The device certification process ensures compliance with cellular network standards. To use the Hologram network, your devices need a PTCRB or GCF certification, which will give you access to the networks available through Hologram without obtaining individual certifications for all end carriers. We do highly recommend getting certifications of any other carrier you expect to connect to, but those are not required.
We are unable to advise on certification needs for specific hardware builds. A lab like 7Layers, ( https://www.7layers.com/en/ ) provides comprehensive testing, certification, and consulting services. If you make any changes to the end device, it will have to be re-certified. To verify if a device is certified, we recommend reaching out to the end device manufacturer.
Please note: certain Hologram profiles require carrier specific certification. Reach out to support@hologram.io for additional information. If the device is not compliant with network standards, we reserve the right to suspend/pause SIMs.