Yes, the facility for a gas consumer to provide their own meter is enshrined in the Gas Act.
However, this is more common for larger industrial customers, who have the engineering capability to manage the maintenance of such equipment.
Smaller gas consumers are permitted to own (or to arrange for provision of) their own gas meter, but must also ensure that it's properly maintained to ensure its safety and accuracy.
However, please note that in order to consume gas through the meter you will still need to have an appointed gas supplier and will be billed accordingly.