Change in customer's ECC No. (India taxation)


I need a help.

I’m using the Ax2009 version. My customer’s ECC No has changed. I have added the new ECC no in the Tax Registration Numbers, and also assigned the new ECC No. to the customer in Customer Card.

However, after updating the ECC No., the ECC No has changed even on the old posted transactions. I wish to have the new ECC No. only for the new transactions.

Can someone please help.