179.This section sets out restrictions on when taxpayer notices may be given. A taxpayer notice cannot be given in relation to a transaction or an accounting period (to check the tax position for those) where a person has made a tax return in relation to that transaction or accounting period. However, a taxpayer notice could be given where a notice of enquiry had been given and the enquiry was not completed or where a designated officer suspected an issue with the assessed tax liability (including any reliefs) for the transaction or accounting period.