How partners pay tax on profits

When you're in a business partnership, the partnership itself does not pay tax. Instead, each partner pays tax on their share of the profits as if they were running their own business. This is different from how companies are taxed.

You'll need to register for Self Assessment and file a personal tax return each year, even if the partnership also files its own return.

The tax transparency principle

Partnership tax works on what HMRC calls the 'tax transparency' principle. The partnership is treated as transparent for tax purposes - profits flow through to the partners who then pay tax individually.

How your profit share is determined

Before you can calculate your tax, you need to know how much of the partnership profit is allocated to you. This depends on your partnership agreement - and if you don't have one, the Partnership Act 1890 defaults apply.

Common arrangements are:

• equal shares, regardless of work or capital contributed
• fixed percentages, such as a 60/40 split
• priority allocations (like a salary) for some partners, with the remaining profit shared
• shares weighted by capital contributed
• lockstep, where junior partners move up through set shares over time

Whatever arrangement you agree, it must be in place before the accounting period ends. You cannot change allocations retrospectively to reduce tax.

Partner salaries and interest - tax treatment

Many partnership agreements include provisions for partner salaries or interest on capital. It's important to understand that these are not the same as employee salaries or bank interest for tax purposes.

From a tax perspective, partner salaries and interest on capital accounts are simply part of the profit allocation mechanism. They are not deductible expenses for the partnership.

Your tax obligations as a partner

As a partner, you have several distinct tax obligations:

Register for Self Assessment

You must register with HMRC for Self Assessment by 5 October following the end of the tax year in which you became a partner. You'll receive a Unique Taxpayer Reference (UTR) which you'll need for all your tax dealings.

File a personal tax return

Each year, you must file a Self Assessment tax return (SA100) including the partnership pages (SA104S or SA104F). This is in addition to the partnership return filed by the nominated partner.

The deadline is 31 October for a paper return and 31 January for an online return and payment.

Pay Income Tax on your profit share

Your share of partnership profits is taxed as self-employment income. It's added to any other income you have (employment, savings, dividends) and taxed according to the standard Income Tax bands.

Pay National Insurance contributions

As a partner, you pay Class 4 National Insurance based on your profit share. If your profits reach the Small Profits Threshold, Class 2 contributions are normally treated as paid to protect your National Insurance record; below that threshold you can choose to pay voluntary Class 2 contributions.

Payments on account

If your tax bill is over £1,000 and less than 80% of your total tax was collected at source (e.g., through PAYE), you'll need to make payments on account. These are advance payments towards next year's tax bill.

The first payment is due on 31 January, alongside your tax for the year just ended, and the second on 31 July.

Each payment is half of your previous year's tax bill. If your income varies significantly year to year, you can apply to reduce payments on account - but if you underpay, you'll owe interest.

Using partnership losses

If the partnership makes a loss, your share of that loss can potentially be set against your other income to reduce your overall tax bill. However, there are important restrictions, particularly if you're a limited partner or not actively involved in the business.

When partners join or leave

Partnership changes create complexity for tax purposes. When a partner joins or leaves mid-year, their profit share is calculated based on the period they were actually a partner.

Record keeping

As a partner, you must keep records of:

• Your capital contributions to the partnership
• Drawings you've taken from the partnership
• Your share of profits as shown in the annual accounts
• Any expenses you've incurred personally on behalf of the partnership

Keep these records for at least 5 years after the 31 January submission deadline for the relevant tax year.