Buyer's guide
Accounts payable software: how to choose it in Spain in 2026
Accounts payable (AP) software receives supplier invoices, extracts their data, compares them with the purchase order and the delivery note, routes them for approval and leaves them ready to post and pay in the ERP. When choosing one in 2026, what matters most is not how it reads the invoice but how it proves that what was invoiced is what was ordered and what arrived.
This guide is for finance directors, controllers and AP managers at mid-sized and large companies in Spain that receive thousands of invoices a month, often across several companies, buying against purchase orders with goods received on delivery notes.
Four kinds of tool competing for the same budget
| Kind | Does well | Leaves unsolved |
|---|---|---|
| Invoice capture / OCR | Reading the invoice into the ERP | Checking against PO and delivery note; approvals |
| ERP purchasing module | Posting and payment in one system | Line matching is done by a person, invoice by invoice |
| Global source-to-pay suite | Purchasing, catalogues, contracts, suppliers and payments together | Long project and high cost if you only need invoice control |
| Specialised invoice control (like ininvoice) | Line-level invoice–PO–delivery note matching, exceptions, approvals, several companies | Does not replace the ERP or make payments |
The question that matters most: lines or totals?
Comparing invoice total with order total looks sufficient and is not: two errors of opposite sign cancel out and the total matches. This constructed example shows it with two lines.
| Line | Order | Invoice | Price difference |
|---|---|---|---|
| Item A, 100 units | €12.40 = €1,240.00 | €12.90 = €1,290.00 | +€50.00 |
| Item B, 50 units | €8.00 = €400.00 | €7.00 = €350.00 | −€50.00 |
| Total (net) | €1,640.00 | €1,640.00 | €0.00 |
Price difference per line = (invoiced unit price − order unit price) × invoiced quantity. With ininvoice's default tolerance (€1.50 or 2 % per line; exceeding either one flags the line), both lines are flagged even though the total matches to the cent. The comparison always uses pre-tax prices.
Want to see it with your own invoices? Request a demo with your own invoices
Other criteria worth testing in a demo
- Partial deliveries: invoice 600 units against an order of 1,000 with only one delivery note of 400. What happens?
- Several companies: what happens to an invoice whose recipient tax ID belongs to none of your companies? See multi-entity.
- Approvals: if nobody has authority to approve an invoice, what does the system do? In ininvoice no invoice approves itself: a person approves, rejects or asks for clarification from the dashboard.
- E-invoicing: Spain's Royal Decree 238/2026 gives four calendar days, excluding weekends and national holidays, to report acceptance or rejection and payment (article 10.3). Accepting or rejecting requires matching first. ininvoice reads PDF and image today; structured e-invoice reading is in development.
- ERP: where do orders and delivery notes come from, and how does the checked invoice go back? In ininvoice, orders and delivery notes come in as documents, like the invoices, and validated invoices are exported as CSV or Excel importable into the ERP.
- Audit trail: who approved a difference, when and why, per invoice.
When you do not need AP software
If you receive a few hundred invoices a month and almost none carry a purchase order, good OCR connected to the ERP is usually enough. If your spend is mostly fixed recurring services, the useful control is the contract, not the delivery note.
ininvoice is built for large companies and groups. Related guides: how three-way matching works, reconciling invoices with delivery notes, working alongside SAP, working alongside Business Central, spotting duplicate supplier invoices and the AP cost calculator.
Frequently asked questions
What is the difference between AP software and invoice OCR?
OCR reads the invoice and passes its data to the ERP. Accounts payable software also checks that data against the purchase order and the delivery note, runs approvals and keeps a record of every decision before posting and payment.
Doesn't my ERP purchasing module already do three-way matching?
Many ERPs can link invoice, order and goods receipt, but leave the heavy work to a person: keying the invoice, deciding which line matches which and resolving each difference. Specialised software prepares that match and leaves only the exceptions to a person.
How does mandatory e-invoicing in Spain affect accounts payable?
From 6 October 2027, companies with a turnover above 8 million euros must receive e-invoices and report acceptance or rejection and payment within four calendar days, excluding Saturdays, Sundays and national holidays. Receiving an invoice electronically does not prove it matches what was ordered and received.
Can an invoice total match while its lines are wrong?
Yes. Two errors of opposite sign cancel out: an overcharge on one line and an undercharge of the same amount on another leave the total matching to the cent. That is why the check has to be line by line, at pre-tax unit prices.
How long does an implementation take?
Implementation time depends on the tool and on how purchase orders and delivery notes reach it from the ERP; always ask for the plan in writing with your real volume. ininvoice needs no implementation project or consultant: you start with one pilot company and its real documents.
Want to see it with your own invoices? Request a demo with your own invoices