Guides

Plain-English help with UK invoicing, VAT, CIS and the construction reverse charge. Looking for a ready-made start? See our invoice templates by trade and profession.

• How to write an invoice (UK) — step by step

  A simple step-by-step guide to writing a professional, compliant UK invoice, what to put on it, and what changes if you are VAT registered.

• Do I need to charge VAT?

  When UK sole traders and small businesses must register for VAT — the £90,000 threshold, the two tests, deadlines, and whether registering voluntarily is worth it.

• How to invoice when you're not VAT registered

  What a non-VAT invoice must include, what to leave off, what to say when a client asks for a VAT invoice, and how to switch over when you register.

• What a UK VAT invoice must include

  HMRC's required fields for a full VAT invoice, the rules for simplified invoices under £250, VAT rates, invoice numbering, tax points and foreign-currency invoices.

• How to number invoices (and why gaps matter)

  How to number UK invoices correctly — unique and sequential numbering, prefixes and year resets, separate series for quotes and credit notes, and how to fix a broken sequence.

• Invoice payment terms explained (Net 30, due on receipt & more)

  What invoice payment terms mean in the UK — Net 30, due on receipt, deposits and stage payments — plus the statutory default if you don't set any.

• Quotes and estimates — and how to turn one into an invoice

  The difference between a quote, an estimate and an invoice, what a good quote includes, and how to convert an accepted quote into an invoice.

• Quote vs estimate — what's the difference?

  Which is legally binding, who carries the risk when a job overruns, how to word an estimate so it isn't treated as a fixed price, and when to use each.

• Invoice vs receipt — what's the difference?

  How an invoice and a receipt differ, when you must issue each, what a simplified VAT invoice under £250 needs, and how deposits and part-payments fit in.

• CIS invoices and the construction reverse charge

  How CIS subcontractors invoice contractors — deduction rates (20/30/0%), the labour-vs-materials split, and the VAT domestic reverse charge for construction.

• Sole trader vs limited company — invoicing differences

  How invoicing differs between a sole trader and a limited company in the UK — what each must show, company number rules, and how VAT works for both.

• What is a proforma invoice?

  When to use a proforma invoice, what to put on it, why it isn't a VAT invoice, and how it affects tax points and reclaiming VAT.

• What is a credit note and how to issue one

  When to use a credit note to cancel or correct an invoice, what it must include, and how credit notes affect VAT.

• How to charge interest on late payments (UK)

  How statutory interest and fixed compensation work on overdue business invoices, when interest starts, and how to claim it.