Taxable person status: registration, turnover thresholds and role-based exclusions determine GST liability and exemptions. Defines the concept of a Taxable Person as persons carrying on business who are registered or required to be registered, excludes agriculturists, and exempts certain small suppliers until they exceed an aggregate turnover threshold, with a lower threshold for specified northeastern states; central, state and local governments are taxable only for commercial public authority activities, while employees, suppliers of non-taxable goods or services, and individuals receiving minimal-value personal services are not taxable persons.