Every refurbished Samsung we sell is tested, graded and checked in-house at our Wolverhampton facility before it goes anywhere near dispatch. Nothing is outsourced to third-party overseas companies, so we can verify that every part of the process meets a high level of quality. Samsung phones need testing that goes beyond the basics, because the features people rely on most (AMOLED screens, cameras, charging ports, fingerprint sensors, foldable hinges) are exactly the kind of things that show wear first. That's why we use reputable testing software such as Phonecheck and CheckMEND to make sure that every phone is in full working condition and isn't blacklisted from UK networks.
Here's a stat most competitors won't share: only 15–20% of the phones we take in actually need any parts replacing. Most people assume "refurbished" means a phone's been pulled apart. Most of the time it hasn't. We test every component and only replace parts when genuinely necessary. All our refurbished Android devices, Samsung included, use original manufacturer parts, meaning that they work exactly the same as brand new phones.