An Input service distributor (ISD) is a business which receives invoices for services used by its branches. It distributes the tax paid, to such branches on a proportional basis by issuing an ISD invoice.
The branches can have different GSTINs but must have the same PAN as that of ISD.
Let’s understand with an example.
Head office of ABC limited is located at Bangalore having branches at Chennai, Mumbai and Kolkata. The head office incurred annual software maintenance expense(service received) on behalf of all its branches and received the invoice for the same. Since software is used by all its branches, the input tax credit of entire services cannot be claimed at Bangalore. The same has to be distributed to all the three locations. Here, the Head office at Bangalore is the Input Service Distributor.