SteuerGo FAQs

How is the percentage of business use for telecommunications costs calculated?

Do you use your private telephone for business or work-related calls? If so, the costs can be deducted as business expenses based on the work-related usage percentage.

There are two ways to determine the work-related usage percentage:

1. Flat-rate calculation

Without having to provide complicated proof of the business or work-related share of your telecommunications costs, you can claim a certain flat-rate amount of your monthly bill as business expenses: 20% of the monthly bill amount is deductible, up to a maximum of 20 Euro per month.

There are two methods for this flat-rate calculation:

• Either you apply the actual bill amounts for all months of the year. However, lower amounts than 20 Euro in some months cannot be offset against higher amounts in other months. The disadvantage is that you must submit all bills to the tax office.

• Or you calculate an average amount from the bill amounts for a representative period of three consecutive months and use this for the whole year. This method is recommended if your phone bills are significantly higher in a three-month period than in other months.

2. Individual proof

If your business-related telephone costs exceed the 20% flat rate, individual proof is advisable. For this, you must provide detailed proof of the work-related expenses for a representative period of three months and can then use this work-related percentage for the whole year. The tax office requires this proof anew each year.

• The three-month period must consist of consecutive months. You will certainly choose the months in which you make particularly many work-related calls. To prove the total costs, you must submit all bills for the year to the tax office.

• You determine the work-related percentage as follows: Add up the connection charges for work-related calls and internet usage during the three-month period on one hand, and the total connection charges for the three months on the other. Compare the two amounts. The result is the work-related percentage.

• Therefore, keep the itemised call records from your telephone company and mark the work-related calls. You should also note the name of the person you spoke to and the reason for the call to prove the work-related nature of the call to the tax office if necessary. The same applies to work-related internet costs.