Company aspects
In principle, a company agreement or the employment contract regulates whether and how you can use a company cell phone. Please ask your employer about the guidelines (compliance) in your company.
Technical aspects
From a purely technical perspective, Everphone equips its rental devices with MDM software or integrates MDM solutions already available in a given company. This ensures the separation of private and business data on company cell phones as required by the DSGVO, because the MDM creates a separate area on the device for company data only. This makes mixed use (private/business) possible without further ado.