Do I need to be registered as a doctoral student by the submission deadline of my Doc.CH application?

No, except if you are not a Swiss national and have a foreign degree (master's or equivalent). The maximum period of employment funded by the SNSF is 4 years for doctoral students. A Doc.CH grant has a running time of 2 to 4 years. The actual start date of the dissertation is decisive for calculating the 4-year time window. If the actual start of the dissertation took place more than 2 years before the envisaged start of the grant, it is therefore not possible to request a Doc.CH grant. However, in response to a written request giving reasons, the eligibility period of 4 years starting from the actual start date of the dissertation may be extended. Accepted reasons for a delay are set out in Clause 1.11 of the general implementation regulations for the Funding Regulations.