Who is ISD?

Input Service Distributor under GST Model includes

• an office of the supplier of goods and / or services which
• receives tax invoices issued by supplier towards receipt of input services and/or goods and
• issues a prescribed document for the purposes of distributing the credit of CGST (SGST in State Acts) and / or IGST paid on the said services to a supplier of taxable goods and / or services having same PAN as that of the office referred to above

For more details: https://blogs.tallysolutions.com/gst-input-service-distributor/