Whenever you post a bundle, the mail center specialists relegate a number to that request, that number is called US Mail Service Tracking Number. It is otherwise called mark or article number. US Mail Service's following number is generally a 22-digit number. The number of digits might change relying upon the assistance you are utilizing. Various administrations have various kinds of following numbers. Does US Mail Service say no following data is accessible? If there is no status accessible or. .