Building & mounting of body on chassis provided by owner is a service, classified under heading 9988 taxed at 18% GST

Where applicant is engaged in business of building and mounting of body on chassis of different models of buses, if body is built on chassis provided by principal and fabrication charges, including certain material consumed during process of job work, have been charged, then activity amounts to supply of service under Heading No. 9988 and attracts 18 per cent GST and activity of mere mounting body on chassis supplied by owner amounts to supply of goods and merits classification under HSN 8707, attracting 28 per cent of GST