Vietnamese Tax

If you're paying tax in Switzerland, no need to worry for VN tax since you're not working (or having any other source of income etc.) here in Vietnam.
Just keep your Swiss tax receipts with you .... that'll do.

You've just been here for 2 months. No need to rush.
In theory ....
The law says you need to stay in Vietnam for at least 183 days (6 months) to be considered a VN tax resident. (see Reference at the end)

Nobody knows what laws will be in force eight years later in 2025.
In Vietnam, laws keep changing all the time. 

Rest assured, for marriage registration, VEC and TRC no one will ask for your tax records.

I have a Japanese friend/neighbor who is living on his Japanese pension (transferred to his Viet acct), is married to a VN national and has recently purchased a property in Nha Trang.
I'll discuss your "pension issue" with him when we meet next week and will get back to you then. 


Reference:
Taxation in Vietnam – Personal Income Tax (“PIT”)
Vietnam - Income Tax (KPMG)
Vietnam Pocket Tax Book 2017 (PWC)

If it's retirement pension income....no tax. 

The links above from Senwl will also state that.

Thank's a lot Senwl and Yogi

These are good news.
I will check the links from Senwl and waiting on his news after he meet his neighbor

I don't pay tax in Switzerland. Because the double-tax agreement, I should normally only pay taxes abroad. But I am not unhappy if I don't must pay taxes in Vietnam  .