Rakesh,

>We forgot to take into consideration that we will have to give the Firm name in all the reports. Since, previously there was only one Firm, the Customer understood that the reports it of Firm A. Now he is not ready to pay for adding the Firm name in all the reports ( 20).
>
>The quotation just mentioned - Addition & selection of Firm.

Sounds like you gave a firm price quote for the multi-firm functionality, and I believe the customer is right to expect that the firm name will be on reports. You admitted that you forgot that, so I think you must correct the problem at no additional charge to the customer.

It should be quite easy to set up the reports with to reference a variable or App-level property for the firm name, and just change the programs to set that variable or property when the firm name is selected.