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AI agents for disputed invoice follow-ups

Short answer

When a client withholds payment until a complaint is resolved, an AI agent links the invoice with the client's message and the support ticket. The finance employee sees what the client is waiting for and gets a draft question for the person handling the complaint in place of another reminder. The agent costs from €3,000 net at Syntalith and, with 60 disputed cases a month at 60 minutes each, pays back in 2.1 months.

How we workDetails ↓

  1. 01Call30 minutes with an engineer, free
  2. 02PrototypeA working system on your process and data, free
  3. 03ImplementationTarget and fixed price in the contract; 50% at signing
  4. 04Acceptance50% once the agreed target is met
net per agent for one process, build paid once
from €3,000
from signing the contract to acceptance
6–16 weeks
free prototype on your cases
€0

We belong to the OpenAI and Anthropic partner programmes and learn through their official courses. What this means ↓

Author: Syntalith · 3 min read

Example: the morning request inbox
Agent · ready

Statistics

Receivables in EU companies: statistics 2026

2.1 mo.

payback of a €3,000 agent with 60 disputed cases a month: €2,094 of work today, €631 with checking and the model. Scenario.

Figures checked: 22 October 2026

What has to be clarified before the next contact

After the service was delivered, the client did not receive the agreed documentation. They filed a complaint and wrote that they are withholding payment of the invoice until it is resolved. Support is waiting for a document from the delivery team. Meanwhile finance sees an overdue invoice, and the next reminder ignores what the client wrote.

In a shared view, the employee sees the invoice next to the client's message and the ticket. The agent prepares a question for the person handling the complaint: has delivery already handed over the document, and if not, when will it? The answer completes the description of the case. Whether the client has received it remains the key point, because the internal explanation may be ready while the client is still waiting. The employee checks and sends the messages, and the assessment of the complaint and the handling of the receivable stay with the company.

A disputed case before the call
  1. 01Invoiceamount, due date and payment status
  2. 02Reasonthe client's message about withholding payment
  3. 03Complaintthe ticket and the person handling it
  4. 04Questiona draft to support about the state of the explanation
  5. 05Callfinance and the account manager know what to tell the client
What the agent does not do
  • It does not judge whether the complaint is justified
  • It sends no reminders on a case marked as disputed
  • It does not set settlement terms or agree a settlement
  • It does not contact the client without an employee's decision

What it costs and when it pays back

Scenario: 60 disputed cases a month
Today
60 disputed cases × 60 min = 60 h (€2,094)
With the system, a person checks the output in 30% of the time
€628
Model, 3 calls per case, Claude Sonnet 5.5
€3
Cost of one case
€34.90 today, €10.52 with the system
Saving
€1,463 a month

Payback of €3,000

2.1 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: 6,000 input and 700 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 a case: searching, reading, writing and passing things on. What remains is the time to check the output, 30% 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 €0 test that takes 5 working days.

According to the EU Payment Observatory (2025), 52% of European companies faced problems due to late payments in 2024. Some of these are disputed cases, where a reminder with no answer to the complaint only lengthens the time to payment.

Check what your finance system already shows

Ready-made finance systems often have a receivables view that links transactions, cases and activities. If the invoice shows a current ticket and it is clear who is resolving it, configuring the view or a rule that routes a disputed case to the responsible person is enough. The agent is useful when the information sits in free-form correspondence: the client writes an email, support answers in a separate thread, and finance has to understand what is missing. The article on receivables monitoring covers tracking due dates and reminders.

A view, a rule or an agent
  • The ticket sits on the invoice

    configuration of the receivables view

    no build

  • Disputed cases reach the wrong person

    a rule that routes disputed cases

    configuration

  • The reason for the dispute is in free-form correspondence

    an agent that links the invoice with the complaint

    from €3,000

Where to start

We start with one team and one type of service complaint. Usefulness shows in whether the person preparing the call understands why payment is being withheld. The team can also practise this work first in team AI training. We build this as part of AI agents. For the free process review, a description of one case from recent weeks and the tools it ran through is enough. You do not need to send confidential documents, and you get a written plan within 2 working days.

Worked example · Scenario

How we count the payback: receivables

We run the same count for your cases in the free process review.

€1,396

a month for preparing 300 receivable cases by hand

Payback: 2.5 mo.

8 minutes per case before a reminder 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. Model cost: 0.015652 USD per reminder draft with a separate tone check, measured in our receivables system, at the ECB rate of 1.1205 USD per euro on 22 October 2026. The payback counts saved time only. A reminder that goes out on time also recovers invoices that would otherwise go to an external agency or be written off, and we count that on your receivables during the review.

See the full calculation →

Client results.

All projects →
foap.comcustomer service

foap.com customer service: 95% of replies are sent automatically.

Users from several countries write to foap.com, in several languages. The system reads the entire conversation and the terms of that person, and then sends a response in that person's language. Questions about money and exceptions go to the team with a ready draft, so they have to check and send them.

the system sends the answers itself, without human typing
95%
time from the arrival of the e-mail to the ready response (median)
30 s
e-mails that require a response receive a ready-made draft
100%
less work for every 1000 answers (estimate)
47 h

Data from foap.com production, October 20-21, 2026. Estimate: 3 minutes for handwritten response.

How foap.com customer service works →
Sample messages. Money matters always come to the person.

Other implementations

jaktako.design

studio projektowe

−87%

Time to look for new customers, every day

4 hours → 30 min

approx. 73 hours less per month (21 days of work)

according to the studio

How the agent loop works →
Signature Estates

real estate

approx. −90%

Operator time spent browsing portals, per day

2–3 hours → 20 min

approx. 45 hours less per month (21 days of work)

respect · contact the seller 5 minutes after the announcement

How the agent finds property listings →
Kuba Koziej, CEO and co-founder of MoreGrowth and board member at Natu.Care

Kuba Koziej

CEO and co-founder, MoreGrowth

„We started with my own AI agent. During the training that followed, I learned to build new applications myself. Today I am bringing this way of working with AI into my business. Working with Syntalith gave me exactly the skills and tools I needed.”

View the original training review on LinkedIn ↗

See the agent on your own cases before you commit.Book a free process review (30 min) →

How we build automation and agents

From a conversation to a working system in four steps.

  1. 01 · 30 min

    Free process review

    €0

    You're talking to an engineer. You receive the written plan within 2 business days.

  2. 02 · 5 days

    Free prototype

    €0

    The system works on 20-100 cases that your team has already handled. You see every result.

  3. 03 · 2–16 weeks

    Build

    50%

    Fixed price and goal written in the contract. First installment upon signing.

  4. 04 · after reaching the goal

    Reception

    50%

    You pay the second installment when the system reaches its target on your cases.

How a free prototype is created

Mon.

We set a goal

What result do you consider good?

Tue–Wed

The system is working

It goes through your affairs, one by one.

Thu

We compare

We check every difference with the team's work.

Fri

Result and price

List of errors and fixed implementation price.

You choose the matters. We anonymize them upon request, they stay in the EU and we delete them after the test.

On the market, such a test usually costs from PLN 3,000 to PLN 8,000.

Book a free process review (30 min)

We establish a prototype during a free analysis.

Data checked on October 25, 2026.

„Is my data safe?”

Yes. You choose where they go: from your company account to the model on your server.

  1. 00Employee's private account

    Customer and company data ends up in an account that the company cannot see or control. There is no data processing agreement, so it is a violation of the GDPR. When an employee leaves, the chat history goes with them.

  2. 01ChatGPT or Claude corporate account

    The provider does not use your data to train models. A copy of the queries remains in his logs for up to 30 days.

  3. 02API with zero retention (ZDR)

    The provider processes the request and does not save anything. It requires his consent, we prepare the application together.

  4. 03Processing in the EU

    Queries are counted and stored in Europe: OpenAI in the EU region, Claude via clouds with the EU region.

  5. 04Model at your place

    The open model runs on your server or in your cloud in the EU. The data does not go outside the company.

What we do with every implementation

  • Confidentiality agreement and data processing agreement before we receive any data.
  • You choose the cases for the prototype and we anonymize them upon request.
  • The data stays in the EU and we delete it after the test.
  • Corporate accounts with an administrator on your side.

When data cannot leave the company

The open model runs on your server or in your cloud in the EU. To choose from:

White-tailed eagle
Polish model, SpeakLeash and ACK Cyfronet AGH
PLLUM
Polish model, HIVE consortium commissioned by the Ministry of Digitization
Qwen
Alibaba
GLM
Zhipu AI
DeepSeek
DeepSeek

We select a model for the task and check it on your cases. We run it, tune it and maintain it.

Source: Bielik and PLLuM, ACK Cyfronet AGH ↗ · PLLuM, Ministry of Digitization ↗

Do you have a lot of your own data? We will fine-tune the small model.

  1. 1 Your examples
  2. 2 tuning
  3. 3 test on new cases
  4. 4 model at your place

When you have thousands of similar emails, documents or reports, we teach a small open model based on your examples. It works for you, responds quickly and costs less to maintain than a large model. We measure quality on issues that the model has not seen while learning.

Przemysław and Piotr did it in large programming and consulting companies. Artem did it before and does it today at Syntalith. It's about models on your own infrastructure, tuning and quality measurement.

You choose the protection level during the interview. We sign the data processing agreement before we see any data.Schedule a free analysis →

AI agents

See the agent on your own cases before you commit.

The agent takes the case through the next steps in your systems, and the actions take effect until the consent of the indicated person is obtained. A prototype for 20-100 cases that your team has already handled costs €0. We write down the purpose and test set in the contract.

See AI agents →
net per agent for one process, build paid once
from €3,000
from signing the contract to acceptance
6–16 weeks
free prototype on your cases
€0

Questions

  • How do you prepare a call about a disputed invoice?

    Link the invoice with the client's message about withholding payment and the support ticket, establish where the explanation stands and whether the client has received an answer. Only then does the contact respond to what the client wrote.

  • Should you send a reminder when the client has made a complaint?

    Better to establish the state of the complaint first. A reminder that ignores the stated reason makes the conversation worse. A disputed case should have its own path.

  • How much does such an agent cost?

    At Syntalith from €3,000 net. With 60 disputed cases a month at 60 minutes each, the payback is 2.1 months. We agree integrations and maintenance before the quote, and the model costs €3 a month.

Let's talk

Just write, call or choose a date.

We work fast because we hate corporate cotton wool. We don't have salespeople or managers to keep an eye on managers. You talk immediately to engineers who then build your system. We respect each other's time and yours too.

We will accept 3 more companies by the end of the year.

Mon–Fri 9:00–17:00 CET

What our OpenAI and Anthropic partnerships mean for you.

OpenAI makes ChatGPT and Anthropic makes Claude. We belong to the partnership programs of both companies, so we work with their tools every day and learn from the creators themselves.

OpenAI Select PartnerClaude Partner Network
01We will select a tool for the task
We implement both ChatGPT and Claude. We check both on your documents, and you choose the one that makes fewer corrections and saves more time.
02Knowledge straight from the creators
We learn from official OpenAI and Anthropic courses and materials. Your team learns about the features and settings that work today.
03Licenses without our margin
When we roll out ChatGPT, Claude or Copilot, you buy the licences directly from OpenAI, Anthropic or Microsoft and they invoice you. We add nothing to the licence.
04Certified engineers
On the team, we have an AWS certification in machine learning and an Anthropic certification in systems architecture on Claude.

Participation in programs does not mean that OpenAI or Anthropic endorses our services.