Questions & Answers about Если код подтверждения не придёт, я перезвоню в банк.
This is a normal difference between English and Russian.
In Russian, when you talk about a real future condition, you usually use a future form:
- Если код подтверждения не придёт, я перезвоню в банк.
Russian does not avoid the future after если the way English does. So не придёт is exactly what you expect here.
If you used не приходит, that would sound like a general or repeated situation, something more like if the code doesn't usually come / isn't coming, not this one future case.
Because прийти is a perfective verb, and perfective verbs form the future with a single word:
- приду
- придёшь
- придёт
Perfective here shows one completed event: the code either arrives or it does not.
Будет приходить is an imperfective future and usually suggests an ongoing, repeated, or process-like action, which does not fit a one-time confirmation code very well.
So:
- придёт = will arrive once
- будет приходить = will be coming / will keep coming