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AI invoice coding: from a proposed entry to the ledger
Short answer
A model that names an account and an amount has prepared a proposed entry. An entry in the books needs a check of the source document, the agreed rules and control of the whole workflow, which Articles 20, 21 and 24 of Poland's Accounting Act describe. The accountant approves the proposal. At Syntalith the automation costs from €3,000 net, and with 1,000 cost invoices a month at 3 minutes each it pays back in 2.3 months.
How we workDetails ↓
- 01Call30 minutes with an engineer, free
- 02PrototypeA working system on your process and data, free
- 03ImplementationTarget and fixed price in the contract; 50% at signing
- 04Acceptance50% once the agreed target is met
- analysis with an engineer and a free prototype
- €0
- team in ChatGPT or Claude, up to 10 people
- from €1,150
- automation, agent or application for one process
- from €3,000
We belong to the OpenAI and Anthropic partner programmes and learn through their official courses. What this means ↓
Author: Syntalith · 3 min read
Statistics
Accounting and AI: statistics 2026
2.3 mo.
payback of a €3,000 automation at 1,000 cost invoices a month: €1,745 of work today, €444 with checking and the model. Scenario.
1 February 2026
According to Poland's Ministry of Finance (2026), all companies in Poland have received invoices through KSeF since 1 February 2026.
−87%
According to Anthropic (2025), AI cuts the time of a task on invoices, memos and other documents by an estimated 87%.
Source: Anthropic, Estimating AI productivity gains (2025) ↗
14–56%
According to Anthropic (2025), studies with a control group found smaller time savings, from 14% to 56%.
Source: Anthropic, Estimating AI productivity gains (2025) ↗
30.7%
According to Eurostat (2025), 30.7% of EU companies paid for cloud software for finance and accounting.
Source: Eurostat, digital economy and society statistics, enterprises (2025) ↗
Figures checked: 22 October 2026
AI invoice coding: a similar invoice, a different treatment
The same supplier issues invoices for two different services: machine servicing and staff training. The model proposes the account used for the previous invoice, because the supplier's name matches. A similar name does not settle the accounting treatment, and an accountant who approves the proposal without opening the description will book the training as servicing.
The proposed view shows the fields read, the document and the basis for the suggestion: which earlier invoice the model judged similar and why. When the description does not settle the treatment, the gap becomes a question for the accounts team. In Poland, Article 20(5) of the Accounting Act sets the conditions for computer records to count as equivalent to source documents, Article 21 describes checking a document and qualifying it for entry in the books, and Article 24 requires the books to be reliable, verifiable and kept up to date. The responsibility of the head of the entity under Article 4(5) stays when the books are entrusted to another person.
- 01Documentan invoice from KSeF or a PDF with a source identifier
- 02Proposalaccount, amount and the basis for the suggestion
- 03Checkthe accountant approves or corrects, with a reason
- 04Entrythe accepted entry in the system with the rules version
- 05Correctiona new document linked to the original entry
The test covers the path from the document to the entry in the system: a repeated document, a correction and an interruption after the data is passed on. A retry does not create a second entry without a check.
What automated invoice coding costs and when it pays back
- Today
- 1,000 cost invoices × 3 min = 50 h (€1,745)
- With the system, a person checks the output in 25% of the time
- €436
- Model, 1 call per case, Claude Sonnet 5.5
- €8
- Cost of one case
- €1.75 today, €0.44 with the system
- Saving
- €1,301 a month
Payback of €3,000
2.3 months
The volume, the time and the checking share are the scenario's assumptions. €34.90 an hour is the EU average hourly labour cost for 2025 according to Eurostat. Model: 3,000 input tokens and 300 output tokens per call at Anthropic's rates, converted at the ECB rate of 1.1205 USD per euro on 22 October 2026.
The count covers the work around each case: searching, reading, writing and handing over. What remains is the time to check the result, 25% of today's work in the scenario. Before the quote we measure both times on 20 to 100 cases the team has already handled, in a free test that takes 5 working days.
In this process the most expensive mistake is one approved without reading. So in the test we count the proposals the accountant corrected and those where the model flagged uncertainty. If there are more corrections than with manual coding, the scope goes back to the rules.
Where the project ends
Before you order, settle whether the project ends at a proposal, prepares an import or makes the entry. These options need different controls and access. The safest start is a proposal with its basis and the accountant's approval. Our invoice coding demo shows the mechanism of a proposal with a cited precedent.
Regular suppliers, one treatment
coding rules in the system
configuration
Proposals for the accountant to approve
an automation of proposals with their basis
from €3,000
Import or entry with no retyping
an integration with workflow control
priced after the review
Where to start
We run the first test on invoices from a closed month and compare the proposals with the entries the accounts team accepted. We build this kind of system as part of our AI automations. For the free process review, a description of one case from the last few weeks and the tools it went through is enough. You do not need to send confidential documents, and you receive a written plan within 2 working days.
Worked example · Scenario
How we count the payback: cost invoices
We run the same count for your invoices in the free process review.
€1,745
a month for coding 1,000 cost invoices by hand
Payback: 2 mo.
3 minutes per invoice and checking in 15% of the old time are our assumptions. €34.90 an hour is the EU average hourly labour cost for 2025 according to Eurostat, for companies with 10 or more employees. We measured the model cost of €0.004 per invoice in our invoice coding system, converted at the ECB rate of 1.1205 USD per euro on 22 October 2026.
See the full calculation →