AI accounts payable automation: from inbox to approved invoice

Alexander Krastev · 2026-10-19

Accounts payable is the part of finance where small mistakes become real money: an invoice paid twice, a total typed wrong, a supplier's bank account quietly changed by a fraudster. AI accounts payable automation is worth it only if it catches those — not if it just types faster.

The flow, step by step

1. Capture. Supplier invoices arrive by e-mail. An agent watches the mailbox (IMAP or Microsoft 365), takes each new message once, and saves the attachments — without marking the mail as read.

2. Read. Each invoice — text PDF, scanned PDF or a phone photo — is read by an AI model that returns the fields you defined: supplier, invoice number, dates, VAT number, net, VAT, total, line items, IBAN.

3. Check. This is where AP automation earns its keep:

• The maths — line items against the total, VAT against the base.
• A changed IBAN — if the bank account differs from that supplier's last accepted invoice, the invoice is held. A swapped IBAN is the most common invoice fraud.
• Uncertain fields — the model marks what it could not read with confidence; those invoices wait for a person, with the doubtful field highlighted.
• New supplier, unusual amount — flagged, not passed through.
• Local rules — for Bulgarian invoices: VAT rates, company-ID and VAT-number format and a Commercial Register look-up.

4. Approve. Anything held lands on the dashboard for a person. Approval can be a step of its own: the run pauses until someone says yes.

5. Post. Approved invoices go to Excel or CSV, your database, your ERP through its API, or an e-mail with the report attached.

What it costs to run

Every run shows its own cost, priced on the model it actually used, and a monthly budget stops an agent when it is spent. With a local AI model on your own server there is no per-invoice fee at all.

Where the data lives

AP data is sensitive. AIK can run entirely on your own server with a local model, so invoices never leave your network. With a cloud model, personal data such as IBANs and e-mail addresses can be masked before the call.

Before you switch it on

Run it on a month of past invoices and compare with what your team entered by hand: which ones did it hold, and why? Compare two or three AI models on the same files — the cheapest model that reads your suppliers' invoices correctly is the right one.

More: AI invoice processing · invoice fraud: the swapped IBAN · invoices from PDF to Excel.