Serial numbers are 17 digits long following "S/N" and contain letters and numbers.
Locating the serial number
Example

See the product categories below to find your product and the serial number location.
Headphones
In-ear
(original packaging)

Over-ear
(inside ear cup)

Wireless Speakers
SoundLink® Color II and SoundLink® Mini II
(bottom)

SoundLink® Bluetooth Speaker III
(bottom)

SoundTouch® 10
(bottom)

SoundTouch® 20 and 30
(back)

SoundTouch® SA-5 Amplifier
(bottom)

SoundTouch® wireless link adapter
(bottom)

Home Cinema Systems
Lifestyle® home entertainment systems
(bottom of control console)

Soundbar systems
(back or bottom)

Acoustimass® 300 wireless bass module
(bottom)

Virtually Invisible® 300 wireless surround speakers
(bottom of receiver)

Acoustimass® home cinema speaker systems
(back)

Wave® systems
Wave® Music systems
(bottom)

Acoustic Wave® music systems
(back)

Docking speakers
- SoundDock® III speaker
Located on the bottom of the speaker
- SoundDock® XT speaker
Located on the bottom of the speaker
Stereo Speakers
- Companion® 5 computer speakers
Located on the rear of the bass module
- Companion® 20 computer speakers
Located on the bottom of the right speaker
- Computer MusicMonitor®
Located on the bottom of the right speaker
- Companion® 2 computer speakers
Located on the bottom of the right speaker
- Acoustimass® 5 stereo speaker system
Located on the rear of the bass module
- Acoustimass® 3 stereo speaker system
Located on the rear of the bass module
- 301® bookshelf speakers
Located on the rear of the speaker
- 201® bookshelf speakers
Located on the rear of the speaker
- 161® bookshelf speakers
Located on the rear of the speaker
- Free Space 51 outdoor speakers
Located on the bottom of the speaker
- 891® in-wall speakers
Located on the rear of the speaker
- 791® in-ceiling speakers II
Located on the rear of the speaker
- 691® in-wall speakers
Located on the rear of the speaker
- 591® in-wall speakers
Located on the rear of the speaker
- 191® in-wall speakers
Located on the rear of the speaker
- 251® outdoor speakers
Located on the rear of the speaker
- 151® outdoor speakers
Located on the rear of the speaker
- 131® marine speakers
Located on the rear of the speaker