Illinois Form UI-50A is the Notice of Change employers file with the Illinois Department of Employment Security (IDES) when a business is sold, reorganized, closed, or needs an address, name, or phone update on its unemployment insurance account. You have 10 days from the date of the change to file it. The fastest route is the MyTax Illinois portal at mytax.illinois.gov; you can also mail or fax the paper form to IDES.
When You Have to File
The form covers four situations, and you only complete the parts that apply to yours:1Illinois Department of Employment Security. Illinois Form UI-50A – Notice of Change
- A change to your business name, mailing address, physical location, or phone number.
- Closure of your Illinois UI tax account because you’ve stopped all operations in the state.
- A sale, merger, reorganization, or change in legal structure, such as moving from a sole proprietorship to an LLC or corporation.
- A corporate merger or consolidation in which your corporation was absorbed by another entity.
The 10-day deadline is set by the Illinois Administrative Code, which requires written notice to IDES within 10 days of terminating business, transferring or selling substantially all business assets, or changing a trade name.2Legal Information Institute. Illinois Administrative Code tit. 56, 2760.110 – Employing Unit Terminating Business Missing it can hold up the transfer of experience rating to a new owner and can leave the outgoing owner exposed to the new owner’s tax obligations.
Keeping the address current is also your responsibility. If IDES sends notices to an address you never updated, those notices are still considered delivered.3Illinois General Assembly. 56 Illinois Administrative Code 2725.30 – An Employer’s Last Known Address
What to Have Ready Before You Start
Gather two identifiers before opening the form: your Illinois UI account number, which appears on past quarterly contribution and wage reports, and your Federal Employer Identification Number (FEIN) from the IRS. You’ll also need the effective date of the change, which IDES uses to determine when your tax obligations shift.
If you’re closing the account, file any outstanding quarterly reports and clear any contributions, interest, or penalties first. An open balance will delay the closure.
If you’re reporting a sale or reorganization, be specific about what changed hands. Selling the whole company looks different from selling a single branch or product line, and IDES uses the details to decide how to split the predecessor’s experience rating between the old and new accounts. You’ll also need information about the successor: legal name, any DBA, their IDES account number if they already have one, their FEIN if you know it, and their address. If the buyer hasn’t registered yet, write “not yet assigned” and IDES will follow up with them.
How to Submit the Form
Online filing through MyTax Illinois is the fastest option. It generates an immediate confirmation and often processes automatically, so your account updates sooner than it would by paper or fax.4Illinois Department of Employment Security. Employers: Forms and Publications The employer FAQ workflow on the IDES site routes you through the same portal steps.5Illinois Department of Employment Security. FAQs for Employers
If you’d rather send paper, mail the completed form to the address printed on it:
Illinois Department of Employment Security
115 South LaSalle Street, Floor LL2
Chicago, Illinois 60603-38171Illinois Department of Employment Security. Illinois Form UI-50A – Notice of Change
The fax number is 217-557-1948.1Illinois Department of Employment Security. Illinois Form UI-50A – Notice of Change Keep a copy of whatever you send and any confirmation you receive.
What Happens After You File
For a plain address, name, or phone change, IDES updates the account and you typically won’t hear back unless something’s wrong.
Sales and reorganizations trigger more work on the successor’s side. The new owner has to file Form UI-1 S&P, the Report to Determine Succession, so IDES can establish or update the successor’s tax account.6Illinois Department of Employment Security. Report to Determine Succession If the buyer has never registered with IDES at all, they also need to file Form UI-1, the Report to Determine Liability, within 30 days of starting operations.7Illinois Department of Employment Security. REG-UI-1 Report to Determine Liability Under the Unemployment Insurance Act Those succession questions can also be handled during online registration at MyTax Illinois.
IDES uses both the UI-50A and the UI-1 S&P to decide how the predecessor’s experience rating carries over. Its determination about whether the buyer acquired the “employing enterprise” of the previous owner directly affects the contribution rate the new owner will pay.
Successor Liability When a Business Is Sold
Illinois law tacks the seller’s employment history onto the buyer’s when the buyer continues operating the business. If the combined weeks of employment reach 20 or more in a calendar year, or combined taxable payroll hits $1,500 or more in a quarter, the buyer owes UI contributions on its own payroll for that year and at least the following one.8Illinois Department of Employment Security. Guide to the Illinois U.I. Act
There’s a more immediate risk, too. Under Section 2600 of the Illinois Unemployment Insurance Act, anyone buying a business or its assets should request a certificate from the Director of Employment Security confirming the seller owes no outstanding contributions, interest, or penalties. Without it, the buyer becomes personally liable for whatever the seller owed, up to the value of the property acquired, unless enough of the purchase price was withheld to cover the debt.8Illinois Department of Employment Security. Guide to the Illinois U.I. Act Requesting that certificate before closing is one of the simplest ways to avoid inheriting a tax problem.
A Warning on SUTA Dumping
Some employers try to lower their UI rate by setting up shell companies or buying small businesses with clean records. Federal law calls this SUTA dumping, and the SUTA Dumping Prevention Act of 2004 requires every state, Illinois included, to penalize employers who knowingly manipulate experience ratings through sham transfers.9U.S. Department of Labor. SUTA Dumping – Amendments to Federal Law Affecting the Federal-State Unemployment Compensation Program IDES reviews UI-50A and UI-1 S&P filings specifically to flag transactions that look like rate manipulation, and the consequences can include penalties plus a retroactive reassignment to the higher rate the employer was trying to avoid.