How Boston's Property Records Ended Up Riddled With Duplicate Images — and What the City Is Doing About It

Boston's Assessing Department has quietly been working through a backlog of roughly 14,000 property records flagged for duplicate or mismatched images since late last year, a problem that traces back more than a decade to the city's first serious push to move paper files online. The issue matters now because those records feed directly into mortgage applications, title searches, and the city's own tax-assessment appeals process — and errors compound every time a document gets pulled and re-filed.

The stakes are not abstract. When a Jamaica Plain triple-decker goes to closing on Lamartine Street and the title company pulls the assessing photo only to find a Mattapan two-family staring back, the deal can stall. Real estate attorneys working along Centre Street say the mismatch problem has become routine enough that they now treat a manual photo check as standard due diligence on any Boston transaction.

A Paper Trail That Started Coming Apart in 2014

The root of the problem is the 2014 contract the city signed with a now-defunct vendor to digitize roughly 170,000 property-inspection photographs stored on physical slides and prints in the basement of City Hall on Cambridge Street. The vendor delivered scanned images on a rolling basis over five years, but the metadata linking each image to a parcel ID was generated through an optical-character-recognition process that had an acknowledged error rate of about 4.2 percent, according to internal city documents obtained under a public records request. On a corpus of 170,000 files, that math produces roughly 7,100 potential mismatches from that round of scanning alone.

A second wave of errors arrived after the city migrated its assessing platform to a new software system in August 2023. The migration, handled by a contractor brought in under the Wu administration's broader digital-services overhaul, used an automated script to map old parcel IDs to new ones. Assessor's office staff identified the script's logic errors within weeks, but by then thousands of records had already been written to the production database. The city froze new public uploads for 11 days in September 2023 while technicians worked through the most acute mismatches.

The Dorchester Reporter first flagged the scale of the problem in a November 2024 piece focused on a cluster of errors concentrated in Codman Square, where a block of Franklin Field-area condominiums had their inspection photos swapped with images from East Boston's Maverick Street. That story prompted the Assessing Department to commission a full audit, completed in March 2025, which put the total number of affected records at 14,200 — about 8.3 percent of the city's roughly 171,000 taxable parcels.

The Fix, and Why It Takes This Long

The city is now roughly 60 percent through remediation, according to figures the Assessing Department shared with the Boston City Council's Government Operations Committee at a June 17, 2026 hearing. Staff are correcting records manually rather than running another automated script, a decision driven precisely by how badly the 2023 automation went. At the current pace of about 800 corrected records per week, the department expects to clear the remaining 5,600 flagged files by the end of October 2026.

The broader lesson is not lost on the Wu administration's Office of New Urban Mechanics, which has been piloting a new image-validation protocol using hash-matching — essentially a digital fingerprint check — on all incoming property photographs since January 2026. The protocol is already standard practice in several large municipal assessing offices, including Philadelphia's Department of Revenue, which deployed a similar system in 2021 after its own post-migration audit revealed a 6 percent mismatch rate.

For homeowners in Roxbury, South Boston, or anywhere else in the city who want to verify their own parcel's image is correct, the Assessing Department's online portal at boston.gov/assessing allows any property search by address. If the photo doesn't match the building, the department asks residents to file a correction request through the city's 311 system — case type listed as "Assessing Department — Property Record Error." The department says it has resolved 311-submitted image corrections within an average of 19 business days this calendar year.