The Central Board of Indirect Taxes and Customs (CBIC) is working a scheme that will allow multi-state businesses to use a single PAN-based registration for goods and services Tax (GST) audit and investigations. The move aimed at improving ease of doing business may be introduced in the next six months, government sources told Moneycontrol. Multi-state businesses operating under a single Permanent Account Number (PAN) will be managed by a unified central GST authority.