Complete Setup Checklist
Legal & HMRC registration
- Register for Self Assessment with HMRC (by 5 October in first tax year)Do first
- Register for CIS as a subcontractor if you plan any subcontract work
- Register for VAT once turnover exceeds or is expected to exceed £90,000
- Decide on sole trader or limited company structure — sole trader is right for most starting out
Qualifications & certifications
- Gas Safe registration — required before any gas work (annual renewal)Do first
- Check your insurance is valid for self-employed/commercial work (not just private domestic)Do first
- City & Guilds, NVQ Level 2/3 or equivalent — may need updating from employed training
- Consider additional qualifications: unvented hot water (G3), oil, renewables
Insurance
- Public liability insurance — minimum £1m, £5m recommendedDo first
- Employer's liability insurance if hiring anyoneDo first
- Van insurance with business use — trade use cover, not social and domestic onlyDo first
- Tools in transit insurance
- Personal accident / income protection insurance
Business bank account
- Open a dedicated business bank account — keep personal and business finances separate from day oneDo first
- Set up a tax savings pot (a separate savings account): save 25–30% of every payment for taxDo first
- Consider a business credit card for material purchases to track expenses
Van and tools
- Source a reliable van — the single most important business assetDo first
- Ensure van is sign-written or has magnetic signs — free rolling advertising
- Set up a well-organised tool kit and parts stock for common jobs
- Source a trade account with your local merchant (BSS, Wolseley, Graham, Screwfix Pro)
Pricing and quoting
- Calculate your minimum viable day rate before setting pricesDo first
- Set up a quote template with all required fieldsDo first
- Decide on callout fee structure — standard vs emergency rates
- Write a simple terms and conditions for deposits and cancellations
Invoicing and records
- Set up invoicing software — TraderInvoice is free for 5 invoices/monthDo first
- Create an invoice template with your business details, UTR, and bank detailsDo first
- Set up a system to track all income and expenses from day oneDo first
- Keep all receipts — van, fuel, tools, materials, insurance, Gas Safe, accountant
Getting customers
- Set up a Google Business Profile — free and essential for local search visibilityDo first
- Register on Checkatrade, TrustATrader, or MyBuilder for initial leads
- Ask satisfied customers for Google reviews — they are the fastest reputation builder
- Get a simple website — even a one-page site with your number and services helps
- Tell everyone you know — friends, family, former colleagues — that you have gone self-employedDo first
Realistic Start-Up Costs
| Item | Cost range | Notes |
|---|---|---|
| Van (used) | £5,000–£20,000+ | Or lease from £200–£400/month |
| Van insurance (business use) | £1,200–£2,500/year | Higher in first year, drops with no-claims |
| Public liability insurance | £200–£500/year | £5m cover standard for plumbers |
| Gas Safe registration | £160–£350/year | Required for any gas work |
| Tools and equipment | Mostly already owned | Budget £500–£2,000 for gaps |
| HMRC registration | Free | Register for Self Assessment online |
| Invoicing software | Free to start | TraderInvoice free tier: 5 invoices/month |
| Accountant (optional year one) | £300–£600/year | Worthwhile from year one to maximise expenses |
How to Price Your Work
Pricing correctly from day one prevents the most common new business mistake — setting rates too low and building a business that is exhausting but not profitable. Do not undercut the market to win jobs. Compete on quality, speed, and reliability — not price.
For detailed guidance on rates and minimum viable rate calculation, see our dedicated guides:
Getting Your First Customers
Most new plumbing businesses get their first customers through personal network, then build from Google reviews. The fastest path:
Tell everyone immediately
Text every person in your phone, post on local Facebook groups, message former colleagues. More first customers come from this than any other channel.
Google Business Profile (free)
Set it up on day one. It shows your business in local search and on Google Maps. Ask every customer for a review — 10 good reviews will bring you more work than any paid advertising.
Lead generation platforms
Checkatrade, TrustATrader, or MyBuilder give you access to homeowners actively looking for a plumber. Expect to pay £50–£200/month but they provide immediate, local leads.
Card and van sign-writing
Every job you do is an opportunity for the neighbour to see your van and take your card. Sign-write your van early — it pays for itself repeatedly.
Invoicing from Day One
Every job you do must have an invoice. An invoice creates a paper trail, triggers payment, and forms the basis of your tax return. Never leave a job without sending one — even if the customer pays cash on the day, issue a formal receipt invoice.
What your invoices need:
- Your business name and address
- Invoice number (sequential — start at 001)
- Date issued and payment due date
- Customer name and address
- Description of work done
- Labour and materials as separate line items
- Your bank details for payment
- UTR if you do any CIS subcontract work
TraderInvoice handles all of this. Speak your job in plain English from your phone, and it creates a complete, professional invoice. Free for up to 5 invoices per month — right-sized for a plumber just starting out.
Start invoicing professionally from day one
TraderInvoice is free for 5 invoices/month — no credit card required. Speak your invoice, send the PDF, get paid. Use promo code 04TI26 for a discount when you upgrade.
Create Free AccountFrequently Asked Questions
Do I need to register with HMRC before I start plumbing work as a sole trader?
- Yes — you must register for Self Assessment with HMRC by 5 October in the year after you start trading. So if you start working in June 2026, you must register by 5 October 2026. Penalties apply for late registration. Registration is free and takes about 15 minutes via your Government Gateway account. You do not need to wait for approval before you start working — you can trade from day one and register within the required window.
Do I need Gas Safe registration to start a plumbing business?
- Gas Safe registration is only required if you work on gas appliances — boilers, gas fires, cookers, and gas pipework. It is illegal to carry out gas work without Gas Safe registration. If you do general plumbing only (water supply, drainage, central heating without gas), Gas Safe registration is not required. Most plumbers seeking to maximise income will obtain Gas Safe registration. The annual registration fee is approximately £160–£350 depending on how many appliance categories you register for.
What insurance does a self-employed plumber need in the UK?
- Public liability insurance is the most important and is required by most domestic and commercial customers. Minimum £1m cover, though £5m is standard in the industry. Employers' liability insurance is legally required if you employ anyone (even temporary workers). Tools in transit insurance and van insurance (business use) are also highly recommended. Tools can be covered under a tradesperson's tools policy rather than home contents insurance. Annual public liability premiums for plumbers typically range from £150–£500 depending on your turnover.
How much money do I need to start a self-employed plumbing business in the UK?
- Most plumbers starting out already have their tools and qualifications from employed work. The main start-up costs are: van (purchase or lease), insurance (£400–£800 for full cover in year one), Gas Safe registration (£160–£350 if applicable), website and marketing materials (£200–£1,000), and a basic accounting/invoicing setup (TraderInvoice is free to start). Many plumbers start with as little as £500–£2,000 if they already own a van and tools.