amount. If all three differ from the WooCommerce order, it's a genuine collision. If they match, you're likely looking at an order that already synced, which is a different problem.

For a long list, export both sides to a spreadsheet, match on number, and flag the rows where the numbers match but the customers differ. Don't edit or delete anything in QuickBooks until you know what each record is.

How to fix it

1. Sync using the next available QuickBooks number. MyWorks calls this the most common and easiest fix. A setting makes the sync ignore the WooCommerce order number and use the next free QuickBooks number. The trade-off is that QuickBooks and WooCommerce numbers no longer match, so plan how you'll trace an order later.
2. Renumber the conflicting QuickBooks record. If the older QuickBooks invoice is a separate sale, give it an unused number. Confirm it's a different transaction first, and remember a renumbered invoice may already be in a customer's hands.
3. Move the WooCommerce numbering out of the way. MyWorks' guide points to a sequential order numbers plugin so the two ranges stop overlapping.

Check your work afterward

• Re-sync the failed orders and confirm they all appear in QuickBooks.
• Check that totals match the WooCommerce orders.
• Confirm nothing was duplicated or overwritten.

Need help?

If many orders are failing, or you're unsure which records are safe to renumber, this is the kind of repair covered on our Sync Repair page. For a sync that needs a proper rebuild, see WooCommerce to QuickBooks Online integration.