A tax statement, by itself, is not sufficient to establish a value. It could, however, be used as a supporting document for an evaluation. All loans need to have the collateral evaluated. If you aren't doing an appraisal, you should have an evaluation in the file. Among other things, your policy should outline when each method is needed. We rewrote our policy earlier this year and it was a big overhaul! A lot more detail went in there. Good luck to you.