Entering Phone information (line rental + business calls costs + personal calls costs)

We have directors who are using their own phone for business and personal calls. The company chooses to reimburse half of the line rental (landline or mobile), and the business calls.
According to HMRC, the line rental (or monthly tariff for mobile phone) and personal calls are taxable as personal benefits, business calls are not but need to be declared on P11D.
Are there different categories than “Telephone and Mobile Charges” that can/should be used for “landline” “monthly mobile tariff”, “business calls”, “personal calls”?