Self-employed invoicing: the complete guide

Going self-employed is exciting — but the admin side can feel overwhelming. Invoicing is one of the first things you need to get right: it's how you get paid, how you keep records for HMRC, and how you look professional to clients.

This guide walks you through everything, from the basics of registering to sending invoices that actually get paid on time.

Before you send your first invoice

Register as self-employed with HMRC

You must register with HMRC as self-employed by 5 October in your business's second tax year. For example, if you started freelancing in June 2026, you must register by 5 October 2027.

However, it's better to register as soon as you start. You can do it online at gov.uk — it takes about 10 minutes. You'll get a Unique Taxpayer Reference (UTR) number by post within 10 working days.

Understand your record-keeping obligations

HMRC requires you to keep records of:

• All sales and income (invoices you send)
• All business expenses (receipts and invoices you receive)
• VAT records if you're VAT-registered

Records must be kept for at least 5 years after the 31 January deadline. Digital records are acceptable — you don't need a filing cabinet full of paper.

Decide on your business structure

Most freelancers start as sole traders. It's the simplest structure — you and the business are legally the same entity. You report your income on a Self Assessment tax return each year.

If your earnings grow significantly, you might consider incorporating as a limited company. This is a separate legal entity with different tax implications. Talk to an accountant when you're approaching £50,000+ annual profit.

What to include on your invoices

Every invoice should include:

1. Your name or business name and contact details
2. Your client's name and address
3. A unique, sequential invoice number (INV-001, INV-002, etc.)
4. The invoice date
5. A clear description of what you did
6. The amount due — itemised with quantities and unit prices
7. The total amount
8. Your payment terms — when you expect payment (e.g., Net 30)
9. Your payment details — bank account, sort code, or payment link

For a detailed breakdown with examples, see our guide to writing invoices.

If you're VAT-registered, there are additional requirements — see UK VAT invoice requirements.

Choosing your payment terms

Payment terms are the rules for when and how your client pays. The most common options:

• Due on receipt — immediate payment
• Net 14 — within 14 days
• Net 30 — within 30 days (most common)
• Net 60 — within 60 days (common with larger companies)

As a new freelancer, don't be afraid to ask for shorter terms. Net 14 or even due on receipt is reasonable for small projects. Longer terms suit ongoing retainer relationships where trust is established.

Always state your terms on the invoice and agree them with your client before starting work. Getting this in writing — even an email confirmation — protects you if there's a dispute.

How to actually send invoices

You have several options:

Option 1: Free invoice generator

If you just need to create a one-off invoice quickly, use a free invoice generator. You enter your details, add line items, and download a PDF. No account needed.

The downside: no tracking, no payment links, no automatic reminders.

Option 2: Invoicing software

A dedicated invoicing tool like Coinvoice handles the entire workflow:

• Create professional invoices from templates
• Send by email with a "Pay Now" button
• Accept card and PayPal payments directly
• Track when clients view your invoice
• Automatic reminders for overdue invoices
• Expense tracking and receipt scanning
• Reports for your tax return

Most of these features are free — Coinvoice's free plan includes unlimited invoices for up to 25 clients. See our pricing page for details.

Option 3: Spreadsheet or Word template

You can create invoices in Excel or Google Docs using an invoice template. This works but doesn't scale — you'll spend time on formatting, manual numbering, and chasing payments by email.

Getting paid faster

The average UK freelancer waits 30+ days for payment. Here's how to shorten that:

1. Include a payment link. If your client can pay with one click, they're more likely to pay immediately. Invoices with online payment options get paid up to 3x faster than bank-transfer-only invoices.

2. Send the invoice immediately. Don't wait until the end of the month to batch your invoicing. Send each invoice as soon as the work is delivered.

3. Follow up promptly. If payment is overdue, send a polite reminder on day 1. Then again on day 7. Don't feel awkward — you did the work, you deserve to be paid. See our guide to dealing with late payments.

4. Offer early payment discounts. "2/10 Net 30" means the client gets a 2% discount if they pay within 10 days, otherwise the full amount is due in 30 days. Some clients will take the discount every time.

5. Use recurring invoices for retainers. If you do ongoing work for a client, set up a recurring invoice so it goes out automatically each month. One less thing to remember.

Tax and invoicing

As a self-employed person in the UK, you pay:

• Income Tax on your profits (after deducting allowable expenses)
• National Insurance contributions (Class 2 and Class 4)
• VAT if your taxable turnover exceeds £90,000

Your invoices are the primary record of your income. Keep them organised and make sure the totals match what you report on your Self Assessment return.

Allowable expenses reduce your taxable profit. Track everything: software subscriptions, home office costs, travel, phone bills, professional development. Coinvoice's expense tracking with receipt scanning makes this straightforward.

Your first invoice checklist

• [ ] Registered as self-employed with HMRC
• [ ] Chosen your invoicing tool or template
• [ ] Set up your business details (name, address, logo)
• [ ] Agreed payment terms with your client
• [ ] Created the invoice with all required fields
• [ ] Double-checked the amounts and client details
• [ ] Included a payment link or bank details
• [ ] Sent the invoice and noted the due date
• [ ] Set a reminder to follow up if not paid on time

Ready to send your first invoice? Get started with Coinvoice — free for up to 25 clients, no credit card required.