How do I find bills that were entered twice across our companies?

1) Open Accounts → Duplicate Invoices (/accounts/duplicate-invoices). It reads a stored group-wide scan rebuilt overnight; Recheck runs it now (up to a minute on a large ledger). 2) Choose supplier bills or sales invoices. 3) Read the headline: open clusters, across entities, Billed twice and Recoverable by voiding. 4) Work the table, highest recoverable first — each row is a cluster of copies with the suggested action. 5) Open a cluster, use Fix in Xero to void the open copy (or raise a supplier credit note if every copy is settled), then Mark resolved. Dismiss — not a duplicate — if it is not one. Nothing on this page deletes an invoice.