Short answer
Put your business name and the invoice number in the subject line. In the email, say what the invoice is for, the total, the due date and how to pay, and attach the invoice as a PDF. In the Netherlands you may email invoices once your customer agrees to digital invoices. In Belgium, invoices to Belgian VAT-registered businesses have been structured e-invoices, usually sent through Peppol, since January 1, 2026.
Your invoice is ready to go. A short, clear email makes sure it reaches the right person and shows at a glance what needs to be paid. Below are three templates you can copy, subject lines an accounts team can find again, the rules for emailing invoices in the Netherlands and Belgium, and a checklist before you hit send.
What to put in the email with your invoice
The email is a cover note. The required details, such as your VAT number, the invoice number and the VAT per rate, belong on the invoice itself. In the email, repeat only what your client needs to process and pay the invoice.
- What the invoice is for: the job, the delivery or the period.
- The invoice number and the total including VAT.
- The due date, as an actual date rather than "within 14 days".
- How to pay: your IBAN, the account name and the invoice number as the payment reference, or a payment link.
- The invoice as a PDF attachment, with the invoice number in the file name.
- Who to contact with questions.
A subject line the accounts team can find
Larger clients often receive invoices in a shared accounts payable inbox, where staff search by invoice number, supplier name or purchase order number. Put those details first in the subject line and skip openers such as "Please find attached".
Example subject lines
Invoice 2026-0042 from [business name] Invoice 2026-0042, PO [client purchase order number] Invoice 2026-0042: [project], September 2026
Template: email with an invoice to a business client
This text suits most business clients. Fill in the fields in square brackets and check that the amount and date match the invoice.
Invoice email to a business client
Subject: Invoice [invoice number] from [business name] Dear [name], Please find attached invoice [invoice number] for [work or delivery] in [period]. The total is €[amount] including VAT. Could you transfer the amount by [due date] to [IBAN] in the name of [business name], quoting [invoice number]? If you have any questions about the invoice, call me on [phone number] or reply to this email. Kind regards, [name] [business name]
Template: short email for a regular client
If you work for the same client regularly and they know how you invoice, a shorter email is fine. Always include the invoice number, the amount and the due date.
Short invoice email
Subject: Invoice [invoice number]: [project] Hi [name], Here is the invoice for [project] in [month]: €[amount] including VAT, due by [due date]. You can pay through the link in this email or transfer it to [IBAN] with [invoice number] as the reference. Thanks again, great working with you! Best, [name]
Template: first invoice to a new client
With a new client, you don’t yet know how they process invoices. Ask whether the email address is right and whether the invoice needs a purchase order number or reference. That keeps your invoice from bouncing back and your payment from stalling.
First invoice to a new client
Subject: Invoice [invoice number] from [business name] Dear [name], Thank you for the assignment. Attached is the invoice for [work or delivery], as agreed in [quote or engagement letter] of [date]. The total is €[amount] including VAT, due by [due date], payable to [IBAN] in the name of [business name], quoting [invoice number]. Should invoices go to a different email address, or do they need a purchase order number or reference? Let me know and I will update it. Kind regards, [name] [business name]
Can you email an invoice in the Netherlands and Belgium?
In the Netherlands, a PDF invoice sent by email is a digital invoice. Your client must agree to receive invoices that way, so settle it in your quote or engagement letter. Invoices to the Dutch central government must be e-invoices, for example through Peppol.
In Belgium, VAT-registered businesses established in Belgium have exchanged structured e-invoices with each other since January 1, 2026, usually through Peppol. A PDF by email is no longer enough for those invoices. It is still fine for consumers and for clients not established in Belgium.
In both countries, send the invoice by the 15th day of the month after the month in which you supplied the goods or services.
E-invoicing in the Netherlands: what applies now and from 2030
Check this before you hit send
In Factuur Simpel you send the invoice by email straight from the app, with a link to a payment page showing your bank details, or through Peppol. With Complete you set your own email texts and clients can pay through your own Mollie account. The app works in English; invoice PDFs use Dutch labels.
- The email address: many businesses want invoices sent to a dedicated accounts address.
- The attachment: a PDF, not a Word or Excel file your client can edit.
- The amount, invoice number and due date match between the email and the invoice.
- Your IBAN matches earlier invoices. If your account number changes, confirm it another way too: clients are rightly wary of fake invoices with new bank details.
Frequently asked questions
Should the invoice be in the email body or attached?
Attach it as a PDF. The email is a cover note; the required details belong on the invoice itself. A PDF keeps your layout and is harder to change than a Word or Excel file.
Does my client have to agree to invoices by email?
In the Netherlands, yes: your client must agree to receive digital invoices, so settle it in your quote or engagement letter. In Belgium, invoices to Belgian VAT-registered businesses must be structured e-invoices, usually through Peppol, rather than PDFs.
What should the subject line of an invoice email say?
Your business name and the invoice number, plus your client’s purchase order number or project if there is one. That lets the accounts team match your invoice to the right order quickly.
Can I include a payment link in the email?
Yes. With a payment link your client pays online without retyping your details. Also include your IBAN and the invoice number for clients who prefer a bank transfer.
Send invoices straight from your invoicing software
Create the invoice in Factuur Simpel and email it with a payment link, or send it through Peppol. Try it free for 30 days.
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