Debtor reminders on autopilot means every overdue invoice gets a reminder on the right day, written from the invoice status and the customer's latest emails. Customers who promised payment, paid in part or raised a dispute get a different message or a person. DSO falls because each reminder asks for something the customer can act on.
At Lleverage we think the schedule is the easy part. Most ERPs can already send reminders on a schedule. What a credit controller does by hand is the reading before it: the email saying the payment went out on Friday, the short delivery queried in the purchasing inbox, the contact who left in June. A reminder sent without that reading costs goodwill and collects nothing.
We build AI agents for companies that make, move and sell physical products, and our accounts payable and receivables agents remind debtors the day an invoice falls due, in your tone, with the invoice attached and the last conversation remembered. Our earlier guide to accounts receivable automation software covers cash application and disputes; this post covers the reminder itself. To see it on your own open items, book a demo.
What are debtor reminders, and why do they still take so much time?
Debtor reminders are the messages a supplier sends when a customer invoice passes its due date: a friendly first notice, a firmer second one, then a final notice before a phone call or a collection agency. It is part of what Dutch finance teams call debiteurenbeheer, and in a mid-sized company it sits with 1 or 2 people in finance.
The sending takes minutes. The time goes into deciding what each reminder should say. A controller at a typical wholesaler opens the ageing list on Monday morning and works down it with the shared inbox open beside it. For each line they check whether the customer wrote in since the last notice, whether a payment arrived that nobody applied, whether sales promised a credit note, and whether the invoice went to the right address at all.
That check is why reminders slip. On a busy week the controller sends the batch unread, and a customer who paid on Thursday gets a second notice on Monday. On a quieter week the controller reads everything, and the batch goes out 4 days late. Both cost money: the first costs goodwill, the second costs days of cash.
How do debtor reminders affect DSO?
Days sales outstanding (DSO) is the average number of days between an invoice and the cash. The usual formula divides trade receivables by credit sales over a period and multiplies by the days in that period. Reminders act on the part of DSO that comes from invoices nobody followed up on time.
A worked example with invented figures: Brakveld Techniek, a parts distributor, invoices 18 million euros a year on credit and carries 2.4 million euros in receivables. Its DSO is 2.4 divided by 18, times 365: about 49 days on 30-day terms. Each day of DSO is worth about 49,000 euros of cash. Taking 5 days off frees about 247,000 euros, without a single price change.
Those days rarely come from customers who refuse to pay. They come from the reminder that went out a week late, the one that went to a buyer who no longer works there, and the one that asked for payment on an invoice the customer disputed in an email nobody linked to the account. Each of those adds days to DSO before a person even picks up the phone.
What does late payment look like in Europe in 2026?
Late payment is already past what many suppliers can carry. According to Intrum's European Payment Report 2026, a survey of 8,385 executives in 20 European countries, respondents say 12.13% of their revenue is paid late. The same respondents say 12.08% is the most they can absorb without it affecting how they operate. According to Intrum, 62% of businesses say these delays lead them to pay their own suppliers late, so a slow reminder at one company becomes a late payment at the next.
Intrum's report also finds that 66% of businesses now use AI in their payments management, up from 59% in 2025. Another 34% have started but are waiting to see results before using it more, and 34% use no AI tools in payments at all. For a finance team that means AI in payments is common, and the results are still being proven.
The law already sets the rules a reminder works within. Under the EU Late Payment Directive (2011/7/EU), which each member state wrote into its own law, a business-to-business payment term defaults to 30 days when the contract sets none. Contracts may agree up to 60 days, and longer only when that is not grossly unfair to the supplier. Once payment is late, the supplier is entitled to interest and a fixed sum of at least 40 euros, without the necessity of a reminder. A reminder is how you collect sooner. The right to that interest and fixed sum does not depend on it.
What does your ERP already do with debtor reminders?
Most ERPs run the reminder schedule well. Microsoft Dynamics 365 Business Central, for example, lets you set reminder terms with as many levels as you need. Each level carries its own grace period, fees, interest and email text per language, and a reminder automation can create, issue and send the reminders on a weekly, monthly or custom cadence.
That covers the rules a finance team can write down in advance: which customers get which terms, how long to wait, what fee to add. Business Central can also include invoices that are on hold, for example during a dispute, so the customer sees the full picture.
What a rule cannot write down is the content of the inbox. Its reminder automation works from the ledger and the reminder terms. It has no way to know that the customer emailed a remittance this morning, that their buyer asked for a copy of the proof of delivery, or that sales agreed a part payment on the phone. Somebody has to put those facts onto the account before the batch runs, and that somebody is the controller with the inbox open.
| Situation | Rule-based reminder in the ERP | AI agent reading invoice and inbox |
|---|---|---|
| Invoice overdue, no contact since | Sends the level 1 reminder on schedule | Sends the reminder in your tone, invoice attached |
| Customer emailed "paid on Friday" | Sends the reminder anyway unless someone sets a hold | Checks the bank lines, holds the reminder, flags it if no payment arrives |
| Customer disputes a delivery | Sends a reminder unless the entry is on hold | Hands it to credit control with the order, delivery and email gathered |
| Part payment received | Reminds for the full open item until cash is applied | Reminds for the remainder and names what it covers |
| Contact person left the company | Sends to the address on the customer card | Notices the bounce or reply and asks a person for the new contact |
| Long-standing customer, large amount | Same level 2 text as every account on those terms | Hands the account to a person for a phone call |
How does an AI agent prepare a payment reminder?
An AI agent prepares a payment reminder by reading the invoice status in the ERP, the incoming bank lines and the customer's recent correspondence together. It works out what the customer owes and what they last said, then writes the reminder or passes the account to a person. Each reminder carries that context.
In practice the agent works through the overdue list each morning:
- It reads the open items from the ERP: invoice, due date, amount, previous reminders.
- It checks the day's bank lines and any remittance email for payments not yet applied.
- It reads the customer's recent emails in the finance inbox for a promise to pay, a dispute, a request for a copy or a new contact.
- It writes the reminder in your tone and language, with the invoice attached, for every account where the facts are clear.
- It hands every other account to a person in credit control, with the history gathered on one screen.
The agent scores how sure it is of each piece of work. Below the line you set, a person decides; above it, the reminder goes out on its own, and only you move the line. Every action is written to an audit trail your controller can read. Releasing a payment is never the agent's call.
The rules your team keeps in their heads end up written down. One customer always pays on the 25th of the month and should never get a reminder before the 28th. Another wants every notice addressed to their accounts payable mailbox and copied to the buyer. A controller corrects the agent once, and the correction goes into the company brain for the next reminder to that account.
Which debtor reminders should go to a person?
Disputes, large balances, key accounts and anything the agent is unsure of should go to a person. A reminder is a message to a customer you want to keep, and some messages need judgement about the relationship that a ledger does not hold.
We set the hand-over rules with your credit controller in the first weeks. Typical ones:
- Any account where the customer's last email disputes a price, a quantity or a delivery.
- Any balance above an amount you choose, or any account on your list of key customers.
- A third reminder on the same invoice, where a phone call usually does more than another email.
- A customer who promised payment by a date that has now passed.
Everything handed over arrives with the reason, the open items, the last emails and the delivery documents attached. The controller makes the call and does not have to rebuild the account first. That is where most of the time goes today, and it is the time an agent gives back.
How do you roll out automated debtor reminders safely?
Start supervised. For the first weeks the agent drafts every reminder and a person approves the batch before anything goes out. You compare its drafts with what your controller would have sent, correct the ones that are wrong, and move reminder types to send on their own only when the drafts are right.
That order matters because reminders reach customers directly. A wrong reminder to a 40-year customer costs more than a late one. Cees Maaskant put it this way about the order agent at Xpol, which prepares drafts a person signs off:
"It’s a matter of building trust in the organisation with these kinds of initiatives. You can’t just throw something like this over the fence." Cees Maaskant, General Manager, Xpol
The sequence we use:
- Pick one entity and one reminder term, usually the standard 30-day customers.
- Let the agent draft the reminders for a few weeks while your team keeps sending its own, and compare the two.
- Go live supervised, with a person approving each morning's batch.
- Let first reminders on clear accounts go out on their own once the drafts are right week after week; keep disputes and key accounts with a person.
- Measure DSO and the share of reminders that led to payment within 7 days, month on month.
Our forward deployed engineers set this up with your finance team, inside the ERP you already run. Our integrations cover Business Central, SAP, Exact, AFAS, Infor and others, and nothing is migrated. The difference between supervised agents and background automation explains when a task is ready to move from one to the other.
Frequently asked questions
What should a debtor reminder contain?
A debtor reminder names the invoice number, invoice date, due date and the amount still open, and attaches the invoice. It says how to pay and who to contact with a question. Later reminders state the interest and fixed recovery sum the law allows. Keep the tone matched to the customer and the stage.
How many debtor reminders should you send before a phone call?
Usually 2 or 3. Business Central, for example, supports any number of reminder levels, and Microsoft notes most companies use only 2 or 3. A phone call usually follows the last written reminder. For a key account or a large balance, a person should call earlier, often after the first reminder goes unanswered.
Can automated debtor reminders damage customer relationships?
They can when they ignore what the customer already said: a reminder after a promise to pay, or during an open dispute, reads as careless. An agent that reads the inbox before each reminder avoids most of those cases, and hands disputes and key accounts to a person in credit control with the history gathered.
Do you need to send a reminder before charging late payment interest in the EU?
No. Under the EU Late Payment Directive, a supplier in a business-to-business sale is entitled to interest for late payment and a fixed sum of at least 40 euros without the necessity of a reminder. Many suppliers still send one first, because a reminder usually collects faster than a claim.
How quickly do automated debtor reminders reduce DSO?
The effect shows once reminders go out on time and to the right person, which in a supervised rollout takes a few weeks. How many days come off depends on your customers and terms. Measure DSO monthly against the months before, and track how many reminders lead to payment within 7 days.
Put your reminders on autopilot, with your team in control
Pull the last 3 months of reminders your team sent and count how many went to customers who had already paid, disputed or promised a date. That number is the work an agent takes off the desk. Our AI agents read the ledger and the inbox together and hand the judgement calls to your credit controller. Book a demo and we will run them on your own open items.