A contractor is a worker who sells services to clients through their own business rather than through an employer’s payroll. Becoming a contractor in the UK takes 3 steps: choose a working structure, complete the registrations in order, then arrange the practical items before the first contracting client signs. Moving from freelance to contract work follows the same 3 steps as moving from employment. Every fact below is drawn from GOV.UK, verified 19 September 2026.
What Are the Ways to Work as a Contractor?
Contractors in the UK work through 3 routes: sole trader, limited company or umbrella company. Each route changes who invoices the client, who runs the payroll and which taxes apply.
The 3 routes work as follows:
- Sole trader. You register as self-employed, invoice clients directly and report profit through Self Assessment. Setup carries no incorporation fee and one annual tax filing.
- Limited company (a personal service company, PSC). Your company signs the contract with the client, pays Corporation Tax on its profit, and you draw a salary plus dividends from the company.
- Umbrella company. You become the umbrella’s employee. The umbrella invoices the client, runs PAYE on your pay and charges a margin for the service. Employment benefits attach, with no company of your own to run.
Typical fits: an umbrella suits short engagements or inside-IR35-only work; sole trading suits low-risk business-to-business services; a limited company suits sustained outside-IR35 contracting. IR35 is the legislation that taxes some engagements as employment, so it shapes the choice at every step.
Which Structure Suits a First-Time Contractor?
The structure that suits a first-time contractor follows 5 inputs: income level, client requirements, IR35 exposure, liability and admin load.
Income level. Corporation Tax runs at 19% on company profits up to £50,000 and 25% above £250,000, with marginal relief between the two thresholds. Dividends above the £500 allowance are taxed at 10.75%, 35.75% or 39.35%. Sole traders pay Income Tax at 20%, 40% or 45% plus Class 2 and Class 4 National Insurance. At lower billing, sole trading’s simplicity wins; as profit rises, the company route usually outperforms. How much salary and how much dividend to draw is a separate calculation inside the company route.
Client requirements. Agencies and end clients often require a limited company or an umbrella arrangement, which removes sole trading from the choice before tax even enters it. The umbrella vs limited company question then turns on the length of the work and its IR35 status.
IR35 exposure. Contractors whose engagements sit inside IR35 gain little from a PSC, because the engagement is taxed as employment anyway.
Liability. A limited company limits personal liability to the company’s assets. Sole traders carry business liabilities personally.
Admin load. A company brings annual accounts, a confirmation statement, PAYE and Corporation Tax. A sole trader files one Self Assessment.
Incorporation runs through our limited company formations service, and sole traders file through our self-employed and sole trader accounts service.
The table below compares the 3 routes across tax filings, liability and typical fit for a first-time contractor.
| Structure | Tax filings | Liability | Typical fit |
|---|---|---|---|
| Sole trader | One Self Assessment, due 31 January | Personal, unlimited | Lower billing, low-risk B2B services |
| Limited company (PSC) | Company accounts, Corporation Tax, PAYE, confirmation statement | Limited to company assets | Sustained outside-IR35 contracting |
| Umbrella company | None personal; the umbrella runs PAYE | Employment rights attach | Short or inside-IR35-only engagements |
What Registrations Does a New Contractor Need?
A new contractor completes 4 registrations in order: Self Assessment, incorporation and Corporation Tax, PAYE, then VAT or CIS where the work triggers them (GOV.UK, verified 19 September 2026).
Contractor tax registration runs in this sequence:
- Sole trader route: register for Self Assessment. The deadline is 5 October after the first full tax year of self-employment. HMRC posts a Unique Taxpayer Reference (UTR), and the return plus any tax due land by 31 January. Class 2 National Insurance for sole traders is collected through the same Self Assessment.
- Limited company route: incorporate and register the company. Incorporation at Companies House costs £34 online. The company registers for Corporation Tax within 3 months of starting to trade. PAYE registration precedes the first payday, even in a solo-director company paying one small salary.
- VAT registration. Registration is required when VAT taxable turnover passes £90,000 in a 12-month period. Voluntary registration earlier is allowed.
- CIS registration. Construction work triggers the Construction Industry Scheme, and duties exist on both the contractor side and the subcontractor side of a payment.
What Should You Sort Before the First Contract?
Before the first contract, sort 6 items: the IR35 position, the rate, payment terms, a business bank account, insurance and an accountant.
- The IR35 position. Check the engagement’s IR35 status and how the client determines it. Medium and large clients issue a Status Determination Statement (SDS) for each engagement.
- The rate. Confirm the rate covers the costs employment normally carries: holiday pay, sick pay, pension contributions and employer National Insurance. Inside IR35, the fee-payer deducts these costs from the rate.
- Payment terms and expenses. Agree payment terms in the contract before signing. Contractor expenses, the tax-deductible costs of running the contract such as travel and equipment, sit alongside those terms.
- A business bank account. A company requires a business bank account. A sole trader benefits from one, and CIS gross payment status lists a business bank account among its conditions.
- Insurance. Professional indemnity and public liability cover are the 2 contractor insurance types clients most commonly require before a contract starts.
- An accountant. Engage an accountant before the first invoice, not at the first tax bill. The structure decision is the expensive one to get wrong. Our contractor accountants in Newcastle team handles structure, registrations and the first year of filings as one package.
Common Questions Answered
Is it better to start contracting as a sole trader or a limited company?
Sole trading is simpler; a limited company is more tax-efficient above roughly £30,000 to £40,000 of annual billing. Sole trader setup is free through GOV.UK, with simpler accounts and one Self Assessment. A limited company pays Corporation Tax at 19% or 25% and draws income through salary plus dividends, and the crossover point depends on each person’s numbers. Many clients and agencies prefer or require a limited company or umbrella arrangement regardless of tax.
Do I need to register for VAT as a contractor?
VAT registration applies only when VAT taxable turnover exceeds £90,000 (GOV.UK, verified 19 September 2026). Voluntary registration below the threshold suits contractors with VAT-registered clients who reclaim the input VAT on their costs. The Flat Rate Scheme is an option some small contractors use; eligibility checks belong with an accountant.
How much does a contractor pay in tax compared to an employee?
No guaranteed saving exists; the total depends on profit level, IR35 status and the Employment Allowance position. Inside IR35, engagements are taxed like employment, with the fee-payer deducting Income Tax and National Insurance. Outside IR35, a limited company contractor pays Corporation Tax at 19% to 25%, Income Tax on salary, and dividend tax at 10.75%, 35.75% or 39.35% above the £500 allowance.
Can I start contracting while still employed?
Yes, employment and contracting run together. Check the employment contract for exclusivity or side-business clauses first; that check is contract law, not tax. The additional income is reported through Self Assessment, and a PAYE salary interacts with contract income through the tax code. Registration with HMRC is due by 5 October after the first tax year with untaxed income (GOV.UK, verified 19 September 2026).
How Aqua Accounting Can Help
Aqua Accounting turns the decision to become a contractor into a working setup: structure advice matched to the billing level, the registrations filed in order, and the first contract reviewed before signature. The firm is an ICAEW Registered Member Firm of Chartered Accountants, with 13+ years serving North East businesses from a UK-based team in Newcastle upon Tyne.
Book a consultation and start contracting with the structure, the registrations and the first contract arranged correctly.
Disclaimer:
The information provided in this blog is for general informational purposes only and does not constitute professional advice. While every effort is made to ensure accuracy, Aqua Accounting accepts no responsibility for any actions taken based on this content. You should seek professional advice tailored to your individual circumstances.
Omar Ahmed is an ICAEW Chartered Accountant and the Director of Aqua Accounting, a UK-based accountancy practice providing expert accounting and tax services to individuals, sole traders, and small to medium-sized businesses. As a trusted accountant in Newcastle, he offers expertise in annual accounts, self-assessment tax returns, company accounts, VAT, payroll, bookkeeping, and company formation.
With a strong focus on delivering clear and practical financial advice, Omar helps clients stay compliant while improving their understanding of their finances. Through Aqua Accounting, he works closely with business owners to simplify accounting processes, meet tax obligations, and support informed financial decision-making.