Let's not dance around the question here, will you lose your data when you're getting your phone repaired?
Now, the question is quite short and to the point, but the answer is a little bit more complicated than that. In short, we don't remove any data from any device that's booked in for repair, so you don't need to back up a device before bringing it to us for repair.
On the other hand, this is only half of the answer, as there is always the possibility of losing data on a device day to day while using it. Your phone can suffer a software crash or power issue that could cause data to be erased, it could be water damaged, or obviously if you lose your phone or it's stolen data will be lost. In recent years, Apple's IOS and Google's Android OS have been pushing you to make use of online cloud storage for the data that's stored on your phone. These services, or backing up your phone using a computer or iTunes are highly recommended, as they will just give you more security if the worst should happen. whichever way you do it, we cannot overstate how important it could be the have a back up of your device stored somewhere else.
Over the years that we've been in business, we've seen hundreds (if not thousands) of situations where someone has lost data on their device, and there's only one common theme with all of them; the customer never thought it would happen to them. If you've dropped your phone and broken the screen, you're fairly safe in most cases, and if you have done worse to the phone and it's not powering on, most of the time the data can be recovered. However, there are some cases where the date is completely gone and can't be retrieved, and based on how much we use our phones for these days, that's the last thing that we want to happen.
If the worst has happened, we do perform data recovery on all manner of devices, but at the same time, it never hurts to have that safety net.