Minimum 20mins. Mostly longer, wasn't counting.
They don't. Suggested it. It's "noted". They have an MPesa for withdrawing money at their offices, but it only worked the first week. You got to withdraw via cheque, which you have to wait 4 working days for, then take to the bank, and wait for another day or 2 depending on which bank(for NBK it's instant, since they bank with them).
So if you needed the money urgently, LOL. Pole sana.
