SA104 partnership pages: short (SA104S) or full (SA104F)?

Who needs it

• Every partner in a business partnership: HMRC requires partners to send a Self Assessment return.
• SA104S: partners whose only partnership income was trading income, plus interest or alternative finance receipts taxed by a bank or building society.
• SA104F: partners who don't qualify for the short version. It covers every type of partnership income.
• Not the partnership itself. The partnership's return is the SA800.

What you need before you start

• Your UTR.
• Your share of the partnership's profit or loss and taxed interest, from the partnership statement the nominated partner prepares with the SA800.
• Details of any other income for the rest of your SA100.

How to file SA104

1. 1Register as a partner on form SA401 if you haven't sent a return before. It registers you for Self Assessment and Class 2 National Insurance.
2. 2Get your share of the figures from the nominated partner once the partnership's SA800 is prepared.
3. 3Check whether the short page applies: only trading income and taxed bank or building society interest.
4. 4Enter your share in the partnership section of your online return, or complete SA104S or SA104F and send it with your paper SA100.

Short or full

HMRC's test for the short page is narrow: you're only declaring partnership trading income and interest or alternative finance receipts that a bank or building society has already taxed. If that's all, SA104S is two pages.

Anything beyond that, such as partnership property income, foreign income or chargeable gains, needs the full pages, SA104F. HMRC describes the full version as covering all the possible types of partnership income.

How SA104 and SA800 fit together

A partnership files two layers of return. The nominated partner, who is responsible for the partnership's tax returns and records, sends the SA800 Partnership Tax Return for the business as a whole. That return includes a partnership statement splitting the profit between the partners.

Each partner then reports their own share on SA104 within their personal SA100. The tax is charged on the partner, not the partnership.

Registering as a partner

Partners register on form SA401, which covers both Self Assessment and Class 2 National Insurance. If you're the nominated partner you must also register the partnership. The 5 October deadline applies as it does for anyone new to Self Assessment.

Common mistakes

• Putting partnership profits on the self-employment pages. Partners use SA104, not SA103.
• Using the short page with income other than trading income and taxed interest. Anything else needs SA104F.
• Assuming the SA800 covers you. The partnership return reports the business; each partner still files their own return.
• Filing before the partnership figures are final, so your share doesn't match the partnership statement.