I have always followed the rule that interest received is taxed by the taxpayer's home state.  However this one is giving me a headache.  Taxpayer's inherited an installment sale of farm ground in a different state.  I have all of the information needed to file the 6252, no problem there.  However the buyer (who is out of state) issued them a 1099int for the interest portion and since that is a part of the installment sale income should it go on the non-resident state return with the principle portion or is it income to the home state.  Thanks for any advice, I need to get this finished off and out the door.