Vintage champagne must come from a single year's harvest. There are no laws to determine the declaration of the vintage; it is up to the Champagne House to determine if the wine will best express their style. The better Houses will declare four or five times in a decade.
Vintage Champagnes generally have more complexity with rich, toasty characters to the wine, are great with food and can be aged for 10 to 15 years (though this does not help our turnover!).