Mistake in Assessment Year

u can contact the bank and/or write a letter to the bank informing that there was a mistake in mentioning the AY on Challan and mark a CC to NSDL.  The Bank will also follow up with NSDL and will get it rectified.

Yogesh is absolutely right

I think it does not matter now. amount of tax deposited by you will be shown to the credit of your account. you can take credit  of this in any a.yr. , if you take the cr. of this in 08-09 then it will be not be available for cr. in 09-10 in your account of if prob. you can write an application to your ITO mentioning your mistake and rectify it.

You can contact the bank manager and give a letter in writing stating the problem along with a photocopy of the challan paid.

Yes, you can intimate the bank about mistake in mentioning assessment year 2009-10 in place of 2008-09 in Challan No.281and show the copy of challan paid.

Is anyone got correct the mistake in assessment year ?