# Why Your Freelancer Invoice Matters > A freelancer invoice checklist for your details, client details, dates, amounts, and payment terms, with UK rules and common mistakes. ## The freelancer invoice checklist If an invoice does not have all the details, the client often sends a question instead of a payment. Read your invoice against each item before you send it. ### Your details - [ ] Your legal name, and your business name if you use one - [ ] Your business address (a PO box or a virtual address is acceptable if the client accepts it) - [ ] A business email address and a phone number for questions about invoices - [ ] Your tax or registration number, if you have one (for example, an EIN in the US, or a VAT number) An EIN is a US federal tax number for businesses. VAT is value-added tax, a sales tax in the UK, the EU, and other countries. ### Client details - [ ] The full legal company name of the client, not a short name - [ ] The name and email address of the person who processes invoices (often a different person from your project contact) - [ ] The billing address, as the client gave it to you - [ ] The purchase order (PO) number, if the client uses PO numbers ### Invoice number and dates - [ ] A unique invoice number from one series (INV-001, INV-002, or 2026-001, 2026-002) - [ ] The invoice date (the day that you send the invoice) - [ ] A due date as a calendar date ("Due April 14, 2026"), not only payment terms - [ ] Payment terms that are the same as in your contract (for example, Net 30, which means payment within 30 days of the invoice date) ### Work details - [ ] The project name or the reference that the client uses - [ ] The dates of the work - [ ] A description that a person in accounts payable (the team that pays bills) can understand without help - [ ] One line for each deliverable (a finished piece of work), or hours × rate for hourly work - [ ] A reference to the contract or statement of work ("Per Service Agreement dated January 15, 2026") ### Amounts - [ ] The subtotal before tax - [ ] Each tax on a separate line with its rate, if you must charge tax - [ ] Deposits or retainers (advance payments) that the client paid, subtracted on a separate line - [ ] The total due, as the largest number on the page - [ ] The currency ("USD", "GBP", "EUR") ### Payment details - [ ] Each payment method that you accept - [ ] Bank details for transfers (account name, bank, account number, routing number, and the SWIFT/BIC code, the international bank code, for wires from other countries) - [ ] A payment link or a platform handle, if you use one - [ ] Late fee or interest terms, only if your contract and local law permit them - [ ] The line "Please include the invoice number with your payment" ### Before you send - [ ] The line items add up to the subtotal, and the subtotal plus tax equals the total - [ ] The invoice goes to the billing contact as a PDF - [ ] You saved a copy with the date sent and the due date ## The purpose of each section A complete invoice has four parts: your details, the client details, the amounts, and the payment methods. With all four parts, the client can process the invoice without questions. ![A complete invoice has four parts, business details, client details, financial breakdown and payment methods, and together they let the client process it quickly](/assets/blog/freelancer-invoice-checklist/diagram_complete-invoice-business.webp) Your details tell the client who to pay. The client also uses them to find you in its vendor records. In the US, clients usually ask for a [Form W-9](https://www.irs.gov/forms-pubs/about-form-w-9). The W-9 gives the client your taxpayer identification number for the information returns that the client files. Put your SSN or EIN on the W-9. You do not have to print your SSN on the invoice. The client details decide if the invoice gets to the person who can pay it. At the start of the project, ask the client who gets invoices and at which email address. Also ask if the client needs a PO number on the invoice. Large companies often hold an invoice that has no PO number. The invoice number and dates let you and the client track the invoice. Do not use an invoice number two times. If an invoice is wrong, mark it as void and send a new invoice with a new number. Then your records show what happened. The work details prevent disputes months later. "Design work: $2,500" causes questions. "Homepage redesign: hero section, services overview, contact form, three revision rounds, final design approved February 28, 2026" does not. For hourly work, show the tasks: "Homepage design: 12 hours × $125 = $1,500." Your location, the location of the client, and the type of work decide if you must charge sales tax, VAT, or GST. In the US, each state decides which services are taxable. If you are not sure, ask an accountant. If you and your client are both registered for VAT in the UK, you must send a VAT invoice. A VAT invoice shows [your VAT number and the VAT as a separate amount](https://www.gov.uk/vat-record-keeping/vat-invoices). For cross-border work in the EU, the client sometimes pays the VAT instead of you. This is the reverse charge. In that case, the invoice must include [the words "reverse charge"](https://taxation-customs.ec.europa.eu/taxation/vat/vat-businesses/vat-invoicing_en). The payment details tell the client how to pay. If the client must send you an email to ask how to pay, the payment comes days later. ## If you send invoices from the UK GOV.UK lists the items that [every invoice must include](https://www.gov.uk/invoicing-and-taking-payment-from-customers/invoices-what-they-must-include). They are a unique number, your name, address, and contact details, and the name and address of the customer. They also include a description, the supply date, the invoice date, the amounts, the VAT if applicable, and the total that the customer owes. A sole trader (a self-employed person) must also show his or her own name and any business name. A sole trader who uses a business name must also give an address for legal documents. If a business pays you late, you can claim [statutory interest of 8% plus the Bank of England base rate](https://www.gov.uk/late-commercial-payments-interest-debt-recovery/charging-interest-commercial-debt). Statutory interest is interest that the law sets. A different rate in your contract replaces this rate. ## Mistakes that delay payment When the information on an invoice is complete, the client processes the payment. When information is missing, the invoice comes back with questions, and you must send it again. ![When the client reviews an invoice with complete information, the client pays. With missing information, the invoice leads to delays, follow-ups, and a resend](/assets/blog/freelancer-invoice-checklist/diagram_send-invoice-client.webp) Look for these mistakes before you send an invoice: 1. No payment instructions. The client approves the invoice and then asks how to pay. 2. A vague description. Six months later, "consulting services" tells the client nothing, also at tax time. 3. No contract reference. A question about the rate or the scope becomes a dispute about the agreement. 4. The wrong recipient. The invoice stays in the inbox of your project contact and does not get to accounts payable. 5. No currency. "$3,000" is not clear to a client in Canada or Australia. 6. No follow-up. Some late payments are invoices that nobody saw. Send a short, polite email a few days after the due date: "I am writing about invoice 2026-045, due April 14. Can you tell me the status? I can send it again if necessary." ## Use this checklist with Claude or ChatGPT Before you send an invoice, Claude or ChatGPT can compare it with this checklist. Paste the checklist and the invoice text, or attach the PDF. Also paste the payment terms from your contract. ```text Below is a freelancer invoice checklist, my invoice, and the payment terms from my contract. Check the invoice against every checklist item and answer Pass, Fail or Not applicable for each. Recalculate every line item, the subtotal, tax and total, and show your math. Then list what is missing or wrong. CHECKLIST: [paste the checklist] INVOICE: [paste the invoice] CONTRACT TERMS: [paste rate, payment terms, PO number] ``` Make sure that each answer is correct before you change the invoice. AI assistants can make arithmetic errors, and they can miss or invent problems. Calculate again each amount that the assistant reports as wrong. Remove bank account numbers and tax numbers before you paste the invoice. Also read the data settings of your workspace. For questions about tax or late fees, ask an accountant or your tax authority. An AI assistant does not give the final answer on these questions. A docs portal with Ask AI and support tickets Connect a repository, or describe your product to start. Each docs site has search, Ask AI, an API console, an MCP server and support tickets. Publishes from GitHub on every push Works with Mintlify repositories API console from your OpenAPI file MCP server and llms.txt for AI agents Ask AI and support tickets Analytics for people and AI agents Start Free → Questions? Ask AI in our docs No card required. ## Frequently Asked Questions ### How long do I keep copies of my invoices? In the US, the IRS generally tells you to keep tax records for three years, and longer in some cases. In the UK, self-employed people must keep records for at least five years after the January 31 submission deadline of the tax year. Keep each invoice with the date that you sent it and the date that the client paid. ### Can I ask for a deposit before I start the work? Yes, if the client agrees. Write the deposit amount and the due date in the contract. Send a deposit invoice before the work starts. On the final invoice, subtract the deposit on a separate line. --- [View the canonical page](https://revdoku.com/blog/freelancer-invoice-checklist/) · [Browse llms.txt](https://revdoku.com/llms.txt)