How to write an invoice: what to include

What every invoice should include

1. Your business name and contact details, so the customer knows who to pay and who to call.
2. The customer’s name, and their address or email if you have it.
3. A unique invoice number, such as INV-0001.
4. The date you issued it and the date payment is due.
5. Each item or service on its own line, with a clear description, the quantity, and the price.
6. The subtotal, any tax shown separately, and the total amount due.
7. The currency, written clearly. This matters if you invoice in both Naira and dollars.
8. How to pay: your bank account details, or a payment link.
9. Any terms or notes, such as a late-payment policy or a thank-you.

How to number invoices

Number invoices in order and never reuse a number. Sequential numbers make it easy to find an invoice later, to see at a glance how many you have sent, and to spot one that has gone missing.

Decide the format once and stay with it. A prefix and a running number, like INV-0001, INV-0002, is enough. In KudiBooks the number is assigned when you create the invoice, so a draft you abandon never uses one up.

Showing tax

If you charge VAT, show it on its own line so your customer can see the rate and the amount. Mixing it into the price makes the invoice harder to read and harder to reconcile later.

Whether you must register for and charge VAT depends on your business and what you sell. Check the current rules with your accountant or the tax authority rather than relying on a general guide.

Say how and when to pay

Vague terms get paid late. “Payment due within 14 days” is better than “payment on receipt”, and a specific due date is better still. Put your account name, number and bank on the invoice, or include a payment link so the customer can pay without messaging you for details.

Mistakes that delay payment

• Vague descriptions. “Services” invites questions. “Logo design, 3 concepts” does not.
• No due date, which leaves the customer deciding when to pay.
• Missing a reference the customer’s finance team needs, such as a purchase order number.
• The wrong customer name or the wrong contact, so it never reaches the right person.
• Changing the total after you have sent it. Issue a corrected invoice instead and say which one it replaces.

Make the next one faster

Most of the time goes on retyping the same descriptions and prices. A tool that remembers your items turns a repeat invoice into mostly choosing, not typing. That is what saved items in KudiBooks are for.

Questions