The nine things a complete invoice contains
There's no universal legal format for an invoice, but tax authorities in most countries — IRS, HMRC, CRA, ATO, the EU's VAT directive — converge on roughly the same nine items. If yours includes all of these, in plain English, you'll never have a client say "I can't process this."
1. The word "Invoice"
Top of the page. Title case. This sounds obvious, but more than once I've seen people send a PDF that looks like an invoice without ever using the word, and the document gets misfiled as a quote or estimate. Don't make a busy accounts payable clerk guess.
2. A unique invoice number
Every invoice needs its own number, and the sequence has to be unbroken. The reason is dull but important: tax authorities check that you can't hide an invoice by skipping its number. The simplest scheme is sequential: INV-0001, INV-0002, and so on. Some people prefix by year (2026-001) or by client (ACME-001). Both are fine as long as no number is ever reused or skipped. If you have to void an invoice, mark it VOID — don't reuse the number.
3. Your name and contact information
Your legal name (or registered business name), street address, email address, and phone number if you list one. If you operate as a registered company, include your company number and registered office. If your jurisdiction issues you a tax ID (VAT number, GST number, EIN, ABN), put it on every invoice. Missing tax IDs are one of the top reasons EU and UK clients legally refuse to pay.
4. The client's name and contact info
The full legal name of the company or person you're billing, their billing address, and ideally a specific contact name (the person who hired you, or their AP contact). Generic addresses like "Accounts Payable" or "Billing Department" cause delays — your invoice sits in a shared inbox.
If the goods or services were delivered to a different address, include a separate "Ship to" section. Many of our users need this for cross-border shipments where customs requires it.
5. Issue date and due date
The issue date is the date you're sending the invoice — not when the work was done. The due date is the calendar date payment is expected.
Do not write "Due in 30 days." Your client's billing software wants an absolute date. If your terms are Net 30 and the invoice issues on March 5, write "Due April 4." If you'd like to learn more about what Net X actually obligates, we have a separate guide on payment terms.
6. A purchase order or reference number, if applicable
For corporate clients, this is non-optional. Their AP system will reject any invoice missing the PO. Ask before you send — every PO has a number, and getting it on the invoice up front saves a two-week round-trip later.
7. An itemized list of what was sold
This is the part that actually determines how fast you get paid. For each line, include four columns:
- Description. Specific, scannable. "Logo design — 6 hours" beats "Design services." If you attached time to a project, name the project.
- Quantity. Hours, units, or just "1" for a flat-fee deliverable. Decimals are fine for partial hours.
- Rate. The per-unit price.
- Amount. Quantity × rate. Auto-calculated by any decent tool.
One uncomfortable truth: vague invoices invite negotiation. A client who can see what they're paying for line-by-line rarely disputes the total. A client looking at "Consulting services — $4,800" finds room to push back.
8. Subtotal, adjustments, total
Show your math:
- Subtotal (sum of line items)
- Discount, if any (percent or flat)
- Tax (with the rate clearly named — "VAT 20%", "Sales tax 8.25%")
- Shipping or expenses, if separately billed
- Total — larger font, the answer to "what do I owe?"
- Amount paid (if a deposit was already received)
- Balance due — what's actually owed now
If you operate in a country with multiple tax rates (UK VAT, GST in Canada/Australia, sales tax in the US), show each rate as its own line. Don't bundle.
9. How to pay you
This is the field most freelancers under-do. The easier you make payment, the faster it happens. Include whichever apply:
- Bank account name, number, routing/SWIFT/IBAN
- PayPal email or Payment Link
- Wise / Revolut / Payoneer details
- A Stripe checkout URL
- A "pay now" link if you have one
Put the most-used option first. Don't make the client choose between four equally-presented options — choice creates friction.
The optional fields worth including
Notes — a one-line thank-you, or a heads-up about anything unusual. Keeps the relationship warm.
Terms — your late-fee policy ("1.5% per month on overdue balances"), early-payment discount ("2% if paid within 10 days"), or anything contract-specific that needs to be visible at payment time.
Five mistakes that delay payment
1. Sending the invoice at month-end. Most AP departments process invoices on a weekly or bi-weekly cycle. An invoice that lands on the 30th can miss two cycles. Send the day the work is complete.
2. PDF named "invoice.pdf". Use a specific filename: invoice-INV0042-2026-05-13.pdf. It survives the client's downloads folder and turns up in search.
3. Asking the client to "reply with your remittance details". You don't need remittance details to get paid in 2026. Drop the line — it slows things down.
4. Including a discount field with $0 in it. The client sees "Discount" and asks for one. Don't show empty fields.
5. Forgetting to update the invoice number. Every invoicing tool has caught me doing this once. Two invoices with the same number cause real bookkeeping headaches. Use a tool that auto-increments.
What to do if the client doesn't pay
Send a polite reminder one day after the due date. Most overdue invoices are forgotten, not refused. If you don't hear back in a week, send a firmer one referencing the original. After three weeks, pick up the phone — or, if the relationship has soured, forward the issue to a collections service. Most legitimate clients pay long before that point if you stay calm and persistent.
A 60-second invoice
Open the free invoice generator. Fill in From, Bill to, one line item, and Total. Pick your currency. Click Download PDF. The whole thing should take less than a minute. The PDF you download has no watermark and no upsell. You're done.