What Makes a Professional Invoice?

A professional invoice is more than just a request for payment — it's a legally binding document that protects both you and your client. In the UK, HMRC has specific requirements for what must appear on an invoice, especially if you're VAT registered.

What Must Be on Every UK Invoice

Whether you're a freelancer, sole trader, or limited company, every invoice must include:

  • Your business name and address
  • Client's name and address
  • A unique invoice number — sequential numbering helps with bookkeeping
  • Issue date — the date you created the invoice
  • Due date — when payment is expected
  • Description of goods or services
  • Amount charged — itemised where possible
  • Total amount due

Additional Requirements for VAT-Registered Businesses

If you're VAT registered (mandatory above £90,000 turnover), you must also include:

  • Your VAT registration number
  • The VAT rate applied to each item
  • The VAT amount charged
  • The net amount before VAT

Invoice Numbering Best Practices

Use a consistent numbering system. Common formats include:

  • INV-2025-001 — year-based sequential
  • INV-001 — simple sequential
  • ABC-2025-001 — company initials prefix

Never reuse invoice numbers — each must be unique for audit purposes.

Payment Terms to Include

Always state your payment terms clearly. Standard UK payment terms are:

  • Net 30 — payment due within 30 days
  • Net 14 — payment due within 14 days
  • Due on receipt — immediate payment expected

Under the Late Payment of Commercial Debts Act, you're entitled to charge 8% above the Bank of England base rate on overdue invoices from businesses.

How to Get Paid Faster

Studies show that invoices with clear payment instructions are paid 3x faster. Include:

  • Your bank details (sort code and account number)
  • A clear due date — not just "30 days"
  • A polite but firm payment reminder in your notes section

Create Your First Invoice Free

invly makes it simple to create professional UK invoices in minutes. Choose from multiple PDF templates, add your logo, and send directly to clients — all free forever.