IAAO Technical Standards
International Association of Assessing Officers (IAAO) maintains technical standards that reflect the official position of IAAO on various topics related to property tax administration, property tax policy, and valuation of property including mass appraisal and related disciplines. These standards are adopted by the IAAO Executive Board.
IAAO assessment standards represent a consensus in the assessing profession. The objective of the IAAO standards is to provide a systematic means by which assessing officers can improve and standardize the operation of their offices. The IAAO standards are advisory in nature and the use of, or compliance with, these standards is purely voluntary. If any portion of these standards is found to be in conflict with the Uniform Standards of Professional Appraisal Practice (USPAP) or state laws, USPAP and state laws shall govern.
IAAO technical standards are intended to guide property tax assessment officials, tax policy analysts, and administrators. Similar issues arise in any nation’s property tax systems. IAAO standards can provide guidance internationally. However, certain sections of these standards apply primarily to the United States and Canada, where the power to tax property is assigned to state, provincial, or territorial governments.
IAAO makes its technical standards publicly accessible on its Web site. Technical standards can also be purchased individually or as a full set using the IAAO online Marketplace.
IAAO allows reproduction of technical standards for personal use, educational purposes, property tax hearings, legislative development, as a supplement to local guidelines and standards, and for public information purposes. The content of IAAO technical standards are subject to change. Current official versions of technical standards are available only from IAAO. When citing a technical standard in other documents it is advisable to include the date the referenced standard was approved and a link to the current version on the IAAO website. IAAO also recommends reviewing references to IAAO technical standards annually to ensure that citations are still applicable.
Users of IAAO technical standards should request permission to use them for the stated purposes. Requests for permission to reproduce all or a portion of the technical standards can be sent to the Technical Standards staff liaison, Shannon Hiss at email@example.com. If a portion of a standard is used for the stated purposes, IAAO asks that the entire standard be cited in a bibliography or reference list. IAAO technical standards are intended to be read in the context of the entire document.
IAAO technical standards are protected by copyright. No part of IAAO technical standards may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher.
Research and Standards Committee
The Research and Standards Committee supports the mission and goals of IAAO by developing and maintaining technical standards of professional practice. The committee responds to inquiries about technical issues contained within technical standards. The committee's role is to ensure that IAAO maintains a leadership role by providing professional standards for the industry.
IAAO technical standards are protected by copyright.
IAAO reserves all rights inherent to copyright protection.
Guidance on International Mass Appraisal and Related Tax Policy
(approved January 2014)
The PDF document can best be viewed by downloading to your desktop and opening in Adobe Reader. The downloaded version has enhanced links that allow you to easily navigate the document.
This document provides guidance on mass appraisal of real property at market value. Recommendations made in this document should be considered for implementation as practical. However, not all recommendations apply in every instance and mass appraisal can be successfully implemented even if some recommendations are not implemented.
Do you have comments about this document? Send them to the Research and Standards Committee.