Many organisations run an approval process that exists entirely as knowledge in the payables team: this invoice goes to that person, that supplier belongs to this department. It works, it is fragile, and it does not survive somebody leaving or the organisation reshaping. Writing the rule down is a morning of work and converts institutional memory into something that can be checked.
Base it on delegated authority you already have
Most organisations have a delegation of authority written for contracts or capital spend, and invoices usually fall under it implicitly. Starting there keeps the invoice rule consistent with everything else and makes it far easier to get agreed, since you are documenting an existing policy rather than proposing a new one.
Route by cost centre and value
Stable, matches how budgets are held, and answerable by the approver, who is being asked whether their budget should carry this. Supplier-based routing feels natural and ages badly, because suppliers move between departments and one supplier often serves several. Cost centre plus value survives reorganisations.
Name a destination for everything unusual
An unrecognised supplier, a closed cost centre, an invoice with no purchase order. Each needs a named person rather than a shared queue. These are the invoices that go missing, and they are also, occasionally, the ones that most deserve a second look.
Questions people ask about accounts payable approval process
Should two people approve large invoices?
Above a threshold many organisations require it. Be aware that dual approval can dilute responsibility, so it works best where both approvers have distinct reasons to look.
Can matched invoices skip approval?
Where a clean match within tolerance is treated as sufficient authorisation, yes. Write it down rather than letting it be a configuration default.
What about invoices from a supplier nobody recognises?
They should stop, not proceed. An unrecognised supplier is the shape of both an error and a fraud, and it deserves a person rather than a routing rule.