This part of GOV.UK is being rebuilt – find out what beta means

HMRC internal manual

Self Assessment Manual

Records: set up taxpayer record: notification of new business or self employment

This section is for the commencement of a new business or self employment only. New partnerships and partners are covered in SAM100135 and SAM100136.

HMRC requires notification of the commencement of a new business or self employment.

Notification on paper form CWF1

An individual starting a new business or self employment will complete one form only, CWF1 and send the form to the Central Agent Authorisation Team (CAAT) at Longbenton. CAAT deal with all forms CWF1 received and set them all up on SA, apart from the exceptions as stated in SAM100001.

All CWF1 forms should contain a validated national insurance number (NINO). If a validated NINO is not supplied, the form is sent back to the individual explaining that a valid NINO is needed for the form to be processed.

An individual should register as self-employed no later than six months from the end of the tax year they became self-employed. Failure to tell us within the time limit may incur a £100 penalty plus interest. In these cases, the form CWF1 should be processed as normal, and a copy of the CWF1 sent to the relevant Hidden Economy Risk Team (HERT) office, addressed to the Failure to Notify (FTN) section.

If a form CWF1 is returned to your office, please send it to CAAT at Longbenton who will deal with it.

Note: Photocopies of forms CWF1 are not acceptable. CAAT can only process original CWF1 forms.

Notification by other means

When an individual becomes self employed, they must register with HMRC for National Insurance Contributions (NIC) and tax purposes. Other than by completing form CWF1 themselves, they can do this by

  • Calling the Self Employed Registration helpline
  • Registering online via KANA or the Online Tax Registration Service (OTRS)

The Central Authorisation Team (CAAT) process paper forms CWF1 manually for HMRC. From October 2014, registrations received online using the KANA or OTRS methods are dealt with automatically, without manual intervention, unless the case has been noted on a Work Management list as an exception.

Where an attachment is received with the CWF1, CAAT deal with the CWF1 and send the attachment to the processing office to deal with. Examples of such attachments are

  • Claim to repayment
  • Tax returns
  • Claim to reduce payments on account
  • Post indicating the individual is deceased or incapacitated
  • Post that has been redirected from another part of the business


Individuals can register for CIS by

  • Accessing HMRC website
  • Telephoning the helpline for the Newly Self Employed
  • Telephoning CIS Contact Centre
  • Completing a paper version of CIS301, CIS302 or CIS304 and forwarding to CAAT. These forms may be accompanied by CWF1

The CIS Team within the CAAT CWF1 Team receive CIS applications in a number of ways. They can be

  • On their own
  • Attached to a CWF1
  • Received from the Contact Centre

CAAT CWF1 CIS team will only deal with sole trader cases from the Contact Centre. However, if a partnership is mentioned, a CIS304 is sent to the individual.

All CIS forms are checked for a valid NINO or UTR and the form is not complete without one or both of them. The NINO needs to be verified as part of the authentication process. If the NINO cannot be verified, the form will be sent back and the individual will be required to attend an identity check.

If a customer completes a KANA or OTRS registration form and ticks the box confirming they will be working in the Construction Industry, from October 2014, the customer will automatically be registered for CIS without manual intervention, unless the case has been noted on a Work Management list as an exception.