Series Title (Agency Series #): Description, Retention (Legal Citation)

Appeal Records (DART14-008): Records documenting property owner disagreement with the assessed value of a property and subsequent appeals. Includes appeals to the Board of Property Tax Appeals, Department of Revenue, tax court, magistrate court and small claims court. Records include opinions and orders, action/contact log, hearing notices, appeal petitions, correspondence, and supporting documentation.
Retention: Retain 6 years. (MOAR 166-150-0015(5))

Appraisal Records (DART14-001): Record of land and building appraisals including all elements used to determine the value of the property. Includes both residential/commercial property and industrial property appraisals. May include property identification number and legal description, owner name and address, diagram cards, appraisal activity log, current value, remarks, sales and building permit history, roll value history, sketch notes, appeal history, construction detail, improvements valuation, land valuation, and special use valuation. May also include records documenting valuation by year. Appraisal records are generally maintained in the assessment and taxation system with supporting electronic and paper documentation. 
Retention: Retain 12 years. (MOAR 166-150-0015(3))

Contamination Files (DART14-005): Documents history of properties whose valuation is affected by some sort of contamination and cleanup. Information is used to determine how much cleanup will cost and how long it should be offset against the property's value. Records include environmental reports, cost worksheet, property value reports, correspondence, and related records.
Retention: Retain 6 years after cleanup completed. (Unscheduled)

Personal Property Appraisal Worksheets (DART14-010): Used to check property and enter data into the appraisal system. Records include appraisal worksheets, comparison worksheets, property valuation records, and similar records. Information includes property account, location, and information about any changes necessary to the appraisal value. 
Retention: Retain until entered in system. (Unscheduled)

Personal Property Returns (DART14-002): Documents the value of all business machinery and equipment within the county to determine the valuation of personal property for taxing purposes. May include name of taxpayer/business, address, location, signatures, and purchase price and date purchased of business machinery. Currently includes a paper return and a variety of digital support documentation. 
Retention: Retain 6 years. (MOAR 166-150-0015(17))

Property Appraisal Cards (DART14-006): Record of land and building appraisals including all elements used to determine the value of a property. Property types include industrial, commercial, billboard, commercial income (confidential info maintained on a separate card from the commercial property card), and others. Cards show account number, property location and legal description, owners name and address, zoning information, ratio and levy codes, assessment and value history, maps and drawings of property, and related information.
Retention: Retain 12 years. (MOAR 166-150-0015(3))

Reference Maps (DART14-009): Maps documenting various topographic and political features for use in preparing tax collection maps. Includes railroad maps, state highway maps, other highway maps, General Land Office survey (1851), Metskers maps, Lewis and Dryden City of Portland map (1891), City of Portland boundary and annexation map (1922), City of Portland topographic maps (1991), unrecorded subdivision maps, and related maps.
Retention: Reain until superseded or obsolete. (MOAR 166-150-0015(7))

Residential, Commercial and Industrial Appraisal Worksheets (DART14-007): Used to field check properties, enter data into the appraisal system, and to verify data on appraisal cards. Records include appraisal worksheets, rent comparison worksheets, apartment valuation records, and similar records. Information includes property account, location, and information about any changes necessary to the appraisal value. Industrial worksheets are maintained by site number. Residential and commercial worksheets are maintained by tax lot number.
Retention: Retain 2 years after entered in system. (Unscheduled)

Sales Records (DART14-003): Documents information about sale of property. Information is entered into tax appraisal system and used to help determine property value. Records include face sheet, sales record, tax history, copies of property transfer records (deeds, mortgages, etc), and supporting documentation. Information includes classification, property location and legal description, account numbers, date of sale, recording information, terms, consideration, parties involved in sale, and related information.
Retention: Retain 12 years. (MOAR 166-150-0015(18))

Tax Exception Records (DART14-004): Used to enter information about property changes that affect valuation into the computer system and to notify property owners that they have twenty days to appeal the change in valuation and tax due. Changes include remodeling, significant additions, new property added or removed, clerical errors, and others. Includes correspondence, "20-day letters", worksheets showing change computations, and related records.
Retention: Retain 3 years. (MOAR 166-150-0015(1))