Overview

Illinois employers liable for unemployment insurance must file quarterly wage and contribution reports with the Illinois Department of Employment Security (IDES).

The TaxBandits API supports the automation of Form UI-3/40, Illinois's quarterly UI contribution and wage report.

Forms supported

Form	Type	Filing frequency	Due date
Form UI-3/40	UI	Quarterly	Last day of the month following the quarter end

Key compliance notes

• Wage base. UI contributions apply to wages up to the annual per-employee wage base set by IDES.

• Zero filing required. Form UI-3/40 must be filed every quarter, even if no contributions are due.

Before filing, you can simulate the entire verification flow in our Sandbox environment without submitting real data to state agencies. See how

Available endpoints

Each endpoint below is specific to Illinois's withholding Form UI-3/40.

To use the following endpoints, you must first call the Auth method to obtain an access token. Include this token in your request header as a Bearer token. Refer to OAuth 2.0 Authentication for details on JWT-based authentication.

• Create — Generates a new Form UI-3/40 quarterly UI contribution and wage report for the specified quarter.

• Update — Modifies the details of a previously created Form UI-3/40 report before it's transmitted.

• Get — Retrieves the details of a previously created Form UI-3/40 report.