Is there any penalty for late fileing of IT return?

As per Section 139 of the Income Tax Act, Companies have to file returns by 30th september. This is irrespective of turnover/profit- even if turnover is nil, you got to file returns. Turnover is considered only for tax audit under Section 44AB.

If the returns are not filed by the due date, the interest will have to be paid u/s 234A at the rate of 1% per month or part of the month until filing of return or completion of assessment as the case may be, which is mandatory.

There is also a penalty of Rs. 5000 u/s 271F if the return is not filed by the end of the relevant assessment year (in this case, by 31-mar-2011)

But Interest under 234A, will be charged only when you have any profit for the year, if there is no profit then there is not base for calculating interest. But incase if you have any carry forward losses then you may loose the benefit of carryng it to next year.