Penalties for Inaccuracies: How to Process the Penalty: Suspension of a penalty: Notice to suspend a penalty: Treatment in a contract settlement
You must check the date from which these rules apply for the tax or duty you are dealing with. See CH81011 for full details.
For some taxes we can deal with a penalty for a careless inaccuracy in a contract settlement rather than formally assessing the penalty.
In such cases, even though you will not raise a formal assessment, you must calculate the penalty and tell the person about it before you can suspend the penalty.
For guidance on what to include in the amount of the offer, see EM6306.