Before sending a device to us you should, where possible back up your data. We appreciate that with some devices that have been damaged that it may not be possible. We take great care to ensure there is no data loss but unfortunately as with any company including Apple we can not guarantee this.
In some rare specialist types of repair a restore is required but you will be notified if that is required.
SnappyApple is regulated by the ICO (Information Commisioners Office)