After you send a settlement to Xero, you can remove its sales invoice from inside Taxomate.
If Automatic sending is on, turn it off first (select Change next to "Automatic sending" at the top of the list). Otherwise Taxomate can send the deleted invoice again.
Option 1. The invoice is not reconciled with a deposit in Xero
One settlement or payout: open it, select More actions, then Delete entries from Xero, and confirm.
Several: on Settlements (or Payouts), select the rows. In the bar at the bottom, select More actions. Under Remove entries, select Delete accounting entries (the same item for payouts), and confirm.

Option 2. The invoice is reconciled with a deposit in Xero
In Xero, select the Business menu, then Sales overview.
Select the Paid box to open the list of invoices.
Select the blue Payment link in your invoice or bill. If you use new invoicing, select Less payment.
Select Options, then Remove & Redo.
Go back to Taxomate and open the settlement.
Select More actions, then Delete entries from Xero, and confirm.
