I assume your current phone was purchased in New Zealand? I know Visible offers a limited amount of devices that are compatible with the service and I imagine they are given a list by manufacturers (Samsung, Google, apple, etc.) of the devices (IMEIs) that are sold in the United States. That is mostly the issue, however I am not 100% curtain..anyone want to clarify?
I have heard that phones that came up as not IMEI registered with visible were still able to get service and work normally.
International model numbers are distinctly different than US models; however, the problem I see is getting a SIM . When ordering, the first thing you go through is the compatibility check. Having ordered a SIM kit through Best Buy, there was no compatibility check. However it was the first thing checked on activation before proceeding. Even then and despite a compatible phone, activation failed and after 11 days still no resolution. I'd say look for other alternatives given the activation issues Visible is having and no real support