Penalties for Failure to File on Time: In what circumstances is a penalty payable: Penalty date
The penalty date is the day on which a penalty for failing to file on time first becomes payable.
The first penalty is the initial fixed penalty, see CH62100, CH62340 and CH62720, and becomes payable on the penalty date, which is the day after the filing date. Therefore, the penalty date is always the day after the filing date.
Where a person becomes liable to further penalties because the return or other document remains outstanding for a certain period of time, for example at 6 or 12 months, a further penalty date is not created. Instead the further penalties are incurred at the end of a period from the penalty date.
Note: see CH62820 and CH62840 which explain the different rules for Real Time Information Returns.