In order for a depository to be a Permitted Depository:
(a) The depository must (subject to Sec. 22.9) be one of the following types of entities:
(1) A bank located in the United States;
(2) A trust company located in the United States;
(3) A Collecting Futures Commission Merchant registered with the Commission (but only with respect to a Depositing Futures Commission Merchant providing Cleared Swaps Customer Collateral); or
(4) A derivatives clearing organization registered with the Commission; and
(b) The futures commission merchant or the derivatives clearing organization must hold a written acknowledgment letter from the depository as required by Sec. 22.5 of this part.