15 C.F.R. § 750.11
Under some circumstances, you may use a license issued for the export of items from the United States to export more than the value shown on that license. This additional amount is called a shipping tolerance. This section tells you, as the licensee, when you may take advantage of a shipping tolerance and the amount of shipping tolerance you are permitted to use.
(b) If you have not shipped the full quantity of items approved on the license, the value of all of your shipments under one license, up to the full quantity approved on the license, may exceed the total dollar value stated on that license by up to 10%, unless;
[78 FR 61902, Oct. 4, 2013]