The BMI introduced new forms sometime after the end of October which are linked on their Brexit website specifically for the upgrade. These are linked on our Website – https://www.britishinaustria.net/the-guide/residence/a50brits/article-50-cards-forms-and-guidance/
These can be found in the “Daueraufenthaltsrecht nach dem Austrittsabkommen” section of the BMI German Brexit site and also under the ” Permanent right of residence according to the Withdrawal Agreement” section in English (see links below).
https://www.bmi.gv.at/312/brexit/start.aspx
https://www.bmi.gv.at/312/brexit/files/400_2025_Antragsformular-C_BREXIT_Daueraufenthaltsrecht_DE_V20251016_webBF.pdf
https://www.bmi.gv.at/312_en/brexit/start.aspx
https://www.bmi.gv.at/312_EN/Brexit/files/400_2025_Antragsformular-C_BREXIT_Daueraufenthaltsrecht_EN_V20251016_webBF.pdf
Could you please complete our Feedback form –
In addition, your father can contact the Consultate team – https://www.gov.uk/world/organisations/british-embassy-vienna#contact-us