Outward supply of service - domestic vs export

Sir,

I am in to software business which amounts to 50% of Domestic and 50% of export, but full ITC(inward supplies of services) is being availed and claimed fully against domestic outward supply of service, being export is zero rated with LUT.

Now my question is whether my existing procedure of availing and claiming of full ITC against supply of outward service( domestic) is correct, or do I have to proportionate ITC to the extent of Export and then go for refund while claiming the balance ITC against domestic supply of outward supplies. Kindly clarify.