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Comparing Company Formations in the UK: Which Business Structure Is Right for You?

The structure you choose when setting up a business in the UK is one of the most consequential decisions you will make. It affects how much tax you pay, what your personal liability is if the business runs into trouble, how you raise money, and how you eventually exit. Getting it right from the start or correcting it as your business grows is worth careful thought, especially during companies formations.

This guide compares the main business formation options available in the UK, explains the tax implications of each, and helps you identify which structure is likely to suit your situation.

The Two Fundamental Categories: Unincorporated and Incorporated

All business structures in the UK fall into one of two broad categories: unincorporated and incorporated. The core difference is legal personality.

Unincorporated: The business has no separate legal identity from its owner(s). You and the business are legally the same. You are personally responsible for all business debts and obligations.

Incorporated: The business is a separate legal person. It can own assets, enter contracts, and incur debts in its own name. Owners have limited liability. In most cases, they can only lose what they have invested.

This distinction has significant practical consequences, particularly if the business fails or is involved in a legal dispute. It also drives most of the tax differences between structures.

Unincorporated Business Structures

Sole Trader

The sole trader is the simplest and most common way to start a business in the UK. You register with HMRC as self-employed and submit an annual self-assessment tax return.

Tax treatment: All profits are treated as your personal income. For 2025–26, you pay:

  • Income tax at 20% on profits between £12,570 and £50,270
  • Income tax at 40% on profits between £50,270 and £125,140
  • Income tax at 45% on profits above £125,140
  • Class 4 NIC at 6% on profits from £12,570 to £50,270, and 2% above

Liability: Unlimited. Your personal assets such as savings, home, and car can be used to settle business debts.

Suitable for: Freelancers, consultants, tradespeople, and anyone starting out who wants minimal administration and whose profits are modest enough that incorporation does not yet make financial sense.

Partnership

A partnership is formed when two or more people run a business together with a view to profit. No formal registration is needed, though a written partnership agreement is strongly advisable, and the business does not need to be registered at Companies House, making it a common option in business formation in UK.

Tax treatment: Each partner pays income tax and National Insurance on their own share of the profits at the same rates as a sole trader. The partnership itself does not pay tax.

Liability: All partners have unlimited liability, which means each partner can potentially be held responsible for the actions and debts of the other partners, not just their own.

Suitable for: Two or more individuals going into business together who want a simple structure and whose profits do not yet justify incorporation.

Limited Partnership

A limited partnership has two types of partner: general partners who manage the business and have unlimited liability, and limited partners whose liability is capped at the amount they have invested and who cannot be involved in day-to-day management. Unlike ordinary partnerships, limited partnerships must register with Companies House.

Suitable for: Specialist investment structures and certain professional arrangements. Rarely the right choice for a straightforward trading business.

Limited Liability Partnership (LLP)

An LLP gives partners limited liability similar to a company while retaining the pass-through tax treatment of a partnership. Members are taxed as self-employed individuals on their profit share and pay income tax and National Insurance through self-assessment. The LLP itself pays no Corporation Tax, making it a popular option in limited company formations decisions.

LLPs must be registered at Companies House, have at least two designated members, and file annual accounts and a confirmation statement.

Suitable for: Professional service firms such as law, accountancy, and architecture where partners want limited liability but prefer the tax treatment and flexibility of a partnership over a company.

Incorporated Business Structures

Private Limited Company (Ltd)

The private limited company is the most common incorporated structure in the UK, used by everything from start-ups to established SMEs with millions in turnover. The company is a separate legal entity. It pays Corporation Tax on its profits, and shareholders pay personal tax on salaries and dividends they receive from it.

If you are not yet fully familiar with how Corporation Tax is calculated and applied, our guide to understanding Corporation Tax covers the essential framework before you make your structure decision.

Corporation Tax rates 2025–26: 19% on profits up to £50,000; 25% on profits above £250,000; with marginal relief applying in between with an effective marginal rate of 26.5%.

Dividend tax rates 2025–26: The first £500 of dividend income is tax-free under the dividend allowance. Above that, rates are 8.75% for basic rate, 33.75% for higher rate, and 39.35% for additional rate.

Liability: Limited to the value of shares held. Shareholders generally cannot be required to contribute more than the amount unpaid on their shares.

Suitable for: Most growing businesses, particularly those with profits above £30,000–40,000 per year, those seeking investment, and anyone who wants to separate personal and business finances clearly.

Public Limited Company (PLC)

A PLC can offer shares to the public and have its shares listed on a stock exchange. This opens access to significantly larger pools of capital but comes with substantially heavier regulatory obligations, including the requirement for a minimum share capital of £50,000 with at least 25% paid up, mandatory audited accounts, and ongoing disclosure requirements.

Suitable for: Established businesses seeking public capital. Not appropriate for the vast majority of SMEs.

Community Interest Company (CIC)

A CIC is a company formed for social or community purposes rather than private profit. It can be limited by shares or by guarantee and benefits from the same limited liability as a standard company. CICs are subject to an asset lock restricting transfer of assets out of the company and a dividend cap.

Suitable for: Social enterprises, charities operating commercial activities, and organisations that want to demonstrate community purpose formally.

Side by Side Comparison

Structure Tax on Profits Personal Liability Admin Burden Best For 
Sole Trader Income tax + NIC on all profits Unlimited Low Simple businesses, low profits 
Partnership Income tax + NIC per partner Unlimited (joint) Low–Medium Two+ people, modest profits 
LLP Income tax + NIC per member Limited Medium Professional firms 
Ltd Company Corporation Tax (19%–25%) + personal tax on extraction Limited Medium–High Growing businesses, profits £30k+ 
PLC Corporation Tax + personal tax on extraction Limited Very High Large businesses, public capital 

 

Which Structure Is Right for You?

If you are just starting out with modest income expectations

A sole trader or simple partnership is usually the right starting point. The administration is straightforward, costs are low, and you can always incorporate later when the numbers make it worthwhile.

If your profits are consistently above £30,000–40,000 per year

At this level, the Corporation Tax rate advantage over income tax starts to become material. A limited company allows you to pay Corporation Tax on profits at 19% if under £50,000 rather than income tax at 40%, and to control when and how you draw personal income. The administrative overhead is greater, but for most people at this profit level, the saving justifies it.

If you are still weighing up whether incorporation is the right move for your specific situation, our guide on whether you should incorporate your business covers the key considerations in detail before you commit to a structure.

If you are a professional working with partners

An LLP gives you the limited liability protection of a company while retaining the tax treatment and flexibility of a partnership. It is the standard structure for accountancy, law, and architecture firms for good reason.

If you are planning to seek investment or sell the business

A limited company is almost always the right structure. Investors and acquirers understand it, can take equity in it, and it provides a clean separation between the business and its founders. If you are already a sole trader and planning an exit, incorporating early gives you time to build the two year ownership record that may be needed to qualify for Business Asset Disposal Relief.

What You Need to Incorporate a Limited Company

Registering a limited company with Companies House requires:

  • A company name that is unique and compliant with naming rules
  • A UK registered office address
  • A Standard Industrial Classification code describing your business activity
  • A Memorandum of Association signed by initial shareholders
  • Articles of Association setting out the company rules
  • Details of all directors, shareholders, and persons with significant control

For a full step-by-step walkthrough of the registration process, our guide on how to register a company in the UK takes you through each stage clearly and in the right order.

You will also be automatically registered for Corporation Tax when you register the company. Make a note of your accounting period end date from the outset, as this determines all your filing and payment deadlines.

Get Help Deciding the Best Structure for Your Business

At Cigma Accounting, we help business owners across London evaluate the right structure for their ventures, whether choosing between sole trader, partnership, or limited company setups. From Fulham Broadway, including Clapham Junction North Side (St John’s Hill) and Battersea Park Perimeter, entrepreneurs often need clarity on liability, tax efficiency, and growth potential, which is why our accounting services London are designed to provide clear, practical direction aligned with your long-term business goals.

Selecting the wrong structure can lead to unnecessary tax exposure or operational limitations, making early advice essential. With physical offices across London, our specialists provide tailored support on company formation accountant London decisions, ensuring your business is structured correctly from the outset and remains fully compliant as it grows.

Frequently Asked Questions

Is a company registration number the same as a VAT number?

No. Your Company Registration Number (CRN) is an 8-digit number assigned by Companies House when your company is formed. Your VAT registration number is a separate 9-digit number issued by HMRC if and when you register for VAT. You must register for VAT if your VAT-taxable turnover exceeds £90,000 in any rolling 12-month period. 

Yes, and it is one of the most common transitions Cigma helps clients with. The process involves incorporating a new company and transferring the business assets and trade to it. Incorporation relief can defer Capital Gains Tax on the transfer of assets if done correctly. Timing and planning matter, it is worth reviewing this with an accountant before making the move. 

Yes. Every limited company must have a UK registered office address, which is publicly displayed on the Companies House register. If you do not have a suitable business address, Cigma can provide a registered office address service using our offices in Wimbledon or Farringdon. 

Most trading companies are limited by shares, meaning shareholders own a stake in the company proportional to their shares and can only lose the amount unpaid on those shares if the company fails. Companies limited by guarantee do not have shareholders; instead, members guarantee to contribute a fixed amount (often just £1) if the company is wound up. This structure is typically used by charities, clubs, and not-for-profit organisations. 

Need Help Choosing the Right Company Structure for Your Business?

Deciding between different business structures can be complex, especially when considering tax implications, personal liability, and future scalability. Our experts at Cigma Accounting provide clear, tailored advice to help you make the right decision from the start. We guide you through each option, ensuring your business is structured efficiently, compliant with HMRC requirements, and positioned for long-term success.

Trusted guidance from London-based accountants, focused on accuracy, clarity, and compliance.