EM1991 - Working the Enquiry: Closure Applications: Consequences of Tribunal Decision on Other Years
The giving of a tribunal’s direction in respect of a year does not extend to other years (unless a direction is also given for those years, where the return is the subject of an SA notice).
If you have already extended your enquiries into earlier years� returns (whether for a pre-SA year, an SA year or a mixture of both) you can continue to pursue those enquiries.
If however you have not yet discussed earlier years� liabilities with the taxpayer or agent, you should only do so following a direction if the conclusions you have already been able to draw about the return under enquiry cast doubts on the accuracy of earlier years� returns, or if you could make a discovery assessment on the basis of other information relating to those years which is in your possession.