The United States said that although sanction relief will begin immediately the full benefits will not be released until the deal reaches its end.
– US State Department
The United States and the rest of our P5+1 partners will also take steps, in response to Iran fulfilling its commitments, to begin providing some limited and targeted relief.
The $4.2 billion in restricted Iranian assets that Iran will gain access to as part of the agreement will be released in regular installments throughout the six months.
The final installment will not be available to Iran until the very last day.