Register a business partnership

When you form a business partnership, you must register with HMRC for Self Assessment. The registration requirements depend on your partnership type, but all partnerships must have a nominated partner who takes responsibility for the partnership's tax affairs.

Who needs to register

Registration is required for:

• The partnership itself - registered by the nominated partner
• Each individual partner - separately registered for their own Self Assessment

Even if you've already registered as a sole trader, you need a separate registration for the partnership.

Registration deadlines

Missing these deadlines results in penalties, so mark them in your calendar as soon as you start trading.

Types of partnership and their registration routes

The registration process differs depending on which type of partnership you're forming.

The nominated partner

Every partnership must have a nominated partner who is legally responsible for the partnership's tax compliance. This is not just an administrative role - the nominated partner faces penalties personally if the partnership tax return is filed late.

Choosing your nominated partner

Partners should agree who will be the nominated partner before registering. Consider choosing someone who:

• Has experience with tax compliance or will engage an accountant
• Is organised and reliable with deadlines
• Will be available to deal with HMRC queries
• Has good communication with all other partners

The nominated partner can change from year to year, but HMRC must be notified of any change.

Registration forms

You'll need specific HMRC forms depending on whether you're registering the partnership or individual partners.

Step-by-step registration process

For general partnerships

1. Agree who will be nominated partner - This person will register the partnership and file annual returns
2. Nominated partner registers the partnership - Complete form SA400 online or by post
3. Wait for partnership UTR - HMRC sends the partnership's Unique Taxpayer Reference within 10-15 working days
4. Each partner registers individually - Using form SA401 (individuals) or SA402 (companies, trusts, LLPs). You'll need the partnership UTR to complete this
5. Wait for individual UTRs - Each partner receives their own UTR for personal tax returns

For limited partnerships (LP)

1. Register with Companies House first - Use form LP5 to register the limited partnership
2. Companies House notifies HMRC - Partnership tax records are set up automatically
3. Each partner still registers separately - Individual partners must still complete SA401 or SA402

For limited liability partnerships (LLP)

1. Register with Companies House - Use form LL IN01 to incorporate the LLP
2. HMRC is notified automatically - No need to register the LLP separately with HMRC
3. Each member registers for Self Assessment - Using SA401 (individuals) or SA402 (corporate members)

Understanding UTR numbers

You'll receive multiple UTR numbers - it's important to understand which is which.

Filing the partnership tax return

Once registered, the nominated partner must file an annual partnership tax return (SA800). This shows total partnership income and how profits are allocated between partners.

What the partnership return contains

The SA800 partnership return includes:

• Total partnership income from all sources
• Allowable business expenses
• Capital allowances claimed
• Each partner's name, UTR, and profit share
• Any changes to partners during the year

Each partner then reports their share on their personal Self Assessment return and pays Income Tax and Class 4 National Insurance on their share.

Late filing penalties

Missing the partnership return deadline triggers penalties that are charged to each partner individually - not to the partnership.

Record keeping requirements

The partnership must keep business records for at least 5 years after the 31 January submission deadline for the relevant tax year. Records to keep include:

• All income and sales records
• All expenses and purchase receipts
• Bank statements and cheque book stubs
• The partnership agreement and any amendments
• Record of each partner's capital contributions and drawings
• Calculations of profit allocation between partners

Getting help with partnership registration