Payment reminders

Payment reminder to a client in Belgium: 3 English templates

Your business is in Germany or Austria, your client is in Belgium, and the invoice is still open? Here are three English reminders ready to copy: payment reminder, second reminder and final notice, with euro amounts, the Belgian VAT ID and your bank details in the right place.

Wrong country? Pick your client's country here.

Payment reminder to a client in Belgium: 3 English templates
Published
Updated
Reading time
4 min read
On this page
  1. Your law, your interest
  2. The three templates
  3. What is different with clients in Belgium
  4. How Backbone does it
  5. Frequently asked questions

Your law, your interest

Your contract is usually governed by your German or Austrian law; best to state that in your quote and your terms. For business clients, German law gives you 9 percentage points above the base rate, so 10.52% for the second half of 2026, plus a EUR 40 flat fee. Austrian law gives you 9.2 points, so 10.73%, also with EUR 40. The late-payment interest calculator works out the exact amount.

The three templates

Pick where your business is based, Germany or Austria, above each template: the rate, the law and the flat fee are already filled in. You only replace the bracketed placeholders.

Stage 1: Payment reminder
Subject: Payment reminder — invoice [number]

Dear [Mr/Ms surname],

I hope you are well. This is a friendly reminder that invoice [number] of [invoice date] for EUR [amount] was due on [due date] and is still open on our side.

If the payment is already on its way, please disregard this message. Otherwise, please transfer the amount by SEPA credit transfer to:

Account holder: [your company]
IBAN: [IBAN]
BIC: [BIC]
Reference: [invoice number]

Your VAT ID: BE[0999999999]
VAT: reverse charge (services), VAT to be accounted for by the recipient

Kind regards,
[your name]
Stage 2: Second reminder
Subject: Second reminder — invoice [number], now overdue

Dear [Mr/Ms surname],

Despite our reminder of [date], invoice [number] of [invoice date] for EUR [amount] remains unpaid. The payment is now [x] days overdue.

Please settle the outstanding amount by [new date]. Under our terms and German law (§ 288 BGB), default interest of 10.52% per annum applies from [date default began], plus a flat fee of EUR 40 for recovery costs.

IBAN: [IBAN] · BIC: [BIC] · Reference: [invoice number]

If there is a problem with this invoice, please contact me directly so we can sort it out.

Kind regards,
[your name]
Stage 3: Final notice
Subject: Final notice — invoice [number]

Dear [Mr/Ms surname],

Invoice [number] of [invoice date] for EUR [amount] is still outstanding despite two reminders, most recently on [date].

Outstanding amount:                    EUR [amount]
Default interest ([x] days at 10.52%): EUR [interest]
Flat fee for recovery costs:           EUR 40.00
Total now due:                         EUR [total]

Please transfer the total to IBAN [IBAN] by [date]. If we have not received payment by then, we will hand the claim over for collection, and any further costs will be added to your account.

Kind regards,
[your name]

What is different with clients in Belgium

  • 60 days is a hard limit. In Belgium, payment terms between businesses may never exceed 60 days, not even if both sides sign. A longer term counts as not agreed. Without an agreement, 30 days from receipt of the invoice apply.
  • Review time counts. If your client has an acceptance or review period, it runs inside the 60 days. "We are still checking" does not extend the payment term.
  • Three national languages, one reminder language. Belgium speaks Dutch, French and German. In English you don't have to guess which one your client prefers, and every accounts team understands you.
  • VAT ID starting with BE. The Belgian number is BE plus ten digits, the first being a 0 or 1. It is also your client's company number, so it appears on their invoices and website.
  • Euro, SEPA and summer holidays. No exchange rate, no foreign transfer fee, and the SEPA transfer arrives by the next business day at the latest. July and August are the long school holidays in Belgium. If the deadline falls then, send the reminder at the end of June.

Why this one matters to us

My goal is to optimise and automate back-office tasks so that we founders can focus on what matters most.

Automating back-office work with AI agents and AI integrations is the future – that's why I built Backbone!

LucaLucaFounder, Backbone

How Backbone does it

Dunning on autopilot. In the app, or in a chat with ChatGPT, Claude and many more.

  1. Switch on dunning

    Set it once. Runs by itself.

    In the chat

    Switch on dunning: first reminder after 7 days, then 14 and 28.

    Backbone connectorupdate_reminder_settings

    Automatic reminders are on.

    • Payment reminder after 7 days
    • 1st notice after 14 days
    • 2nd notice after 28 days
    In the app

  2. Who's overdue?

    One question, every open invoice.

    In the chat

    Which invoices are overdue?

    Backbone connectorlist_dunning
    Overdue
    3
    Nordlicht GmbH
    RE-2026-0118 · 21 days
    €4,280.00
    Kinetik Studio
    RE-2026-0124 · 9 days
    €1,190.00
    Fernweh Reisen
    RE-2026-0131 · 4 days
    €942.50
    Total€6,412.50

    Nordlicht has been open the longest.

    In the app

  3. Send the reminder

    You approve. Only then does it go out.

    In the chat

    Send Nordlicht the 2nd notice now, not on the 25th.

    Backbone connectorsend_reminder
    Send reminder
    Invoice RE-2026-0118 · Due 27/09/2026
    2nd noticeDE
    To
    Nordlicht GmbH[email protected]
    Outstanding€4,280.00Late interest 10.52% · 21 days€25.91Flat fee€40.00Total€4,345.91
    Expires in 28 min28 min
    In the app
  • Automatic dunningLive
  • ChatGPT, Claude and many moreLive
  • Cards in the chatLive

More on dunning

Frequently asked questions

Can I send a client in Belgium a payment reminder in English?

Yes. Belgium has three official languages, but English is common in business. What matters is that the reminder is clear: invoice number, amount in euros, deadline and bank details.

How much interest can I charge?

Under German law 10.52% a year, under Austrian law 10.73%. On top comes a EUR 40 flat fee (as of the second half of 2026). If your contract uses your client's law, their rules apply.

How long can payment terms be in Belgium?

60 days at most, even if your client wants more. If nothing was agreed, 30 days from receipt of the invoice apply.

Where do I find my client's VAT ID?

It is BE plus their ten-digit company number, and it appears on their invoices and website. The EU's VIES portal tells you in seconds whether it is valid.

Ready to try it?

Try Backbone for 7 days. No charge before the trial ends.

Try for 7 daysSign in

General information, not legal or tax advice and no review of your case. Details on providers and laws can change. For your case, follow your tax adviser.

Sources: Wet van 2 augustus 2002 (betalingsachterstand bij handelstransacties), Art. 4 · § 288 BGB · § 456 and § 458 UGB · Deutsche Bundesbank (base rate) · OeNB (base rate) · Directive 2011/7/EU

Related articles

All articles