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HMRC internal manual

COTAX Manual

Background: typical case examples: company pays and self assesses on time

An established company meets its payment and filing obligations on time. The example shows the cycle of a compliant company, from AP end to the recording of the self assessment.

The events are numbered in date order, and identified as follows.

  • Business event - action taken or arising outside  HMRC.
  • Automatic event - automatic COTAX action.
  • Procedural action - action taken by an operator.
Order and type of event Action or actions taken
1 Business event Company AP ends (normal 12 month period).

Approximately 1 month after the recorded AP ends

2 Automatic event COTAX issues a notice to deliver, calculates the filing date (Word 42KB), records the specified period and the issue of the notice to deliver and creates the next AP on the COTAX record.

Some time later………………

3 Automatic event First payment reminder (PR1) issued, 12 days before normal due date (Word 49KB) as no payment or NIL payslip returned to Accounts Office.
4 Business event Payment received shortly before the normal due date.

Some time later………………

5 Automatic event CT205 return reminder issued 28 days before the filing date as the return is not yet logged.
6 Business event Return received by the filing date.
7 Automatic event COTAX automatically captures the details and records the self assessment.


  • COM33011 for a list of forms relevant to this subject
  • COM33012 for a list of functions to use in particular situations
  • COM33013 for legislation applying to this subject.