Service tax query

Practically, its a 3 year old case thats why your customer will not agree to accept such invoice as the excise assessment may have been completed or even if it is pending still they will not agree to accept the option of new bill as they had not taken any cenvat etc. and now not eligible to take cenvat credit.

However, he can not deny for the payment of service tax if at that time he had not issued any objection because he should have told you about these matter. Ultimately he had booked such bill with excise as expense and liable to pay money to your company.

One more thing you can do is to issue Excisable Supplementary invoice raising for Service tax amount only in current year. By doing this your customer can get the cenvat credit in current year.