File your partnership tax return (SA800)

The SA800 tells HMRC what the partnership earned and how that income is shared. It is not a tax bill. Each partner then reports their share on their own tax return and pays the tax on it.

Check who must file and when

HMRC asks a partnership to file by sending a notice to the partners. The return covers a partnership governed by the Partnership Act 1890, a limited partnership and a limited liability partnership (LLP). It applies whether or not the partnership made a profit. An LLP that does not carry on a business with a view to profit, or is being formally wound up, may need a Corporation Tax return instead.

Register the partnership and each partner

The nominated partner registers the partnership for Self Assessment using the online service or form SA400. Each partner registers separately and gets their own Unique Taxpayer Reference. The nominated partner can register partners online, while a partner who is not the nominated partner must register by post using form SA401. HMRC usually replies within 15 days. Register by 5 October in the partnership's second tax year, or you risk a penalty.

Choose a nominated partner

The other partners choose the nominated partner. If they do not choose, HMRC can nominate one. All partners remain responsible for the accuracy of the return, so each should check it before it goes in.

Complete the return

Every partnership gets the first eight pages of the return, which cover trading and professional income and interest from banks and building societies. Answer every question on them and add the supplementary pages that apply.

The partnership also uses SA801 for UK property income, SA802 for foreign income and SA803 for disposals of chargeable assets. The return covers accounting periods that end in the tax year. A change of partners does not end the partnership's business for tax, but the partner details and profit shares must show who was a partner for which part of the year.

Fill in the Partnership Statement to show each partner's share of profits, losses and other income. If your partners are a mix of individuals and companies, or include non-residents, you may need more than one statement. Keep the financial records for at least five years after the 31 January filing deadline and show them to HMRC if it asks.

File by the deadline

You may have longer if HMRC gave you notice after 31 July or if the partnership includes a company as a partner. To file online, register for the online service and buy commercial software. You can file online even if HMRC sent you a paper return. Send the return as early as you can, because the partners cannot finish their own returns without their figures.

Give partners their figures

Send each partner a copy of the Partnership Statement as soon as the return is ready. They use it to complete the partnership pages of their own Self Assessment return. Each partner pays the tax on their own share through their own Self Assessment account, and the balance is due by 31 January. A partnership can make one payment for several partners only if it states how the payment is split.

Avoid late filing penalties

If the lateness delays the partners' own returns, they face their own penalties too.

Know what happens after you file

HMRC usually has 12 months from the day it receives the return to open an enquiry, and it may ask for the records behind your figures. If you find a mistake after filing, or figures change, tell HMRC at once, because it may otherwise charge a penalty. Where the return is wrong through lack of reasonable care, each partner can face a penalty of 30% to 100% of the extra tax due on their share.