Tax deductions because of home-office?

What can I deduct from taxes due to home office? MyRight explains.

The answer in detail

What can I deduct from taxes through my home office?

Office

The basic rule is that the rental portion of a workroom can only be deducted from taxes if the employee has to do a substantial part of the work at home and the employer does not provide a workplace. In practice, 40% of a full-time workload, i.e. two full days, is considered a substantial part.
For such a deduction to be claimed, the workroom must be used essentially for the exercise of the profession. So if you work in the living room or bedroom, no deduction can be claimed. Since the conditions are strict, it is to be expected that a bed sofa in the study would not be allowed either, although there are other voices on this matter. 

Infrastructure costs

If the above-mentioned conditions of home office are met, infrastructure costs can also be deducted from taxes. However, this is only possible if they are not reimbursed by the employer. In many cantons these two cost items are already covered by the flat rate for other professional expenses. 
In the cantons LU, GL, AR, SG and VS, the actual costs can also be deducted, but these costs must then be proven.  

What has to be taken into account: 

Although many employees work from home due to corona conditions and can make the above-mentioned deductions. However, it should be noted that other deductins cannot be made: This applies in particular to flat-rate professional expenses (e.g. public transport and lunch). 

It should also be mentioned that the Zurich cantonal tax office has declared in a communication dated 9 September 2020 that these professional expenses can be deducted independently of the Corona crisis, but that no home office costs can be deducted for them. This is apparently also the practice in other cantons (e.g. Fribourg, Lucerne, Solothurn, Basel-Landschaft). 

How do I calculate the rent for the study?

There are various formulas for this: Rental value + service charges divided by number of rooms + 2
Net imputed rental value plus 10 percent service charges / number of rooms plus 1
Rental costs or rental value + additional costs/number of rooms + 2. Find out from your cantonal tax office which formula applies.