What Information Goes on an Invoice? (Complete Checklist)

A lot of first-time invoices get rejected or delayed because they are missing something the client's accounting department requires. A PO number, a business address, a tax ID. These are easy things to fix, but the fix often takes two weeks because the invoice has to go back through the approval queue.

This is a complete checklist of everything that can go on an invoice, organized by what is required, what is situationally required, and what is optional. Use it the first time you invoice a new client to make sure nothing is missing.

Required on Every Invoice

These fields belong on every invoice you send, regardless of client type, project size, or country.

1. The Word "Invoice"

Put "Invoice" at the top of the document. This sounds obvious, but documents labeled "Bill," "Payment Request," or just a company name can create confusion in accounting systems. "Invoice" is the standard term, and using it makes the document immediately identifiable.

2. Your Name or Business Name

Your legal name if you are a sole proprietor, or your business name if you operate under one. If you have a DBA (doing business as), list both. Example: "Logan Moore dba Moore Creative."

3. Your Contact Information

At minimum: email address and phone number. Adding your mailing address is good practice and is required in some countries for invoices above certain amounts. If you have a business website, include it. This is also what gets used if your invoice is forwarded to accounts payable and someone needs to reach you.

4. Invoice Number

A unique identifier for each invoice. Start at 001 and go up sequentially. Some freelancers use a date-based format like 2026-047 (year plus sequence). The format does not matter as long as it is unique and consistent. Invoice numbers create a paper trail and make it easy to reference specific documents in conversations.

5. Invoice Date

The date the invoice is issued. This is the starting point for your payment terms. If your terms are Net 30 and the invoice date is June 1, payment is due July 1. The invoice date also matters for your accounting records and for the client's records.

6. Due Date

When you expect payment. State this as a specific date ("Due: July 1, 2026") or as a payment window ("Payment due within 30 days of invoice date"). Both are clear. Never leave the due date blank, even if your terms are informal. Without a due date, "payment due soon" is not a real deadline.

7. Client's Name and Address

The full legal name of the person or business being billed, plus their billing address. If you are invoicing a company, get the correct billing address before you send the first invoice. Many larger companies have separate billing addresses from their operating addresses, and getting it wrong delays payment.

8. Itemized List of Services or Products

Describe what you are billing for. For each line item, include a description of the work, the quantity (hours, units, or number of deliverables), the rate or unit price, and the line total. Vague line items like "Services - $2,500" create questions. Specific ones like "Brand strategy workshop (4 hours at $175/hr) - $700" do not.

9. Subtotal

The total of all line items before any discounts or taxes. List this clearly before applying anything else.

10. Taxes (If Applicable)

Whether you need to charge tax depends on your location, your client's location, and the type of work. In the US, most service-based freelancers are not required to collect sales tax, but this varies by state. If you do charge tax, show the tax rate and the tax amount as separate line items so the client can see exactly what they are paying. Apply tax after any discounts.

11. Total Amount Due

The final number the client owes you. Make this the most visually prominent number on the invoice. Bold it, increase the font size, or both. There should be zero confusion about how much to send.

12. Payment Methods and Instructions

Tell your client exactly how to pay. If you accept bank transfer, include the account details. If you use an online payment link, include the URL directly on the invoice. If you take checks, specify who to make them payable to and where to send them. The more friction you remove, the faster you get paid. You can set this up to appear automatically on every invoice at WaffleInvoice.

Required in Certain Situations

These fields are not needed on every invoice, but they are required (or strongly expected) in specific contexts. Missing them when they are needed is a common reason invoices get delayed.

Purchase Order (PO) Number

Many mid-size and large companies issue a PO number before approving any vendor work. If your client gave you a PO number, it must appear on your invoice or their accounting system will not be able to match it to an approved purchase. Ask for the PO number before you start work, not after you have completed it. A missing PO number can delay your payment by 30-60 days while the client tracks down the right approval.

Your Tax Identification Number (EIN or SSN)

If you are invoicing for $600 or more in a calendar year, US clients are required to issue you a 1099 form at year end. They will need your tax ID for that. Some clients ask for it upfront via a W-9 form rather than on the invoice itself. Others want it on the invoice directly. Either way, be ready to provide it.

VAT or GST Number

If you are registered for VAT (common in the UK, EU, Australia, and elsewhere), your VAT or GST registration number must appear on your invoice and the VAT must be shown as a separate line item. Invoices without the required tax information are not valid for the client's own tax deduction, and they will send it back to you.

Business Registration Number

In some countries (particularly in Europe), limited companies and other registered businesses must include their company registration number on invoices. Check the requirements for your country.

Billing Period

For retainers, subscriptions, or ongoing services, specify the date range the invoice covers. "Social media management services, May 1-31, 2026" makes the invoice self-explanatory and prevents questions about what the payment is for.

Project or Contract Reference

If your client operates with contracts, referencing the contract number on the invoice ties the payment to a specific agreement. "Per contract #2026-08 dated March 1, 2026" is useful when a client's legal or procurement team reviews payments.

Optional But Often Useful

Your Logo

A logo makes your invoice look professional and makes it easy for clients to identify who sent it at a glance. It is not required, but it takes 30 seconds to add if you have one.

Late Payment Terms

Stating your late fee policy on the invoice ("Invoices not paid within 30 days are subject to a 1.5% monthly late fee") gives you standing to charge it later. If it is not on the invoice, clients can reasonably argue they did not know about it.

Early Payment Discount

If you want to incentivize faster payment, note the discount terms: "2% discount if paid within 10 days." This is common on larger invoices where the discount is meaningful enough to motivate action.

Notes

A short notes section for anything project-specific that does not fit elsewhere. Common uses: thank-you message, reminders about upcoming work, or instructions about what to include on the payment reference. Read more about how to write invoice notes and terms effectively.

Payment Link

If you accept online payments, including a clickable payment link directly on the invoice dramatically speeds up collection. Clients should not have to log into anything or contact you to figure out how to pay. One click, done.

What to Leave Off Your Invoice

A few things that do not belong on most invoices:

• Unpaid balances from other projects. Each invoice should cover one project or billing period. Do not bundle old unpaid amounts into a new invoice without creating a separate line item that clearly identifies the old balance. Mixing old and new charges creates confusion and disputes.
• Estimates or quotes. If you want to provide an estimate, send a separate estimate document. An invoice is a request for payment, not a proposal. Mixing the two confuses the client about whether they have approved the work.
• Overly detailed internal notes. Notes about your process, time tracking details that the client did not ask for, or internal cost breakdowns. Invoice descriptions should explain what was delivered, not how you spent your hours internally.

Building Your Invoice Checklist

Here is the short version you can run through before sending any invoice:

• "Invoice" label at the top
• Your name or business name and contact details
• Invoice number (unique, sequential)
• Invoice date and due date
• Client name and billing address
• Line items with descriptions, quantities, rates, and line totals
• Subtotal, any discounts, taxes, and final total
• Payment instructions
• PO number (if required by the client)
• Tax ID or VAT number (if applicable)
• Billing period (for ongoing work)

If you are working from a template, WaffleInvoice's Word invoice template has all these fields built in. Or use the free invoice generator to create a professional invoice online in about 3 minutes with no account required.