A customer system change can split your supplier identity

The customer cannot find your old invoices

Imagine a customer moves to a new finance system and creates a new vendor record for your business. Current invoices appear under the new record, while earlier approved invoices remain under an old code that the accounts contact no longer checks.

Identify the record split before resubmitting everything. The problem may concern where the customer is looking rather than whether your business originally submitted the invoices correctly.

Confirm the business identity and codes

Ask the authorised accounts contact to identify the old and new vendor references. Check that the legal business details match and establish which record is intended for future submissions.

Do not assume a new vendor code changes the contracting party or the underlying debt. If the customer says the legal arrangement itself changed, obtain the relevant documents and advice where required.

Reconcile invoices across both records

Prepare a short schedule of outstanding invoices, original submission references and known approval status. Ask the customer to identify duplicates, migrated items and records still awaiting transfer or review.

Keep your own ledger tied to the actual invoices. A second customer-system entry should not automatically become a second receivable in your books.

Agree how missing items will be handled

If resubmission is required, obtain clear instructions and reference the original invoice and history. business.gov.au's invoicing guidance recommends clear invoice details and the information customers need to process payment.

Avoid issuing a fresh invoice number merely to make an old item appear new without checking the proper treatment. Ask the bookkeeper to confirm any necessary correction and preserve the audit trail.

Source: business.gov.au: How to invoice

Protect approval and payment information

Confirm whether earlier approvals remain visible and what action is still needed. Keep bank-detail verification separate from the vendor-code discussion, particularly if the migration request includes a change to payment instructions.

Use established contacts and authorised processes. A legitimate system change should not become a reason to abandon the controls used for sensitive account information.

Close the migration discrepancy

Obtain a reconciled list showing where each outstanding invoice sits and the next payment or approval action. Check the first resulting remittance against that list.

For future customer system changes, record vendor references and retain submission evidence before the transition. A clear link between the old and new records helps prevent existing approvals and unpaid balances from disappearing between systems.