621. Amendment and correction of returns.

Not later than 12 months after the filing date1, a person may amend his personal return or trustee's return2 by notice in writing to an officer of Revenue and Customs3. A partnership return may be amended by the partner who made and delivered it, or his successor, by notice in writing to an officer of Revenue and Customs, given not more than 12 months after the filing date4. A company may amend its company tax return5 by notice in writing to an officer of Revenue and Customs not more than 12 months after the filing date6 or, in the