12 CFR §714.5

If the amount of the estimated residual value you rely upon to satisfy the full payout lease requirement of § 714.4(b) exceeds 25% of the original cost of the leased property, a financially capable party must guarantee the excess. The guarantor may be the manufacturer. The guarantor may also be an insurance company with an A.M. Best rating of at least a B + , or with at least the equivalent of an A.M. Best B + rating from another major rating company. You must obtain or have on file financial documentation demonstrating that the guarantor has the resources to meet the guarantee.