Thanks for your reply, but I think the section you are quoting is for a debit card - I don't have any Thai bank cards.
I think this is the relevant section for the KPLUS app.
https://www.kasikornbank.com/en/kplus/instruction/adjust-money-kplus
I think that the smartphone app is the K-Plus platform . I'm not expecting any changes in the App (K-Plus)
Just had a quick look on the app and can't see any references to K-Biz
If your wife is a dependent with no income, you can claim 60k baht personal allowance for her. She doesn't need to be over 65 years old.
Will you be going back to the tax office tomorrow?