Tower says it may have to increase the amount of cash it carries as part of conditions needed to get an operating license.
Under new Reserve Bank rules, all insurers will need a license to operate from 19 September.
Tower says it is in discussions with the central bank, as part of the licensing process, and it could result in it having to increase its minimum solvency margin.
Forsyth Barr analyst John Cairns says an increased margin is unlikely to have any big effect on Tower.
This is because Tower reported having a solvency ratio 175% higher than the regulatory requirement, at its half year results.