If you run a business as a partnership, you must file two types of tax return each year: the SA800 Partnership Tax Return for the partnership itself, and an SA100 Self Assessment return for each individual partner.

The partnership return reports the overall business income, expenses, and profit. Each partner then reports their allocated share on their personal tax return.

How partnership taxation works

Partnership tax transparency principle

How partnerships are taxed - profits taxed on individual partners, not the partnership.

A partnership is not separately taxable. Partnership profits are taxed on the individual partners, not on the partnership itself. This is known as the tax transparency principle.

Partners are generally taxed in the same way as other businesses conducted by sole traders or companies, depending on partner type.

Individual partners: Pay Income Tax and National Insurance on their share of profits
Corporate partners: Pay Corporation Tax on their share of profits
Registration deadline: By 5 October in the partnership's second tax year

Who must file

You must file an SA800 partnership return if your business is a:

General partnership - two or more people trading together
Limited liability partnership (LLP) - registered at Companies House
Limited partnership - with at least one general partner and one limited partner

The partnership must file even if it made a loss during the tax year.

The nominated partner

One partner must be designated as the nominated partner who takes responsibility for the partnership's tax affairs.

Nominated partner responsibilities

Definition and duties of the nominated (representative) partner for tax purposes.

The nominated partner (also called the representative partner) is chosen by the other partners to manage the partnership's tax affairs. This is a legal requirement under Section 12AA(2) of the Taxes Management Act 1970.

Main responsibility: Complete and file the partnership tax return (SA800)
HMRC liaison: Act for the partnership on returns, claims, and enquiries
Record keeping: Manage business records for tax purposes
Partner communication: Keep other partners informed of HMRC enquiries
Liability: Responsible if documentation is filed late

If partners cannot agree on a nominated partner, HMRC will nominate the first active (non-sleeping) partner alphabetically. The nominated partner may differ for each accounting period.

Registration requirements

Before you can file, the partnership and each partner must be registered for Self Assessment.

Partnership Self Assessment registration

Registration forms and deadlines for partnership Self Assessment.

Partnership registration form: SA400
Individual partner registration form: SA401
Company/partnership partner registration form: SA402
Registration deadline: 5 October following the end of the partnership's first tax year
UTR processing time: Approximately 28 working days by post

LLPs and Limited Partnerships are automatically registered for Self Assessment through Companies House registration - no SA400 required. Each partner must also register individually and receive their own UTR.

Register a partnership for Self Assessment

Filing deadlines

The SA800 partnership return has the same deadlines as individual Self Assessment returns.

SA800 Partnership Tax Return deadlines

Key filing deadlines for partnership Self Assessment tax returns.

Paper return deadline: 31 October following the end of the tax year
Online return deadline: 31 January following the end of the tax year
Example: 2024/25 tax year (paper): 31 October 2025
Example: 2024/25 tax year (online): 31 January 2026

Partnerships must file form SA800 even if the partnership made a loss. HMRC does not provide free online filing for SA800 - commercial software is required for online submission.

Supplementary forms

Depending on the size and complexity of your partnership, you may need additional forms.

SA800 supplementary pages

Additional forms required with the SA800 Partnership Tax Return.

Short Partnership Statement: Included in SA800 - caters for up to 3 partners
SA800(PS) - Full Partnership Statement: Separate supplementary pages for more than 3 partners (up to 6)
SA800(TP) - Trading and Professional Income: For partnerships with income from more than one trade or profession
SA804 - Savings, Investments and Other Income: For partnership savings, investments and other non-trading income

Individual partners must also complete SA104 supplementary pages with their personal SA100 tax return. Use SA104S (short) for trading income and bank interest only, or SA104F (full) for other types of partnership income.

Download SA800 Partnership Tax Return

Individual partner returns

Each partner must also file their own SA100 Self Assessment return, declaring their share of the partnership profits along with any other income they receive.

What partners must report:

Their allocated share of partnership profits or losses (from the Partnership Statement)
Any other personal income (employment, savings, dividends, rental income)
Any personal tax reliefs or allowances

SA104 supplementary pages: Partners complete form SA104 with their personal return to report partnership income:

SA104S (Short): For trading income and bank interest only
SA104F (Full): For other types of partnership income (property, foreign income, etc.)

The profit share shown on your SA104 must match exactly what's in the partnership's SA800 Partnership Statement.

Partnership profit allocation

Partnership profit sharing rules

Rules governing how partnership profits and losses can be allocated between partners.

Partners have flexibility in how they share profits and losses. The sharing ratio need not be in proportion to contributions of effort or capital.

Profit sharing flexibility: Profits, losses, or other income may be shared as partners mutually agree
Different ratios allowed: Profits and losses need not be shared in the same proportions
No retrospective changes: Allocation cannot be varied after the accounting period ends (Bucks v Bowers 1969)
Commercial basis: Tax-adjusted profits allocated according to commercial profit-sharing arrangement in force

Key constraint: The allocation must represent a straight apportionment of the actual partnership profit or loss. An allocation must not create or increase a loss - partners cannot collectively receive allocations that exceed or fall short of the actual partnership position.

National Insurance for partners

Individual partners pay National Insurance as self-employed individuals based on their share of partnership profits.

Partner National Insurance rates 2026/27

Class 2 and Class 4 National Insurance rates for partners as self-employed individuals.

Class 2 threshold: £6,845 per year
Class 2 treatment: Treated as paid automatically if profits exceed threshold
Class 2 voluntary rate: £3.50 per week (to protect NI record if below threshold)
Class 4 lower profits limit: £12,570 per year
Class 4 upper profits limit: £50,270 per year
Class 4 main rate: 6% on profits between £12,570 and £50,270
Class 4 additional rate: 2% on profits over £50,270
Effective from: 6 April 2025

Partners pay National Insurance as self-employed individuals based on their share of partnership profits. Contributions are paid through the Self Assessment tax return.

Self-employed National Insurance rates

Late filing penalties

If you miss the filing deadline, penalties apply to the partnership and accumulate the later you file.

SA800 late filing penalties

Penalty structure for late partnership tax return filing.

Initial late filing penalty: £100
3 months late (daily penalty): £10 per day, up to maximum £900
6 months late: 5% of tax due or \u00A3300, whichever is greater
12 months late: Additional 5% of tax due or \u00A3300, whichever is greater
Penalty liability: All partners are liable, not just the nominated partner

Penalties are charged to the partnership. The 6-month and 12-month penalties are additional to earlier penalties, meaning total penalties can accumulate significantly for very late returns.

Late payment penalties

Partners pay tax individually through their personal Self Assessment. If payment is late, penalties apply to the individual partner.

Partnership tax late payment penalties

Penalty structure for late payment of partnership-related tax.

30 days late: 5% of tax unpaid
6 months late: Additional 5% of tax unpaid
12 months late: Additional 5% of tax unpaid
Penalty notice payment deadline: 30 days from the date on the penalty notice

Late payment penalties apply to individual partners on their personal tax liability. Each partner is responsible for paying tax on their allocated share of partnership profits through their own Self Assessment.

When partners join or leave

Changes to the partnership during the tax year affect how profits are allocated and reported.

Partner joining and leaving - tax treatment

How the tax position is calculated when partners join or leave a partnership.

New partner notional trade start: Later of: when they joined the partnership, or when partnership started trading
Leaving partner notional trade end: Earlier of: when they leave, or when partnership ceases trading
Complete ownership change: Business treated as having ceased and recommenced
Partial ownership change: Business treated as continuing
Partner to sole trader: Notional trade continues until actual business permanently stops

These rules are set out in Sections 852-856 of the Income Tax (Trading and Other Income) Act 2005.

Loss relief restrictions

If your partnership makes a loss, there are restrictions on how certain types of partners can use that loss.

Partnership loss relief restrictions

Restrictions on sideways loss relief for limited partners, LLP members, and non-active partners.

Sideways loss relief (setting partnership losses against other income) is restricted for certain types of partners.

Applies to: Limited partners, non-active LLP members, non-active general partners
Capital contribution limit: Sideways relief cannot exceed capital contribution at risk of loss
Annual limit: £25,000 per tax year (after capital contribution limit applied)
Annual limit effective from: 2 March 2007
Carry forward: Restricted losses can be carried forward against future partnership profits

What does not count as capital contribution:

Guarantees of partnership borrowing
Loans made to the partnership
Contributions financed through non-recourse loans

Purpose test: Capital contributions paid on or after 2 March 2007 do not count if the main purpose is to obtain sideways loss relief (applies to non-active partners only).

1

Register the partnership

Complete form SA400 if you're a general partnership. LLPs and Limited Partnerships are registered automatically through Companies House.
2

Register each partner

Each partner must complete form SA401 (individuals) or SA402 (companies/partnerships) to get their own UTR.
3

Appoint a nominated partner

Designate one partner to receive and file partnership tax returns and handle HMRC correspondence.
4

Keep partnership records

Maintain business records for at least 5 years - income, expenses, assets, liabilities, and profit allocations.
5

Calculate profit allocations

Work out each partner's share of profits or losses according to your partnership agreement.
6

File SA800 partnership return

Submit by paper (31 October) or online using commercial software (31 January).
7

Provide partners with their allocations

Give each partner their profit/loss share so they can complete their personal return.
8

Each partner files SA100

Partners file their personal Self Assessment by 31 January, including SA104 supplementary pages.
9

Pay tax individually

Each partner pays Income Tax and National Insurance on their share by 31 January.

LIMITED LIABILITY PARTNERSHIP Requirement

LLPs have additional filing requirements

Limited liability partnerships have additional obligations:

Annual accounts: File accounts with Companies House (same deadline as limited companies)
Confirmation statement: Annual filing to confirm LLP details are correct
Members' register: Maintain a register of members (partners)

LLP members are still taxed as partners (not employees), paying Income Tax and National Insurance on their profit share through Self Assessment.

Comparison to other structures:

LLPs combine limited liability protection with partnership taxation. They must comply with both Companies House filing and HMRC Self Assessment requirements.

When this matters: When you need limited liability but want pass-through taxation

Running a limited liability partnership

Register a partnership for Self Assessment

File partnership tax returns (SA800)

How partners pay tax on profits

Register a business partnership

Prepare for Making Tax Digital

Register for Self Assessment

Filing your Self Assessment tax return

How partnership taxation works

Who must file

The nominated partner

Registration requirements

Filing deadlines

Supplementary forms

Individual partner returns

Partnership profit allocation

National Insurance for partners

Late filing penalties

Late payment penalties

When partners join or leave

Loss relief restrictions

Register the partnership

Register each partner

Appoint a nominated partner

Keep partnership records

Calculate profit allocations

File SA800 partnership return

Provide partners with their allocations

Each partner files SA100

Pay tax individually

LLPs have additional filing requirements

Comparison to other structures:

Related guides in Business Structure

How partnership taxation works

Who must file

The nominated partner

Registration requirements

Filing deadlines

Supplementary forms

Individual partner returns

Partnership profit allocation

National Insurance for partners

Late filing penalties

Late payment penalties

When partners join or leave

Loss relief restrictions

Register the partnership

Register each partner

Appoint a nominated partner

Keep partnership records

Calculate profit allocations

File SA800 partnership return

Provide partners with their allocations

Each partner files SA100

Pay tax individually

LLPs have additional filing requirements

Comparison to other structures: