Flaky finance companies now won't be able to exploit the "opt-in" deposit insurance scheme being introduced in New Zealand following the release of additional details by Treasury and Reserve Bank of New Zealand yesterday.The chief shift is that finance companies that are rated below BB or areUnrated will now have to pay a monthly fee equal to 300 basis points on their insured liabilities. The fee, however, will only apply to growth in liabilities from last weekend.In practice only established finance companies (of which there are roughly 2000 including some very small funds) will be eligible.New finance companies will need to be rated BBB to join the scheme, and as finance companies are collapsing, not forming, in New Zealand there are unlikely to be too many of those unless established by a long-standing financial institution. The scheme will now also cover the subordinated debt of building societies and credit unions.Cash management trusts that invest wholly in New Zealand government debt or bank debt subject to a government guarantee and non-bank guaranteed debt (but only debt held on 12 October 2008) will also qualify for insurance.Finance companies that sign up will also have to restrict dividend payments and payments to related parties and allow regulators to review practices, including the appointment of an inspector.