There is no warranty on strings. Manufacturers recommend that you change the strings on your instrument as soon as you receive it. Your instrument has completed a long journey before it ever begins the final leg to your home. During this time the elements affect the strings and may shorten their lifespan. It occasionally happens that a string will fail during that final leg of the journey. Therefore, it is recommended that you purchase a replacement set of strings and consider changing your strings soon after it arrives. If you are a student you may want to change your strings every 3-4 months. If you are a rock star you may need to change your strings every week. If you store your instrument, you should consider changing the strings when you pick it up again.