National Class Action Act of 2003 - Amends the Federal judicial code to require: (1) the portion of any attorney's fee paid to class counsel based on a recovery of coupons in a class action settlement to be based on the value to class members of the coupons redeemed; and (2) the attorney's fee in such a settlement otherwise to be based upon the amount of time class counsel expended working on the action, subject to court approval.

Grants a U.S. district court jurisdiction over a class action in which one-third or fewer of the members of all proposed plaintiff classes in the aggregate are citizens of the State in which the action was originally filed. Lists grounds under which a U.S. district court may decline to exercise jurisdiction over a class action in which greater than one-third but less than two-thirds of the members of the plaintiff class are citizens of the State in which the action was originally filed. Bars a U.S. district court from exercising jurisdiction over a class action (with exceptions) in which: (1) two-thirds or more of the members of all proposed plaintiff classes are citizens of the State in which the action was originally filed; (2) the primary defendants are States, State officials, or other governmental entities against whom the district court may be foreclosed from ordering relief; or (3) the number of members of all proposed plaintiff classes in the aggregate is less than 100.

Allows a class action over which a district court would have jurisdiction under this Act to be removed to a U.S. district court by any: (1) defendant without the consent of all defendants; or (2) plaintiff class member who has intervened, seeks to be designated as a representative class member, and is not a named or representative class member without the consent of all members of such class.