What to record
For each utility: who pays it (the tenant, you, or shared), the supplier, the account number and any notes, such as where the meter is. Who pays comes first because it changes what the rest means: whether a bill is a cost for you to log, and whether an empty month costs you money.
What your tenant sees
The supplier and who pays appear in the tenant portal and in the move-in email, so a new tenant knows who to call from the first day. The account number and your notes are private: they are never shown to the tenant or sent to them.
At every change of tenant
The record stays with the property, so the next tenancy starts with the same answers rather than a hunt through old bills.
Bills you pay yourself
Record them in Finance as expenses, so they count towards your tax figures.
