How do I invoice a client as a freelancer? Invoicing feels intimidating the first time — what must it include? When do I send it? What if they don’t pay? — but it’s genuinely simple once you’ve done it once. A proper invoice is part admin, part psychology: clear, professional invoices get paid faster, and the payment terms you set determine whether you’re chasing money or receiving it. Here’s everything: the legal requirements, the tools, and the habits that get you paid on time.

What a UK invoice must include

Legally, your invoice needs:

• A unique invoice number — sequential (001, 002…). Gaps raise eyebrows; keep it clean.
• Your business name and address (and company number if limited).
• The client’s name and address.
• A clear description of what you’re charging for — dates, hours, deliverables. Vague invoices get queried; queried invoices get delayed.
• The date of the invoice and the supply date (when the work was done).
• Amounts: subtotal, VAT if registered (with your VAT number), and total due.
• Payment terms: due date and how to pay (bank details — never ask for cheques in 2026).

If you’re VAT-registered, additional rules apply (VAT number, rate breakdown, etc.) — your accounting software handles this automatically.

How do I invoice a client as a freelancer? The practical steps

• 1. Agree terms upfront — rate, scope, payment terms (14 or 30 days), and late-payment consequences — before starting work. An email confirmation counts. Invoicing disputes are almost always scope/terms disputes in disguise.
• 2. Use proper software — free tiers of Wave, Zoho Invoice, or Starling/Monzo’s built-in invoicing; paid options like FreeAgent or Xero (£10–£25/month) for established freelancers. Software numbers invoices, tracks who’s paid, sends reminders, and exports for tax returns. Spreadsheets work but don’t scale — switch by your tenth invoice.
• 3. Invoice promptly — send it the day the work completes (or per your agreed schedule for ongoing work). Every day you delay invoicing is a day you delay payment. Set a weekly invoicing ritual if you do ongoing work.
• 4. Make paying effortless — bank transfer details prominent, and consider adding card/Stripe payment links (the fee is worth it for faster payment). The harder it is to pay you, the later they pay.
• 5. Track everything — know at a glance what’s sent, what’s due, what’s overdue. Your software’s dashboard is your cash-flow command centre.

Payment terms: setting yourself up to be paid

• Standard terms: 14 days is increasingly normal for freelancers; 30 days is the corporate default. Shorter is better — there’s no law requiring 30 days.
• Deposits for new clients: 25–50% upfront for projects is standard professional practice, not rudeness. It filters out non-serious clients and protects your cash flow.
• Milestone payments for larger projects — never let more than a few weeks’ work go unbilled.
• Late payment terms in writing: state that statutory interest (Bank of England base rate + 8%) and compensation (£40–£100 per invoice under the Late Payment of Commercial Debts Act) apply. You don’t have to enforce it — but stating it focuses minds. See our late payments guide for the full playbook.
• Consider early-payment discounts (2% for payment within 7 days) if cash flow matters more than margin.

When they don’t pay: the escalation ladder

• Day 1 overdue: friendly nudge — “just checking this didn’t get lost.” Most late payments are admin errors, not malice.
• Week 2: firmer email restating terms and the due date, with the invoice reattached.
• Week 4: formal letter/email invoking late-payment interest and compensation, setting a final deadline (7–14 days).
• Beyond: letter before action, then Money Claims Online (small claims court) — £35–£455 in fees depending on amount, recoverable if you win. The process is designed for non-lawyers and most claims settle before court.
• Throughout: stay professional and factual in writing. Never threaten what you won’t do; always follow through on what you threaten.

Prevention beats cure: credit-check new clients (a quick Companies House look is free), get deposits, and trust the red flags — clients who haggle hard on price and terms often haggle hard on payment too.

Invoicing and tax: the connection

Your invoices are your income record for Self Assessment — keep copies for 6 years (your software does this automatically). Invoice dates determine which tax year income falls in, which matters near year-end. And if you’re approaching the VAT threshold, invoice totals are what HMRC looks at — see VAT registration. For the full financial picture, read our guides on freelancer bookkeeping and claimable expenses.

Invoicing across borders: international clients

Freelancing for overseas clients adds wrinkles: currency — invoice in the client’s currency or yours? Invoicing in pounds transfers exchange risk to the client; invoicing in their currency is friendlier but exposes you to rate movements. For regular foreign income, a multi-currency account (Wise is the freelancer favourite) receives dollars/euros with minimal fees versus bank exchange markups. VAT on exports — services to business clients outside the UK are generally outside the scope of UK VAT (with exceptions — check the place-of-supply rules for your service type). Payment methods — bank transfer works but is slow and fee-heavy internationally; Wise, PayPal or Stripe cut costs dramatically. Contracts — specify governing law and payment currency upfront; chasing a late payer across jurisdictions is miserable, so deposits matter even more internationally. The admin is slightly heavier, but international clients often pay better rates — worth the paperwork.

For larger invoices or slow-paying sectors, know about invoice finance: factoring or invoice discounting advances you most of an invoice’s value immediately (typically 80–90%), with the financier collecting from your client. It costs 2–5% of the invoice value — expensive as a habit, but invaluable when a big invoice and an empty bank account collide. Use it as an occasional bridge, not a business model; if you’re factoring every invoice, the underlying problem is payment terms or client selection, not cash flow timing. The best use is strategic: taking on a bigger project than your reserves would otherwise allow.

The bottom line

How do I invoice a client as a freelancer? Agree terms in writing before starting, use proper invoicing software (free tiers are fine to start), include all legal details with a unique number, send promptly on completion, make payment effortless, set 14-day terms with deposits for new clients, and escalate politely but firmly when overdue. Professional invoicing isn’t just admin — it’s the system that turns work done into money received, on time, without awkwardness.

GOV.UK invoicing rules set out the legal requirements.