Tax On Income Received On Late Father’s Estate

Good morning. I am in the process of finalising my late Father’s estate. My Accountant has advised me that any income received (eg. Building Society interest), from the date of passing until finalisation, is taxed at a flat rate of 20%. Does this include refunds from utilities: Telephone and Water Supply? I understand that this is reported to HMRC on a letter with an accompanying cheque for the tax due- is this correct? Thank you.

Hi Mark Taylor,
Refunds from utilities providers are not subject to tax.
Thank you. 
 

Thank you.