Full disclosure: I'm the developer of BulkOps, a Xero add-on. The manual steps below work with or without it. If you run a rebates-heavy or returns-heavy business on Xero, month-end usually includes one specific chore: applying dozens or hundreds of credit notes to open invoices.
Source: [Dev.to](https://dev.to/sunxnx/xero-has-no-bulk-credit-note-allocation-heres-the-manual-process-and-what-i-built-instead-58bb)