I’d think this is a pretty standard clause. My business recently got merchant facilities with BNZ and one of their requirements is the business banks with BNZ. While they didn’t say it was a requirement that I as the owner of the company also personally banks with BNZ, it was implied in a discussion that they preferred this.
Why is this I wonder? Obviously, banking is quite competitive and the banks want to maximise their per client revenue… But I think there is also a secondary reason which they probably won’t admit and that’s cross colateralisation (IE: Security / guarantors on one loan guanteeing all other obligations) and insight into the clients wider financial affairs for good or bad as part of upfront and ongoing “risk assessment”. In other words keep all your **** in order or else…
It’s also strongly indicated on the BNZ careers website they expect their staff to do their transaction banking with the BNZ and it’s indicated they want all their lending business as well.