How to make an invoice (and get paid faster)

An invoice is a simple thing: a note that says what you sold, how much it costs and when the money is due. But a good invoice does more than that. It makes you look professional, it removes confusion, and it gets you paid sooner.

A bad invoice does the opposite. A missing due date gives the customer no reason to hurry. A vague line like "work done" invites questions. A total with no way to pay means another round of "please send your account details".

This guide shows you how to make an invoice step by step, what every invoice needs, and the small habits that help freelancers, shops and service businesses get paid faster.

What is an invoice?

An invoice is a request for payment for goods or services you have already agreed to provide. It is also a record. You and your customer can both look back at it to see what was bought, on what date, and whether it was paid.

An invoice is different from a quote. A quote is a price offer before the customer says yes. An invoice is the bill once they have agreed. Many small businesses send a quote first, then turn it into an invoice when the customer confirms.

What to put on an invoice

Every invoice should have these parts:

1. Your business name and contact details. Name, phone or WhatsApp number, email, and your logo if you have one.
2. The word "Invoice" and an invoice number. More on numbering below.
3. The date you issued it.
4. The customer's name and, if useful, their email, phone and address.
5. A list of what they're paying for. One line per item, with the quantity and the price of each.
6. Discounts, tax and delivery, each on its own line so the customer can see how the total was worked out.
7. The total, in big, clear numbers, with the currency.
8. The due date. Not "soon", not "ASAP": a real date.
9. How to pay. Your bank details, a payment link, or both.
10. A short note. A thank-you, or your terms in one or two lines.

Write lines people understand

"Design work: ₦150,000" makes people ask questions. "Logo design, 3 concepts and 2 rounds of changes: ₦150,000" doesn't. The clearer each line is, the fewer reasons a customer has to delay.

How to number your invoices

Give every invoice its own number and never reuse one. A simple pattern works best:

• INV-0001, INV-0002, INV-0003… in the order you send them
• Quotes can have their own series: QUO-0001, QUO-0002…

Numbers make it easy to find an invoice later, to match a payment to the right bill, and to keep your records tidy for tax time. If a customer says "I paid", you can ask "for which invoice?" and get a clear answer.

Due dates and payment terms

Payment terms tell the customer when and how they should pay. Common ones:

• Due on receipt. Pay now. Good for small jobs and products.
• Net 7 or Net 14. Pay within 7 or 14 days of the invoice date. Common for freelancers.
• Net 30. Pay within 30 days. Common with bigger companies.

Shorter terms usually mean faster money. If you are a small business, there is nothing wrong with asking for payment within 7 days. Put the actual date on the invoice too ("Due: 14 November"), because people remember dates better than "Net 14".

Ask for a deposit on big jobs

For custom orders, events, catering, tailoring or design projects, ask for a deposit before you start. Fifty percent up front is common. It protects you if the customer changes their mind, and it covers your costs for materials.

Make the deposit clear on the invoice: the full amount, the deposit due now, and the balance due on delivery or on a date.

How to send an invoice

Send it where your customer already is:

• WhatsApp. Fast, personal and read quickly. Send a picture or a link with a short, friendly message.
• Email. Better for companies and anyone who needs a record for their accounts.
• PDF. Some customers need a file to forward to their finance team.
• A link. One link that opens the invoice on any phone, ideally with a way to pay right there.

Whatever you use, write a short message with it:

"Hi Ada, here's your invoice INV-0012 for the 40 branded cupcakes, ₦64,000, due Friday 14 November. You can pay with the link. Thank you!"

How to follow up without feeling awkward

Most late payments are not bad intentions. People forget. A polite reminder fixes most of them.

A simple reminder rhythm:

1. The day before it's due: a friendly heads-up.
2. On the due date: "Just a reminder that invoice INV-0012 is due today."
3. A few days late: a calm, firm message with the link again.

Keep it short and kind. Always include the invoice number, the amount and the way to pay, so the customer can act in one tap.

Get paid faster: 7 habits that work

• Invoice right away. Send it the same day you deliver, while the customer is happy.
• Make paying easy. A Pay button or link beats "send me a screenshot of the transfer".
• Offer more than one way to pay. Card, bank transfer and mobile money cover most people.
• Use short terms. Seven days, not thirty, unless the customer really needs longer.
• Take deposits on big jobs. Never do all the work before seeing any money.
• Look professional. A clean design tells the customer you are serious.
• Track every invoice. Know who has opened it, who has paid and who is late.

How to make invoices on Klaasi

Doing all of the above by hand, in a notes app or a spreadsheet, gets tiring fast. Klaasi has invoices built in, so you can make one in a minute from your phone. See the invoice generator for a quick tour.

Write it in a minute

Add your customer, the lines, any discount, tax, delivery and the due date. Invoices are numbered for you (INV-0001, INV-0002…), and quotes get their own numbers (QUO-0001…).

Or type one sentence, the way you'd say it, such as "2 bottles of oud at 45,000 each and gift wrap 2,000 for Bola, due Friday", and Klaasi AI fills in the lines for you to check.

Pick a design

There are five designs: Classic, Minimal, Bold, Maison and Modern card. Free uses Classic, Pro adds Minimal, and Business has all five.

Send it anywhere

One tap opens WhatsApp with the message written for you and the invoice link. You can also email it, copy the link, download a PDF, or save it as a picture for chats and Status.

Add a Pay button (or don't)

This is your choice on every invoice:

• Pay button off: a plain invoice. Write your own bank details or "pay on delivery", and mark it paid when the money arrives. No Klaasi fee.
• Pay button on: your customer pays by card, bank transfer, mobile money or crypto. The money goes to your Klaasi wallet and the invoice turns Paid by itself. Klaasi's normal sale fee applies to these payments only.

With the Pay button on, you also choose who pays Klaasi's fee: you, your customer, or half each. And you can let the customer pay 50% first and the rest later.

See where every invoice stands

Each invoice shows a clear status: Draft, Sent, Viewed, Part-paid, Paid or Overdue. You can see when your customer opened it. Klaasi emails reminders for you the day before it's due, on the day and 3 days late, as long as you added the customer's email.

Quotes and repeating invoices

Send a quote first, and when the customer agrees, turn it into an invoice in one tap. On the Business plan, invoices can repeat every week or every month for regular customers.

How many invoices you get

The Free plan includes 3 invoices a month. Pro includes 200 a month, and Business has no limit. See the pricing page for plan prices.

Frequently asked questions

What is the difference between an invoice and a receipt?

An invoice asks for payment. A receipt confirms that payment was made. Once an invoice is paid, it becomes your record that the money came in.

Do I need to register a business to send an invoice?

In most places you can send an invoice as an individual or freelancer. Tax rules differ by country, so check what applies to you if you charge VAT or sales tax.

What should I do if a customer doesn't pay?

Send polite reminders first: before the due date, on the day, and a few days late. If that fails, call them, agree a new date in writing, and for future jobs ask for a deposit before you start.

Can I send an invoice on WhatsApp?

Yes. Send a picture or a link with a short message. On Klaasi, one tap opens WhatsApp with the message and the invoice link ready to send.

Is it free to make invoices on Klaasi?

Yes. The Free plan includes 3 invoices a month. Invoices without a Pay button have no Klaasi fee.

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Ready to send your first invoice? Start free on Klaasi, make an invoice in a minute and send it on WhatsApp today.