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HMRC internal manual

Self Assessment Manual

Records: set up taxpayer record: forms for registering partnerships and partners

From 25 October 2010, there are three new forms for partnerships and partners to register for Self Assessment (SA) and where appropriate, Class 2 National Insurance Contributions (NICs).

From the same date, there is a change to the process of registering for SA where the partnership is a limited liability company (LLP) or a limited partnership (LP). These two types of partnership must register with Companies House and with effect from 25 October 2010, registration for SA will take place automatically from the Companies House data. Ordinary partnerships are not affected by this process change as they do not have to register with Companies House but there is a new form for them to complete detailed below.

Initially the new forms are targeted at tax agents. There is no reason though why unrepresented partnerships and partners should not use the new forms; it is just that it will take a couple of months to update the online guidance to this effect. Until then, the guidance will still direct customers to form CWF1, so this form will still be accepted too for a short time. Once the online guidance is amended, form CWF1 will only be applicable to sole traders.

New forms and guidance

SA400 - Registering a partnership for Self Assessment

Form SA400 is to be used to register a partnership for SA purposes. The form should be completed by the nominated partner that is, the partner nominated by the partnership to receive and submit the partnership returns, see subject ‘Maintain Taxpayer Record: Nominated Partner’ (SAM101290).

LLP and LP only need to complete this form if they registered with Companies House before 25 October 2010. LLP and LP will be automatically registered for SA using the Companies House data from 25 October 2010.

An example of how to use this new form: Where say a wife joins her husband in partnership thus creating a new partnership, a form SA400 should be completed for the partnership in addition to forms SA401 (the new registration form for partners) for both the husband and the wife.

Customers should send forms SA400 to HMRC together with forms SA401 and SA402 and any forms 64-8.

SA401 - Registering a partner for Self Assessment and Class 2 NICs

Form SA401 is to be used to register an individual joining a partnership for SA and Class 2 NICs and will be applicable to all new partners including the nominated partner.

SA402 - Registering a partner for Self Assessment if they’re not an individual

Form SA402 is to be used to register a partner for SA when they are not an individual, for example a company, partnership or a trust.

Completed forms

All completed forms including forms 64-8 should be sent to

National Insurance Contributions and Employer Office
Self-employment and Self Assessment Registrations
Benton Park View
Newcastle upon Tyne

NE98 1ZZ

Shortened information on a spreadsheet

By individual agreement with Central Agent Authorisation Team (CAAT), a spreadsheet can be used to notify changes if the number of new partners warrants it, if the partnership is already in existence and all new partners already have a unique taxpayer reference (UTR) and are registered for Class 2 NICs.

For ease of input, the heading shown below must be shown as the title of the table and all the following information is mandatory and must be provided in the order set out below. The smallest font size used must be Times New Roman 12 point and the spreadsheet must be signed by the nominated partner for the partnership.

Spreadsheet heading

‘Partners who already have a UTR and are already registered for Class 2 NICs joining this partnership’.

Spreadsheet mandatory sub headings

a. Name of partnership for HMRC purposes (as recorded at Companies House from 18/10/10 if applicable).
b. Address of partnership for HMRC purposes (as recorded at Companies House from 18/10/10 if applicable).
c. The partnership’s unique taxpayer reference (UTR).

Data for each partner


First name

Date of birth




Date of joining partnership