Returns: view and amend return: time limit for amending the return
Just as HMRC has the right to repair an obvious error or mistake on the return the taxpayer has the right to amend it, within 12 months of the statutory filing date.
For amendment purposes the statutory filing date is 31 January following the end of the tax year, or 3 months from receipt of a Notice to File by the taxpayer (if it’s a late issue), whichever is the later.
The 31 January filing date applies for amendment purposes whether a return was filed on paper or online. So, a taxpayer who files a paper return on time for the year 2007-2008 onwards will have longer to file an amendment than someone who files online. The legislation is at TMA S9ZA.
The taxpayer amendment may be in the form of a letter, an amended return, an extra Supplementary Page or an amended Supplementary Page. HMRC will normally accept an amendment to a return or self assessment under Section 9ZA TMA whether notified by the taxpayer or trustee or by an agent authorised to act on the trust or taxpayer’s behalf, but it must be supplied in writing.
HMRC reserve the right to be satisfied in any particular case that the taxpayer has in fact authorised any amendment notified by an agent.
HMRC has 9 months from the date the taxpayer amendment is received in which to repair that amendment.