Dear Colleague,
There are 2 main criterions to be fulfilled :
(a) to every establishment which is a factory engaged in any industry specified in Schedule I and
in which [twenty] or more persons are employed, and ( FACTORIES)
(b) to any other establishment employing [twenty] or more persons or class of such
establishments which the Central Government may, by notification in the Official Gazette, specify in this behalf: ( FIRMS LIKE YOURS)
Hence you need to have a check on the preconditions and then move for coverage. As long as you are not meeting the criteria then stay away from coverage. However if you have employees who are already covered under PF and joined with you, you may need to go for voluntary coverage as you need to cover these employees into PF as per the requirements. You may consult your PF Enforcement Officer and then move on this for more clarity.