Contractor Invoice Template UK: What to Include (2026)

If you're a contractor in the UK — whether you operate through a limited company, as a sole trader, or via an umbrella company — knowing how to invoice correctly is essential. A well-structured invoice gets you paid faster and keeps you compliant with HMRC.

This guide covers exactly what to include on a UK contractor invoice, common mistakes to avoid, and how to create one in minutes.

What Is a Contractor Invoice?

A contractor invoice is a formal request for payment that you send to your client or end client. It records:

• The work you've done
• The amount owed
• Your payment terms and bank details

For contractors, invoices also serve as your financial record for self-assessment tax returns and VAT purposes.

What to Include on a Contractor Invoice (UK)

1. Your Business Details

• Your name or company name — if you're a limited company, use your registered company name
• Your address — this can be your business address or registered office
• Company registration number — required if you trade through a limited company
• VAT number — only if you're VAT registered

2. Client Details

• Client name or company name
• Client address

3. Invoice Reference Number

Every invoice must have a unique invoice number. This helps you track payments and is required for proper bookkeeping. Use a sequential format: INV-001, INV-002, etc.

4. Invoice Date and Due Date

• Invoice date — the date you're issuing the invoice
• Due date — typically 30 days from invoice date for UK contractors, though you can negotiate shorter terms (14 or 7 days)

Under the Late Payment of Commercial Debts (Interest) Act 1998, if no payment date is agreed, UK businesses have a right to payment within 30 days.

5. Description of Services

Be specific. Rather than "consulting services," write:

"Software development services — 15 days at £400/day — March 2026"

A clear description:

• Reduces disputes
• Demonstrates the value delivered
• Helps clients approve invoices faster internally

6. Day Rate or Project Fee

Include either:

• Day rate invoicing: number of days × day rate
• Project fee: fixed amount for the engagement
• Milestone billing: amount for a defined deliverable

7. VAT (if registered)

If your annual turnover exceeds the VAT threshold (currently £90,000), you must register for VAT and charge it on your invoices.

A VAT invoice must show:

• Your VAT registration number
• The VAT rate applied (usually 20%)
• The VAT amount
• The total including VAT

8. Total Amount Due

Show:

• Subtotal (before VAT)
• VAT amount (if applicable)
• Total due

9. Payment Details

Include your:

• Bank name
• Account name
• Sort code
• Account number

Or, if you're using a payment service, include the relevant link or reference.

10. Payment Terms

State your terms clearly: "Payment due within 30 days of invoice date."

IR35 and Contractor Invoicing

If you're working inside IR35, your invoicing may be handled differently:

• Inside IR35: The fee-payer (agency or end client) deducts tax and National Insurance before paying you. You may still receive a net payment with a remittance advice rather than a standard invoice payment.
• Outside IR35: You invoice normally as a business and are responsible for your own tax and NI.

Always keep records of your contracts and IR35 determinations alongside your invoices.

Limited Company vs Sole Trader Invoices

| Element | Limited Company | Sole Trader | |---|---|---| | Name on invoice | Registered company name | Your name or trading name | | Company number | Required | Not required | | VAT number | If registered | If registered | | Tax paid | Corporation tax | Income tax / self-assessment |

Common Mistakes UK Contractors Make

1. Missing invoice numbers
Every invoice needs a unique number. Gaps in your sequence can look suspicious to HMRC.

2. Vague descriptions
"Consulting — April" won't satisfy a client's accounts department. Be specific about the work done.

3. Wrong payment details
Double-check your sort code and account number every time. Incorrect details delay payment by days.

4. No due date
Without a clear due date, clients have no urgency to pay. Always state a due date.

5. Forgetting to chase
UK contractor invoices are often paid late. Build a chase process: a polite reminder at 7 days overdue, a firmer one at 14, and a formal notice of late payment interest at 30.

Create a Contractor Invoice Free

Billdrop is a free invoice generator built for UK freelancers and contractors. You can:

• Create a professional invoice in under 2 minutes
• Download it as a PDF immediately — no account needed
• Add your logo, set VAT, and choose from multiple templates
• Save client details and manage invoice history with a free account

No subscription. No credit card. Just a clean, professional invoice.

Summary

A UK contractor invoice must include your business details, client details, a unique invoice number, a description of the work, your day rate or fee, VAT if applicable, and your bank details. For limited company contractors, also include your company registration number.

The clearer your invoice, the faster you get paid.