(a) Purpose. Section 7507 is intended to assist depositors of a bank which had ceased to do business by reason of insolvency to recover their deposits, by prohibiting collection of taxes of the bank which would diminish the assets necessary for payment of its depositors and also assist depositors of banks which are in financial difficulties but which, in certain conditions, continue in business.

(b) Requisites of application. In order that section 7507 shall operate in a case where the bank continues business it is necessary that the depositors shall agree to accept, in lieu of all or a part of their deposit claims as such, claims against segregated assets, or a lien upon subsequent earnings of the bank, or both. When such an agreement exists, no tax diminishing such assets or earnings, or both, otherwise available and necessary for payment of depositors, may be collected therefrom. If, under such an agreement, the depositors have the right also to look to the unsegregated assets of the bank for recovery, in whole or in part, the unsegregated assets are likewise, until they exceed the amount of the depositors' claims chargeable thereto, unavailable for tax collection. Any tax of such a bank, or part of any tax, which is once uncollectible under section 7507, cannot thereafter be collected except from any residue of segregated assets remaining after claims of depositors against such assets have been paid.

(c) Interest. For the purposes of section 7507, depositors' claims include bona fide interest, either on the deposits as such, or on the claims accepted in lieu of deposits as such.

(d) Limitations on immunity. Section 7507 is not primarily intended for the relief of banks as such. It does not prevent tax collection, from assets not necessary, or not available, for payment of depositors, from a bank within section 7507(a), at any time within the statute of limitations. In other words, the immunity of such a bank is not complete, but ceases whenever, within the statutory period for collection, it becomes possible to make collection without diminishing assets necessary for payment of depositors. In the case of a bank within section 7507(b), any immunity to which the bank is entitled is absolute except as to segregated assets. Any tax coming within such immunity may never be collected. With respect to segregated assets, such a bank is subject to the same rule as a bank within section 7507(a), that is to say, after claims of depositors against segregated assets have been paid, any surplus is subject, within the statute of limitations, to collection of any tax, due at any time, the collection of which was suspended by the section. The section is not for the relief of creditors other than depositors, although it may incidentally operate for their benefit. See §301.7507-4 and paragraph (b) of §301.7507-9.