When you will file ER-1 you need to enter challn deatil , so without making payment of excise duty you will not be able to fill that detail so you have to make payment before filling return .
09 April 2011
Without Payment of Excise Duty through Account Current, if payable, you can not fill complete details in the return, therefore, before submission of excise return, make payment.
10 April 2011
Please Not Excise duty epayment up to 6th of next month and march month payment 31st march. after that if you will pay Excise duty, interest and penality will impose upon you.