Art. 20 Federal Act of October 13, 1965, on Withholding Tax (WTA)
Art. 20 LIA
If it becomes apparent that the payment of tax on income from movable capital would lead to unnecessary complications or evident hardships, the taxpayer may be authorized to fulfill their tax obligation by declaring the taxable benefit.
The Federal Council specifies the cases in which the declaration procedure is permitted. The declaration procedure must especially be allowed for dividends and appreciable monetary benefits paid within a Swiss or international group.
In the cases referred to in Art. 16, para. 2 bis, let. a and b, the declaration procedure is permitted even if the declaration of the taxable benefit, the request for authorization to use the declaration procedure, or the request for application of the declaration procedure is not submitted within the prescribed deadline.