Interest: How to use this guidance
The guidance at CH140000+ covers some introductory topics relating to interest and then the more detailed rules for late payment interest and repayment interest.
This page explains how to use the guidance.
First, you must check whether the rules apply to the tax that you are dealing with. See CH140160.
Then you can look for the relevant rules. There is a general rule for both late payment interest and repayment interest. Then there are special provisions that amend the general rule in particular circumstances.
To find the interest rules for a particular situation, you need to start with the general rules, which are at
Then check whether there is a special provision for the particular situation that you are looking at. A special provision may modify an interest start date, for example. There is a list of the special provisions at CH149930. The detailed guidance about the special provisions is at
Note that whenever you calculate interest you must be careful to count the days correctly. See the examples at CH140220.
The guidance map also gives you an overview of the structure of this guidance.
There is a glossary at CH149950, which explains some of the key terms that we use in this guidance.