“ An individual or agent can file online the SA100 individual’s tax return, trust return and partnership return. They can register for the service by visiting and selecting `Log in and file your Self-Assessment Tax Return’…Once the customer has successfully registered for the SA Online Service, they will receive an Activation Code. This Code is sent through the post by the Government Gateway within 7 days of enrolment and should arrive within 10 days (21 days if it is being sent abroad). The customer should then log into SA Online and activate the service. The service must be activated within 28 days of the date shown on the Activation Code letter.”