Sir, A manufacturer may bring duty paid goods in the registered manufacturing premises for trading purpose and no permission in this regard is warranted from the Central Excise Department. However, a factory cannot be allowed to receive goods from outside, which are identical to those manufactured by them for which proper permission from the Commissioner is required.
Further, you will be required to maintain Separate books of accounts and also carry out Remarking of area intending for trading activities.
Also, service tax credit shall be required to be reversed for common services used both for the manufacturing and trading activities, such as security supply services, etc.