How to invoice clients in the UK (step-by-step)

What must be on a UK invoice

Whether you're a sole trader or a registered limited company, HMRC requires you to include specific information on every invoice. Missing any of these doesn't just look unprofessional — it can delay payment and cause problems if HMRC ever reviews your records.

• A unique invoice number. Invoice numbers must be sequential — no gaps, no duplicates. You can use any format (INV-001, 2026-042, etc.) but HMRC expects you to maintain a consistent, unbroken sequence. If you skip a number, be prepared to explain why.
• Your business name and contact details. Your trading name, address, phone number, and email. If you're a limited company, you must also include your registered company name, registered address, and Companies House number.
• Your customer's name and address. The full name (or company name) and address of who you're invoicing. For businesses, use their registered or trading address.
• Date of the invoice and date work was completed. These can be the same date. The invoice date is when you raised it; the service date is when the work was done. Both help resolve payment disputes.
• A clear description of the goods or services. Vague descriptions like "work completed" cause disputes. Be specific: "Replace consumer unit (17th Edition RCBO board)" is far better than "electrical work." It also protects you if the client queries what they're paying for.
• The amount being charged, broken down where useful. For multi-item jobs, list each line separately. For labour + materials, show them as separate lines. This transparency builds trust and reduces payment delays.
• Payment terms. "Payment due within 14 days" or "Due on receipt" — you must state this clearly. Without payment terms, the legal default under UK law is 30 days for business-to-business invoices, which is longer than most sole traders want to wait.
• How to pay. Your bank sort code and account number for bank transfers. If you accept card payments (via a payment link or terminal), include that too. The easier you make it to pay, the faster you get paid.

VAT invoicing requirements in the UK

If you're not VAT-registered, you don't charge VAT and you don't need to include it on your invoice. Simple.

If your taxable turnover exceeds the VAT registration threshold (currently £90,000 per year), you must register for VAT and issue VAT invoices. Once registered, every invoice must include:

• Your VAT registration number
• The VAT rate applied to each item (e.g. 20%, 5%, or 0%)
• The VAT amount charged per line item
• A subtotal before VAT
• The total VAT amount
• The final total including VAT

Most trades work at the standard rate of 20%. However, some domestic energy efficiency work qualifies for the reduced 5% rate, and new residential builds may qualify for 0%. If you work across these categories, get comfortable breaking out each line at its correct rate — or use invoicing software that does it for you.

Common VAT mistake:issuing invoices that show a "VAT included" total without breaking out the VAT amount separately. This is non-compliant and can cause problems with business clients trying to reclaim their input VAT.

Example UK invoice

This invoice covers two clear line items with separate amounts — no vague "electrical work" description. The payment method and deadline are stated up front. Use our free UK invoice generator to create something similar in under 60 seconds, no signup needed.

How to send an invoice to a client

Getting the invoice right is only half the job. How and when you send it matters just as much.

• Send it the same day the job is finished. The moment you walk off site is the best time to invoice. The work is fresh in both your minds, the customer is satisfied, and there's no awkward gap where they've moved on. Research consistently shows that same-day invoicing leads to faster payment than invoicing at end-of-week or end-of-month.
• Email as PDF. PDF is the standard format for UK invoices — it's professional, can't be edited by the recipient, and most clients know what to do with it. Include a brief, friendly note in the email body: "Thanks for the work today — invoice attached. Payment by [date] is appreciated."
• Include a payment link where possible. If you use invoicing software, you can include a card-payment link directly in the invoice. Customers can pay by tapping a link on their phone — no logging in to online banking, no copying sort codes. This alone can cut the time between sending and receiving payment from weeks to hours.
• Invoice from your phone. If you're on the road all day, invoicing from a laptop when you get home means evening admin. Mobile invoicing apps let you send a full, professional invoice from the job site before you even drive away. Most UK electricians, plumbers, and cleaners using WrkGenie send their invoice on the way to the next job.

Common UK invoicing mistakes

• Vague descriptions. "Labour" or "services rendered" tells the client almost nothing. Disputes about what was done — and therefore whether the price is fair — are much more common when descriptions are unclear. Write a one-line summary of the actual work: "Annual boiler service and safety check" or "Full bathroom tiling, 14sqm."
• Skipping invoice numbers. HMRC requires sequential numbering. Don't restart the count every year unless you use a clear prefix (e.g. INV-2026-). Don't leave gaps. If you cancel an invoice, keep a record of the cancelled number rather than just deleting it.
• No payment terms. "Payment on receipt" or "within 14 days" is the minimum. Without stated terms, the legal default is 30 days for business clients — and many will take the full 30, or longer. Set 7 or 14 days and it changes payment behaviour.
• Sending invoices late. The longer you wait after the job, the longer you'll wait to be paid. Aim for same-day. End-of-month batch invoicing might feel efficient, but it means some jobs sit for three to four weeks before a client even receives the invoice.
• No way to pay. Bank details should be on every invoice. If you accept card payments, include that option too. Removing friction from the payment process is one of the simplest things you can do to get paid faster.
• Incorrect VAT handling. If you're VAT-registered and don't break out VAT correctly, your invoice is technically non-compliant. Business clients can't reclaim input VAT from a non-compliant invoice, which creates friction and sometimes leads to delayed payment.

How to chase unpaid invoices

Late payment is one of the most common frustrations for UK sole traders and small businesses. Often, it's not deliberate — clients are busy, invoices get missed, or the email went to spam. A professional, consistent follow-up process gets results without damaging relationships.

• Send a polite reminder when the due date passes. Keep it short and friendly: "Hi [Name], just a quick note — Invoice #042 was due on [date]. Please let me know if you need me to resend it." Most late payments are resolved at this stage.
• Follow up again after 7 days. If no response, send a firmer follow-up. Reference the invoice number and original due date, and ask them to confirm when they'll pay.
• Keep records of every communication. If you ever need to escalate — whether that's a formal Late Payment Notice, small claims court, or a debt recovery service — you'll need a clear record of when you invoiced, what the terms were, and every follow-up you made.
• Set payment expectations before the job. The easiest late-payment problem to avoid is the one you prevent upfront. Before starting work, confirm verbally or in writing how and when you'll invoice, and what your payment terms are. Most clients respect this — and it removes the awkwardness later.

Invoice templates vs invoicing software

A Word or Excel invoice template can work fine when you're just starting out. But as your client list grows, the admin problems stack up quickly.

With a template, you manually track every invoice. You copy-paste client details and descriptions. You remember — or forget — to follow up on unpaid ones. You search through email attachments to find out if someone paid three months ago. And when you need to quote a new job, you're rebuilding a document from scratch.

Invoicing software handles the admin automatically. Client details are saved. Invoice numbers are assigned automatically. You can see at a glance which invoices are paid, outstanding, or overdue. Reminders can go out without you thinking about them. And your quote can become an invoice in a single click when the job is done.

For UK sole traders and small service businesses, the switch from templates to software typically saves between two and five hours of admin per week — and often pays for itself many times over through faster payment alone. See our comparison of the best invoicing software for UK trades or WrkGenie pricing if you're ready to make the switch.

Next steps

• Create a free UK invoice now (no signup)
• How to quote a job in the UK
• See WrkGenie pricing
• Invoicing for electricians
• Invoicing for plumbers
• Invoicing for cleaners

Frequently asked questions