Losses in trade can be set against other income of the same year. Normally the self-assessment returns procedure would be followed TR1 to register for self-assessment, file Forms 11 for the years concerned once registered. Then de-registration. The losses would be allowable at the taxpayers marginal rate. Self-assessment means that all records must be available for possible Revenue Audit and must be retained for the statutory perriod of 6 years. ( relevant legislation sections 381-390 TCA 1997 ) . It is also important to ensure that all other taxes such as VAT have been covered if relevant to the case.