Free tools for your business
Seven small, sharp tools for the jobs that come up in a shop.
Free · No sign-up · Nothing leaves your browser
- How do I make an invoice?
Invoice generator
Open→ - Where does my card fee end up?
Card fee calculator
Open→ - How much VAT is in this price?
VAT calculator
Open→ - Is this VAT number valid?
VAT number check
Open→ - What does this line on my statement mean?
Statement decoder
Open→ - Is this IBAN correct?
IBAN check
Open→ - I need a sign for the door
Shop signs
Open→
The longer explanations.
- Interchange, scheme, acquirer: who takes what?→ The three layers of a card fee, explained.
- Can you charge a fee for card payments?→ The rules, and why it is banned on consumer cards.
- What does a payment terminal cost?→ Prices and fees for 2026, plainly.
- All guides→ Practical guides to payments and running a shop.
About the tools.
Are they really free?
Yes, and there is no sign-up, no trial and no email wall. We build them because a merchant who understands what a card fee is made of is a better conversation than one who does not, and that is worth more to us than a lead capture.
Where does my data go?
For the calculators and the invoice generator, nowhere. Everything runs in your browser and nothing is sent to us. The VAT number check is the one exception: it queries VIES, the European Commission’s official register, because that lookup can only happen on their side.
Can I use the invoices commercially?
Yes. There is no watermark and no attribution required. It produces an ordinary invoice PDF that you own.
Do I have to be a SEJR customer?
No. None of the tools ask who you bank with or who processes your cards, and none of them behave differently if you are a customer.
Payments that read as clearly as the tools.
Card, MobilePay, Apple Pay and Google Pay, money in the account the next banking day, and a Danish adviser when you need one.
See SEJR Pay