ATS Assessor Treasurer Software review
A free, county-focused system covering assessments, treasury workflows, records, and payments.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
ATS Assessor Treasurer Software is an open-source property-tax management application developed with Kitsap County, Washington. It is designed for county assessment and treasury teams managing real and personal property, assessments, levies, payments, fees, and related casework. The system also supports new construction, destroyed property, bankruptcies, foreclosures, LIDs, and a public-facing Personal Property Online module. Its focus is operational coverage for public-sector property-tax administration rather than general accounting or consumer tax preparation.
The published model is a significant fit for budget-conscious teams: ATS is freely available and open source. That can give counties more control over adapting the application, while Velosys offers implementation, customization, deployment, training, and consultation services. The product is therefore suited to organizations prepared to make decisions about configuration, deployment, and ongoing ownership. Teams should evaluate how those service needs align with their internal technical capacity and procurement approach.
ATS’s strongest case is its breadth within county property-tax workflows. It can manage assessments and levies, maintain property records, create payment and advance payment plans, control late fees and NSF payments, configure accounting interfaces, run flexible queries, and expose application data through a RESTful API. This range makes it a practical candidate for counties seeking an open-source foundation across assessment and treasury functions. However, the application is described as being in development, and Kitsap County is considering making it available to other counties. Counties seeking a mature, broadly available commercial system may prefer an alternative, while teams prioritizing cost control and adaptable public-sector software should consider ATS.
ATS Assessor Treasurer Software pros and cons
- Where it wins
- Free, open-source model for county assessment and treasury operations
- Covers property records, levies, payment plans, and special cases
- RESTful API, accounting interfaces, and public Personal Property Online module
- Where it doesn't
- The application is still described as being in development
- Designed for county operations rather than broad commercial use cases
- Platform coverage and integrations are not established
ATS Assessor Treasurer Software fact sheet, pricing and score →
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