On the first page of the History of Your Watch booklet, the A. Lange & Söhne Guarantee Seal is displayed. It documents the individual data of your A. Lange & Söhne watch such as the reference, movement and case serial numbers. Please note that all guarantee documents will be issued only once.

Our watchmakers perpetuate Ferdinand A. Lange’s ambition to craft “the world’s finest watches”. Part of this ambition is the International Lange Guarantee. It is valid for two years after the date of purchase recorded in the History of Your Watch booklet. It applies to newly purchased watches and service interventions performed.