How to write an invoice, part by part

1. Say who the invoice is from

Your name or trading name, an address, and an email that you actually read. If you are registered for tax, your tax number belongs here too — many finance teams will not process an invoice without it. A logo is optional and changes nothing about whether you get paid; it just makes the document look like it came from a business rather than a text editor.

2. Say who it is to

Use the client's legal name, not the brand you know them by, and their billing address. If somebody specific approves your work, name them — invoices addressed to nobody sit in inboxes. If the client raised a purchase order, its number goes in its own field, because that is the first thing their system matches on.

3. Number it and date it

Every invoice needs a unique number, and the numbers should run in sequence with no gaps and no reuse: INV-0001, INV-0002. You need the issue date, and a due date written as an actual date. “Net 30” on its own is a term, not a deadline — write both if you like, but the date is what people act on.

4. Describe the work, one line at a time

A line per thing you did, with a quantity and a unit price. Describe it the way the client described it when they asked for it: “Website copy, 5 pages” beats “copywriting”. Hours and days go in the quantity column with your rate as the unit price, so the arithmetic is visible. Resist the single-line invoice for anything but the simplest job; a breakdown is what lets someone approve it without ringing you.

5. Total it honestly

Subtotal, then any discount, then tax, then the total, all in one currency. Show tax as its own row with the label and rate rather than folding it into your prices. If a deposit was already paid, list the full amount and take the deposit off as a discount with a note saying when it was paid — the client sees the whole job and what is still owed.

6. Tell them how to pay

Bank details, a UPI ID, or a payment link — whatever you accept, written plainly. In Invoira, typing them as “Label: value” lines makes them print as a neat table. Add your payment terms in a sentence. This is the part people leave off in a hurry, and it is the part that costs them a week.

Before you send: a checklist

• The invoice number is new and follows the last one.
• The client's legal name and the PO reference match their paperwork.
• The due date is a date, and it matches the terms you agreed.
• Every line has a description a stranger could understand.
• The currency is stated and the tax row shows its rate.
• Payment details are on the document, not only in the email.
• The file is a PDF with selectable text, named after the invoice number.
• It is going to the right address — accounts payable, not only your contact.

Mistakes that delay payment

• No PO reference when the client raised one: the invoice waits in a queue nobody is watching.
• Vague descriptions, so the approver cannot tell what they are approving.
• A reused or missing invoice number, which their system may reject outright.
• Terms with no date, leaving “when we get to it” as the deadline.
• Payment details missing, or different from the ones on your last invoice.
• A photo or screenshot instead of a PDF, which accounting software cannot read.
• Sending it late. An invoice sent the day the work finished is paid sooner than the same invoice sent three weeks later.

A worked example

Questions

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