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How to Vet a UK Contractor: Complete Checklist for 2025

15 Point Verification Process Before You Hire

10 min read
~2,000 words
Updated December 2025

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Complete all 15 checks before making a hiring decision.

A bad contractor can turn a £15,000 kitchen renovation into a £25,000 nightmare. Unfinished work, poor craftsmanship, and contractors who vanish mid project cost UK homeowners an estimated £1.4 billion annually.

The good news? Most of these disasters are preventable with proper vetting. This systematic 15 point checklist helps you find the right professional for your project, whether you are hiring for a bathroom refit, full house renovation, or energy retrofit.

The Cost of Not Vetting

Citizens Advice reports home improvement complaints consistently rank in their top 10 consumer issues. The most common problems:

  • 38% Work not completed to acceptable standard
  • 22% Contractor abandoned project mid way
  • 19% Final cost significantly exceeded quote
  • 15% Work took much longer than promised
  • 6% Contractor disappeared after taking deposit

Average loss when proper vetting is skipped: £5,000 to £10,000. Some homeowners lose £50,000+ on major projects.

Priority Guide:
Essential: Must verify before hiring
Important: Strongly recommended
Recommended: Good practice

Section 1: Basic Credentials

Points 1 to 5 of your vetting checklist

1. Verify Business RegistrationEssential

Every legitimate contractor should be a registered business. Check Companies House for limited companies, or ask for their UTR number for sole traders.

How to Verify

Search company name on Companies House. Verify company status is 'Active', directors match who you are dealing with, and note how long they have been trading.

Companies House (free search at find-and-update.company-information.service.gov.uk)

Red Flags

Company is dissolved, dormant, or does not exist. Directors do not match. Very recently incorporated with no track record.

2. Confirm Fixed Business AddressEssential

A legitimate contractor has a fixed business address, not just a mobile number. This matters because you need to find them if something goes wrong.

How to Verify

Check address matches Companies House registration. Use Google Street View to verify it is a real premises rather than a virtual office or PO Box.

Red Flags

Only provides mobile number. Address is a virtual office or residential property. Address does not match official registration.

3. Check Trade Body MembershipImportant

Trade body membership signals commitment to standards. Members agree to codes of practice and often carry additional guarantees.

How to Verify

Search the relevant trade body website with the contractor's name or registration number. Call to confirm membership is current.

FMB for builders, NICEIC/NAPIT/ELECSA for electricians, Gas Safe for gas engineers, TrustMark for retrofit

Red Flags

Claims membership but not listed on trade body website. Membership lapsed or under investigation.

4. Verify Public Liability InsuranceEssential

Public liability insurance covers damage to your property or injury to third parties. Minimum cover should be £2 million for domestic work.

How to Verify

Request certificate of insurance. Call the insurer directly to verify policy is current and covers the type of work you need.

Red Flags

Cannot produce certificate. Policy expired. Cover amount too low. Policy excludes the work type you need.

5. Confirm Employers Liability InsuranceEssential

Required by law if they have employees. Covers workers injured on your property. Without it, you could be held liable.

How to Verify

Request certificate showing minimum £5 million cover. Verify policy is current and covers all workers on site.

Red Flags

Claims to work alone but brings helpers. Cannot produce certificate. Policy does not cover subcontractors they use.

Section 2: Track Record

Points 6 to 10 of your vetting checklist

6. Request ReferencesEssential

Ask for at least three references from similar projects completed in the last 12 months. Quality contractors have satisfied customers willing to vouch for them.

How to Verify

Actually call references. Ask about timeline, budget accuracy, quality of work, communication, and whether they would hire again.

Red Flags

Cannot provide references. References are vague or cannot recall details. All references are family or friends.

7. View Portfolio of Past WorkImportant

Ask to see photos of completed projects similar to yours. Look for before and after images showing the transformation.

How to Verify

Request photos with dates. Ask to visit a recent completed project if possible. Check their website and social media.

Red Flags

No photos available. Stock images on website. Cannot show projects similar to yours.

8. Check Online ReviewsImportant

Look at Google reviews, Checkatrade, Rated People, TrustATrader, and Facebook. Multiple sources give a fuller picture.

How to Verify

Read reviews from multiple platforms. Look for patterns in complaints. Note how they respond to negative reviews.

Red Flags

No online presence. Only 5 star reviews (may be fake). Defensive or aggressive responses to criticism. Pattern of similar complaints.

9. Years in BusinessRecommended

Longer established businesses generally carry lower risk. Check how long they have been operating under current name.

How to Verify

Companies House shows incorporation date. Ask directly how long they have been in the trade (may be longer than current company).

Red Flags

Brand new company with no track record. Multiple company names over short period. Previous companies dissolved.

10. Specialist ExperienceImportant

Verify they have specific experience with your type of project. A bathroom specialist may not be ideal for structural work.

How to Verify

Ask how many similar projects they have completed. Request specific examples and references for your project type.

Red Flags

Generalist claiming expertise in everything. Cannot demonstrate relevant experience. First time doing your type of work.

Section 3: Quote Quality

Points 11 to 15 of your vetting checklist

11. Written Quote with Full SpecificationEssential

Quote should detail exactly what is included, what is excluded, materials to be used, and timeline. Vague quotes lead to disputes.

How to Verify

Read every line. Ask about anything not explicitly mentioned. Clarify whether VAT is included. Understand payment terms.

Red Flags

Verbal quote only. Vague descriptions like 'bathroom as discussed'. No timeline. Excludes key items.

12. Clear Payment ScheduleEssential

Payments should be tied to completed milestones, not calendar dates. Never pay more than 20% deposit.

How to Verify

Payment schedule should show: 10% to 20% deposit, stage payments at completion of major phases, 10% retention until snagging complete.

Red Flags

Wants 50%+ upfront. Payments not linked to work stages. Cash only. Reluctant to put payment terms in writing.

13. Compare Three QuotesEssential

Always get at least three quotes for comparison. This establishes market rate and reveals outliers.

How to Verify

Ensure quotes are for identical scope. Compare line by line. Ask contractors to explain significant differences.

Red Flags

Quote dramatically lower than others (corners will be cut). Quote dramatically higher without justification. Reluctant to provide detailed breakdown.

14. Contract TermsEssential

A written contract protects both parties. It should cover scope, timeline, payment, variations, and dispute resolution.

How to Verify

Review contract carefully before signing. Ensure it matches the quote. Check cancellation terms and warranty provisions.

Red Flags

No written contract. One sided terms. No provisions for variations or disputes. Pressure to sign immediately.

15. Warranty and GuaranteesImportant

Understand what warranties apply to workmanship and materials. Check if covered by insurance backed guarantee schemes.

How to Verify

Get warranty terms in writing. Check duration and what is covered. Verify if registered with deposit protection or guarantee scheme.

Red Flags

No warranty offered. Verbal promises only. Warranty shorter than industry standard. No comeback if company fails.

Trade Body Reference Guide

Different trades have different relevant accreditation bodies. Use this guide to verify credentials for specific work types.

Key UK trade accreditation bodies
TradeKey AccreditationsWhat It Means
General BuilderFMB (Federation of Master Builders)Vetted, insured, code of practice
ElectricianNICEIC, NAPIT, ELECSACompetent Person Scheme: can self certify
Gas EngineerGas Safe RegisterLegally required for any gas work
PlumberCIPHE, WaterSafeTrained to regulations, often not mandatory
RooferNFRC, Competent RooferInsurance backed guarantees available
Retrofit/InsulationTrustMark, PAS 2030Required for government grant funding

Key Takeaways

Use all 15 points. Skipping checks is how problems start.
Verify Companies House registration and insurance independently.
Actually call references. Do not just accept a list of names.
Everything in writing. Verbal agreements are worthless in disputes.
Never pay more than 20% deposit. Tie payments to milestones.
Get three quotes. Compare scope carefully, not just price.

Know What to Pay Before You Get Quotes

Use our free calculator to understand fair pricing so you can identify overpriced or suspiciously cheap quotes.

Use Cost Calculator

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This checklist is for guidance only. Always conduct your own due diligence and consider professional advice for major projects.