Requirements, regulation on loan interest rates between two connected companies

Hello! Is there any regulation published by HMRC or another body according loan interest rates between two connected companies? If in agreement is information that interest on the loan amount will be charged until the date of repayment, should interest be accrued monthly in company accounts? Is there some like minimum loan interest rate? Thank you!

Hi Anna,
A link to our guidance on intercompany loans is attached below and can be found under ‘CFM35000’.
If when consulting the provided guidance it does not answer or cover your question.
Then you will need to seek financial advice from e.g an accountant. 
CFM35000 - Loan relationships: connected parties: contents
Thank you.