Invoice automation for an accounting firm: a complete guide

An accounting firm with 15 active clients processes between 800 and 2000 invoices a month. Entering each one by hand into the accounting software eats 30 to 50 hours monthly. Invoice automation for an accounting firm cuts that down to minutes: AI reads the attached PDF, recognises the supplier, amount, VAT and date, and writes the document straight into Microinvest or Ajur. Here is how it works in practice, where the traps are, and when the investment pays back.

Where the time goes today

Before automating anything, look honestly at the manual flow. At most firms an invoice goes through the same steps, each costing seconds, but multiplied by thousands of documents it turns into days of work.

• Downloading the PDF from email or a client folder in Google Drive.
• Reading off the supplier, date, base, VAT and total.
• Entering the document into Microinvest Delta Pro or Ajur.
• Checking the VAT number and reconciling the amounts.
• Renaming and archiving the file for the audit trail.

None of these steps needs accounting expertise. That is exactly why it is the first candidate for automation: high volume, low cognitive load, clear rules.

How AI invoice automation works

The modern approach is not template OCR that breaks on a new layout. AI reads the document in context, the way a person does, so it handles dozens of different suppliers without a separate template for each. The flow looks like this:

1. The system watches the inbox or the folder where invoices land.
2. OCR and a language model extract the fields: supplier, company ID, VAT number, date, base, VAT, currency, document number.
3. The data is checked against the tax register by company ID and against control sums (base plus VAT equals total).
4. The document is written into the accounting software through an import file or a direct connection.
5. When confidence is low, the document is flagged for human review rather than written in blindly.

Integration with Bulgarian accounting software

A firm rarely changes its accounting system because of automation, and it does not need to. We connect to what you already run:

• Microinvest Delta Pro — the most common case at firms. Import of documents and stock operations through a standard file format.
• Ajur — widely used at larger firms; supports structured import of primary documents.
• Konto 6 — popular with small firms; integration goes through file exchange.
• Plus Minus — common at the micro-companies a firm services on retainer.

The right path depends on the version and licence. With Delta Pro we usually start from an import file, because it is stable and does not depend on a special licence for programmatic access.

How accurate is OCR on Bulgarian invoices

On clean PDF invoices generated by software, extraction accuracy exceeds 98%. On phone photos and bad scans it drops, but control sums catch most errors before the write. Handwritten notes on the invoice do not get in the way, because the system reads the printed text, not the whole page indiscriminately.

What to expect realistically

Automation does not cover 100% of cases from day one, and we should not promise that. A few document types stay with a human at first:

• Credit and debit notes that tie back to an original invoice.
• Pro-forma invoices, which are not a posting document.
• Foreign-currency invoices that need the day rate.
• Documents with non-standard VAT regimes (reverse charge, margin schemes).

After a few weeks working with your real suppliers, the system covers a large share of these cases too. The goal is not to remove the person, but to take them out of routine entry and leave them on what needs judgement.

Return: when it is worth it

The maths is simple. A firm processing 1200 invoices a month at 2 minutes each spends about 40 hours of labour. At a rate of 15 euro an hour that is 600 euro a month, hidden in routine. Automation reduces manual work to reviewing the flagged cases, usually under 5 hours a month.

At a typical implementation price between 2000 and 4000 euro, the saved time returns the investment in three to five months. After that the saving is pure profit, or capacity for more clients without a new hire.

Frequently asked questions

Does this replace the accountant?

No. It replaces manual data entry, not accounting judgement. The accountant stops copying invoices and starts reviewing only the doubtful documents and working on things that bring the client more value.

How long does implementation take?

For a standard firm on Microinvest or Ajur, usually between two and four weeks. The first week we connect the systems and train the model on your real suppliers, then we run in parallel with the manual process until accuracy is confirmed.

Is my clients’ data safe?

Yes. We work under GDPR, sign an NDA before access, and for sensitive firms we offer processing on your own server, with data never leaving the country.

Does it work with invoices photographed on a phone?

It does, but with lower accuracy than a clean PDF. Control sums catch most errors from a bad scan and hand such documents to a quick human check instead of writing them in wrong.

Describe your invoice process in the chat on cresare.com and in under a minute you get a concrete plan: what gets automated, how it connects to Microinvest or Ajur, and a rough price estimate. No signup, no obligation.