A business case for AP automation is read by somebody whose job is to ask where the numbers came from. Ordering the benefits by how well each survives that question, rather than by how impressive each sounds, produces a case that gets approved. The first benefit is arithmetic; the rest are real and belong stated as capabilities rather than as invented sums.
Labour, which is arithmetic
Volume times minutes per invoice times fully loaded hourly cost, applied only to the share of invoices that can actually clear without a person. That last restriction is what makes the figure credible: claiming a saving on invoices that will still need somebody is the mistake that gets a case sent back.
Cycle time, stated as a capability
Shorter elapsed time from receipt to approval means terms can be met reliably, early settlement discounts become available where they exist, accruals are less speculative, and suppliers stop chasing. All real, none easily monetised without inventing something. Stated as capabilities gained, they strengthen the case; stated as dollars, they weaken it.
Control and record, stated as risk reduction
Duplicate prevention, an approval trail that survives a departure, visible exception ageing, and a defence against bank-detail fraud. These are insurance rather than savings. Putting them last is not a judgement about importance; it is a judgement about what a sceptical reader will accept without argument.
Questions people ask about ap automation benefits
Should we include soft benefits at all?
Yes, as capabilities. Inventing a value for an audit trail invites an argument about the invented number and distracts from the solid arithmetic.
How conservative should the labour figure be?
Apply it only up to your measured purchase-order and receipt coverage, since invoices with nothing to match against still need a person.
What if the case is marginal?
Then the free upstream improvements are your project, and they may make the software case later. Both outcomes are useful.