Spreadsheet Failure ModeManual Workflow
Root Operational Bottleneck
Remote-worker work and resident states are maintained in a jurisdiction spreadsheet, and reciprocal withholding is applied only if someone remembers the agreement.
Control Hazard & Audit Exposure
Interstate employees are withheld in both states, so refunds and amended returns become the control.
Deterministic Software ReplacementClient-Owned Architecture
Automated Interstate Tax Reciprocity Engine & Payroll Integration
Reciprocity engine that reads work and resident locations from HRIS and applies the treaty table to each pay run before withholding posts.
Continuous Assertion Rule
Reciprocity assertion: a pay line cannot withhold in both a work state and a resident state when a stored reciprocal agreement covers that pair on the check date.