Guys, this is actually a Central Bank requirement and ALL banks are supposed to be asking for it per CBK directives. So its not a CFC, Barclays, DTB or NIC peculiarity. Even if you bank isn't asking this sooner or later it will, as borne out by diff. wazuzu's experience above.It will catch up with Equity, too, if that's what they are doing.
It began as a CBK-KRA collabo to kamata tax cheats and who better to do that with KRA than CBK which regulates banks where the actual monies are held. And it made lots of sense for KRA to seek CBK's co-operation (since both work for the same govt). In time this extended to opening of a/cs as well.
Contrary to what many of u think, getting a PIN cert in areas from Nbi is a walk in the park. In Thika, for instance, you can have it in under 2 hrs.
On certification, so long as the original PIN cert has the KRA stamp and has some official's signature this should suffice.