The accounts payable invoice approval process is short to describe and slow to run, and the reason is that its longest step is performed by somebody outside the finance team who has no target attached to it. Understanding which step is which, and how long each actually takes in your own team, tells you whether your problem is process design or simply somebody not opening their email.
The four steps
Establish that the invoice is genuine and is ours. Match it against the purchase order and the goods receipt where those exist. Route it to whoever has authority for that value and cost centre. Record the approval with the name, the date and the amount approved. Only the third step involves waiting, and it usually accounts for the overwhelming majority of elapsed time.
Why the wait happens
The approver does not work for payables, has other priorities, and often receives the request as one more email among many. Add absence with no delegate and the tail gets long. None of that is fixed by a better form: it is fixed by routing to the right person first time, by delegation during absence, and by reminders that escalate rather than repeat.
What the record has to contain
Who approved, when, for what amount, and against which documents. That is what an auditor asks for and what a duplicate payment argument turns on. Approval by email reply is a record of a kind, but it is one held in a personal mailbox that may not exist in two years, which is a poor place for a control to live.
Questions people ask about accounts payable invoice approval process
Should an invoice with a matched purchase order still need approval?
Many organisations treat a clean three-way match within tolerance as sufficient authorisation, because the approval already happened at the order stage. That is a policy decision to make deliberately rather than by default.
How many approvers should an invoice need?
As few as your policy allows. Each additional approver adds elapsed time and diffuses responsibility, and two people each assuming the other checked is a common failure.
What is a reasonable approval time?
Measure your own distribution rather than chasing a benchmark. The long tail is where the cost is, and it is usually caused by a handful of identifiable situations.