A6.401 Key self assessment return dates and the enquiry window
A self assessment enquiry is distinct from a compliance check. Self assessment enquires follow the rules in TMA 1970, ss 9A, 12AC for individuals and partnerships and FA 1998, Sch 18, para 24 for companies1.
Compliance checks consolidate these existing HMRC enquiry powers and give further powers under FA 2008, Sch 36. However in the case of a submitted tax return that has been filed under notice, or voluntarily, an enquiry generally needs to be opened if HMRC wish to request information from the taxpayer (see A6.405 for more on information notices being issued without a formal enquiry being opened)2. For more on the interaction between compliance checks and enquiries see CH206600 and A6.606.
The filing dates for the various returns that a taxpayer has an obligation to deliver under self assessment are discussed in detail in E1.202A. For corporate returns under self assessment see D1.1308. The enquiry window is linked to the filing date of a return (or its amendment), so the table below offers a summary of the key filing and amendment dates in relation to Income Tax Self Assessment (ITSA) returns (including trustee or partnership returns) and Corporation Tax Self Assessment (CTSA) returns3. The same limits apply when Capital Gains are included in the returns4.
For NRCGT returns see E1.235 and for