Taxability of severance payment

Though it is taxable, but relief can be taken u/s. 89 by spreading the lump sum payment to previous years by filing form 10E.

Thanks for the reply. But what if tax slab was same for last 3 years. And whether this form needs to be submitted before getting severance payment?

"But what if tax slab was same for last 3 years"

No use. Check for any loss of capital nature, otherwise consider it as current year salary, without filing form 10E.