EIM32951 - Other expenses: telephone charges: mobile phone example
A construction engineer often works out of the office on construction sites. She uses a mobile phone so that she can keep in touch with the office. The phone is mainly used for business calls.
The tariff for the mobile phone includes up to 10 minutes of free calls each month. In one month she pays £22, which is the rental charge only, because her total calls, all of which were business calls, amounted to 8 minutes. No deduction can be permitted because no expense has been incurred in making the business calls.
The following month she pays £28, which is £22 for rental and £6 for calls. Calls that are charged are paid for at a rate of 20p per minute. In the month she made calls totalling 40 minutes, of which 30 minutes were for business and 10 minutes were private. A deduction should be permitted for the cost of business calls, see EIM32945. The amount that can be deducted is £4.50, which is 75% of the call charges, because 75% of the total call time was made up of business calls.