Healthy lifestyles start here. Sign-up & save
2 year warranty
Expert tips and inspiration
Electric toothbrushes
All series
Philips Sonicare HealthyWhite+ Sonic electric toothbrush
Support
HX8921/99
Go to shop
Log in or create an account
You instantly have access to manuals, tailored support and more. Plus it’s quick and easy
Eco Passport
All (13)
How does the brushing guidance work in the Sonicare app?
Why is there a gap between my brush head and handle?
How long should my Sonicare toothbrush battery last?
Can I use my Sonicare charger with other toothbrushes?
How do I register my Sonicare toothbrush?
DiamondCleanStandard sonic toothbrush heads
AdaptiveCleanStandard sonic toothbrush heads
DiamondCleanCompact sonic toothbrush heads
I cannot connect my toothbrush to the Sonicare app
My brush head falls off my Sonicare toothbrush
My Sonicare toothbrush is not charging
My Sonicare toothbrush turns off by itself
My Sonicare toothbrush is vibrating less powerfully
Check the terms of your warranty and start a product exchange or repair
Start a product exchange
Apply for a warranty replacement product from Philips
Warranty
Our product warranty policies
Contacting Philips
We're happy to help you