For freelancers, SMEs & accounting firms

Send yourWIK letter in 2 minutes

Upload your invoice and instantly receive a legally compliant 14-day payment demand letter. Fully automatically calculated and 100% compliant with the Dutch Collection Costs Act (WIK).

Start free with 3 WIK letters — no credit card required
TechSupply B.V.
Herengracht 182
1016 BR Amsterdam
Invoice
F2026-4837
J. de Vries
Keizersgracht 44
3011 GH Rotterdam
IT equipment delivery€ 892,50
Installation & configuration€ 245,00
Support package Q1 2026€ 110,00
VAT 21%€ 261,98
Total€ 1.509,48
Due date overdue
wikbriefversturen.nl
8 March 2026
14-DAY DEMAND LETTER
Statutory demand per art. 6:96 Dutch Civil Code
From
TechSupply B.V.
Herengracht 182 1016 BR Amsterdam
To
J. de Vries
Keizersgracht 44 3011 GH Rotterdam
WIK letter sent
J. de Vries — € 1.509,48
Outstanding amount€ 1.509,48
Sent
Delivered
Opened
WIK letter — sent instantly
1,000+
letters sent
200+
satisfied users
100%
WIK-compliant
< 2 min
per letter
Try it yourself

Upload an invoice and experience it yourself

No account needed. Upload your invoice and see your WIK letter within 10 seconds. Like what you see? Create a free account and download or send your first 3 letters for free.

Upload or drag an invoice

Have an unpaid invoice?

Upload it here and instantly see what your WIK letter looks like — fully formatted and legally correct. Free, no strings attached, your file is not stored.

PDF, PNG or JPG — max 10 MB

STEP 01

Upload your invoice

Drag your invoice into the upload field. PDF, photo, or scan — it doesn’t matter. Our AI reads all the data.

STEP 02

Review & confirm

View your WIK letter with the extracted data. Adjust if needed — collection costs are calculated automatically.

STEP 03

Send the letter

Send directly via our platform or download as PDF. With tracking you know if the debtor has opened the letter.

Who is wikbriefversturen.nl for?

Freelancers
Send professional demand letters without expensive lawyers.
SME owners
Handle multiple outstanding invoices at once, correctly.
Accountants
Send demand letters on behalf of your clients, error-free.
Proof of receipt

Better than registered mail

In legal proceedings, the court may ask whether you can prove that the debtor received your WIK letter. Registered mail costs € 11,- per letter and only proves that something was delivered — not that the content was read.

Every demand letter sent via wikbriefversturen.nl includes full email tracking. You can see in your dashboard in real time whether your demand letter was delivered and opened. Stronger proof than registered mail, at a fraction of the cost.

EXPENSIVE
Registered mail
€ 11,- per letter
Trip to the post office
2-5 business days
No read confirmation
RECOMMENDED
wikbriefversturen.nl
From € 1.93 per letter
Directly from your dashboard
Delivered in seconds
Read confirmation included
Live tracking
WIK letter to J. de Vries
Sent
Email dispatched
Delivered
Delivered to recipient
Opened
Read by debtor
Legally airtight

Every letter complies with the law

The Dutch Collection Costs Act (WIK) prescribes exactly what a demand letter must contain. Our letters always include the correct wording, the statutory 14-day payment term, and the accurate calculation of collection costs according to the BIK scale.

Correct 14-day term wording
BIK scale calculation automatic
Invoice files are not stored
GDPR-compliant processing
Payment demand
14-day demand letter
AIRTIGHT
14-day
Statutory term
BIK scale
Costs calculated
GDPR
Privacy compliant
WIK
Legally valid
Watch out

Common mistakes in a WIK letter

An incorrect demand letter is not legally valid. This means you cannot claim collection costs — even if the debtor does not pay.

01

Incorrect term wording

"Payment within 14 days" is not correct. The law literally requires: "within fourteen days after the day of receipt of this letter" (Dutch: "binnen veertien dagen na de dag van ontvangst van deze brief"). Courts have rejected claims due to this error.

Payment within 14 days
Within fourteen days after the day of receipt
02

Incorrect collection costs

The costs must be calculated exactly according to the BIK scale (statutory collection cost rates). An amount that is too high or too low makes the WIK letter invalid and costs you your claim.

€ 40 collection costs (arbitrary)
Exactly calculated per BIK scale
03

Combining amounts

You may not add the principal amount and collection costs together in the demand letter. The law requires that you list the outstanding invoice amount and the collection costs as separate amounts.

Total: € 1,434.63 to pay
Principal € 1,247.50 + collection costs € 187.13
04

No proof of delivery built up

In legal proceedings you must demonstrate that the debtor received the demand letter. Without documented proof of dispatch and receipt, you lose your right to collection costs.

Letter by post without tracking
Sent with proof of delivery
Prevent these mistakes automatically
Our AI reads your invoice and generates a legally correct WIK letter.
Try for free
Pricing

Simple, fair, no surprises

Punch card 10

€49one-time
10 WIK letters
€ 4.90 per letter
No commitments
Valid for 6 months
Buy
Popular

Monthly

€29/month
15 WIK letters /mo
€ 1.93 per letter
Cancel anytime
Client management
Priority support
Start now

Punch card 50

€149one-time
50 WIK letters
€ 2.98 per letter
No commitments
Valid for 12 months
Bulk discount
Buy

All prices exclude VAT. Create a free account and receive 3 WIK letters to try it out — no commitments.

Knowledge base

Discover more about debt collection

Guides, tools and articles to improve your debtor management.

FAQ

Frequently asked questions

A WIK letter — also called a 14-day payment demand letter — is a legally required demand letter under article 6:96(6) of the Dutch Civil Code (Dutch Collection Costs Act / "Wet Incassokosten"). You send this letter to a consumer who has not paid an invoice. In the letter, you give the client a final term of 14 days to pay the outstanding amount. Only after this term expires may you charge collection costs. Without a WIK letter, the collection costs are not enforceable.
You send a WIK letter after your payment reminder(s) have not been successful and before you engage a collection agency. The typical process is: invoice → payment reminder → WIK letter → debt collection. The WIK letter is legally required for claims against consumers (individuals). Without this demand letter, you cannot recover the collection costs from your debtor.
A regular payment demand or payment reminder is an informal letter asking the client to pay. A WIK letter is a formal, legally prescribed demand letter that meets the requirements of article 6:96 of the Dutch Civil Code. The difference: in a WIK letter you must explicitly state a payment term of at least 14 days and the exact amount of collection costs that will be owed if payment is not made on time. Read the full article →
Yes. Every letter created through wikbriefversturen.nl complies with all requirements of the Dutch Collection Costs Act (art. 6:96(6) Dutch Civil Code): the correct wording, a payment term of at least 14 days, the accurate calculation of collection costs according to the statutory scale, and statement of the total amount including collection costs. The collection costs are automatically calculated based on the amount of your claim.
The WIK letter is legally required for claims against consumers (individuals). For business clients (B2B), the 14-day demand letter is not legally required, but it is advisable to send a professional demand letter before starting a collection procedure. You can also use wikbriefversturen.nl for business debtors. The difference is that with business clients, you have more freedom in the amount of collection costs, provided it is reasonable.
You upload your invoice as a PDF, photo, or scan. Our AI system automatically extracts the key data: your company details (name, address, chamber of commerce number), the debtor's details, the invoice number, the invoice amount, and the due date. You can review all data and adjust if necessary before the WIK letter is generated.
No. After extracting the data, the uploaded file is automatically deleted from our servers. We only store the data needed to create the letter. Your data is processed in compliance with the GDPR (General Data Protection Regulation) and stored within the EU.
Yes. The law does not prescribe the delivery method for the demand letter. If you normally communicate with your client by email, email is a valid channel. You can send the letter directly via wikbriefversturen.nl by email — including proof of delivery — or download the letter as a PDF and send it yourself. Learn more about email delivery →
Yes. If a client has multiple outstanding invoices, you can combine them into one WIK letter. The system then automatically calculates the total principal amount and the corresponding collection costs on the combined amount. This is more efficient than sending a separate letter for each invoice.
The amount of collection costs is set by law in the Decree on Extrajudicial Collection Costs (BIK scale). The scale is as follows: 15% on the first € 2,500 (minimum € 40), 10% on the next € 2,500, 5% on the next € 5,000, 1% on the next € 190,000, and 0.5% on the amount above € 200,000 (maximum € 6,775). Calculate your collection costs →
That depends on your situation. If you are VAT-registered, you must charge 21% VAT on the collection costs. This VAT amount may be charged on top of the collection costs to your debtor. Are you exempt from VAT? Then you do not charge VAT on the collection costs. Wikbriefversturen.nl calculates the VAT automatically based on your settings. Learn more about VAT and collection costs →
If your debtor still has not paid after the 14-day term, you may increase the claim with the collection costs. You can then transfer the claim to a collection agency, collect the claim yourself through court proceedings, or arrange a payment plan with your debtor. Learn more about your options →
When creating an account, you receive 3 free letters, no credit card required. After that, you can buy a punch card (from € 2.98 per letter) or take a monthly plan for regular use. For comparison: registered mail costs € 11,- per letter and you have to go to the post office yourself.
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