Leave travel allowance is fully taxable.
however leave travel concession or leave travel assistance for the person and his family is exempt u/s 10(5) of IT Act, 1961.Some of the relevant terms are:
1. Amount exempt under this section shall in no case exceed the amount of expenses actually incurred for the purpose of such travel subject to the following:
2. where the journey is performed on or after the 1st day of October, 1997, by air, an amount not exceeding the air economy fare of the national carrier by the shortest route to the place of destination;
Where such travel concession or assistance is not availed of by the individual during any such block of four calendar years, an amount in respect of the value of the travel concession or assistance, if any, first availed of by the individual during first calendar year of the immediately succeeding block of four calendar years shall be eligible for exemption.
3. where places of origin of journey and destination are connected by rail and the journey is performed on or after the 1st day of October, 1997, by any mode of transport other than by air, an amount not exceeding the air-conditioned first class rail fare by the shortest route to the place of destination; and
where the places of origin of journey and destination or part thereof are not connected by rail and the journey is performed on or after the 1st day of October, 1997, between such places, the amount eligible for exemption shall be :
(A) where a recognised public transport system exists, an amount not exceeding the 1st class or deluxe class fare, as the case may be, on such transport by the shortest route to the place of destination; and
(B) where no recognised public transport system exists, an amount equivalent to the air-conditioned first class rail fare, for the distance of the journey by the shortest route, as if the journey had been performed by rail.
The exemption shall be available to an individual in respect of two journeys performed in a block of four calendar years commencing from the calendar year 1986.