Most treadmills, including folding treadmills must be disassembled in order to fit through the doorways in a home. They need to be disassembled prior to the move.
If you are moving I do not recommend that you allow the mover, professional or otherwise, to disassemble your treadmill. I have often seen treadmills damaged due to lack of knowledge and ability to do this task properly.
The most common issue is damage to the wiring harness and other connections that they often do not know are present and do not know how to disconnect, remove and then reinstall them.
A treadmill technician that has experience in not only servicing your treadmill but also has experience in treadmill assembly is most qualified for this task on both ends of your move.