Illinois DOR 2026: State Tax Filing, Refund, Login & Phone
A practical Illinois Department of Revenue guide for taxpayers, businesses, employers, retailers and tax representatives who need MyTax Illinois login help, IL-1040 filing, refund status, sales tax rates, business registration, withholding tax, corporate tax, notices, payments, regional offices and official IDOR contact paths.
Quick Answer: What Does the Illinois Department of Revenue Do?
The Illinois Department of Revenue, often called IDOR or Illinois DOR, administers Illinois tax programs, MyTax Illinois online services, IL-1040 individual income tax, business income tax, sales and use taxes, withholding tax, business registration, tax rates, notices, penalties, tax forms, regional office assistance and related taxpayer services.
For individuals
Use IDOR for IL-1040 filing, refund status, Illinois tax payments, IL-PIN, 1099-G lookup, estimated payments, extension payments, letters and notices.
For businesses
Use MyTax Illinois for registration, sales and use tax, withholding tax, business income tax, account updates, payments and closing a business account.
For retailers
Use IDOR tax-rate resources for general merchandise, grocery changes, local rates, destination-based rules, exemptions and sales tax filing.
Illinois DOR Key Facts for 2026
Use this table to understand the most important Illinois DOR items before you file, pay, register, check refund status or call.
| User question | Illinois DOR answer | Best next step |
|---|---|---|
| Where do I file/pay Illinois taxes online? | Use MyTax Illinois, IDORâs online account-management system for filing, paying, registering and managing tax accounts. | Open MyTax Illinois and choose the correct individual or business action. |
| When is the 2025 Illinois IL-1040 due? | For calendar-year filers, the original due date to file and pay 2025 Illinois individual income tax is April 15, 2026. | File electronically when possible and pay any tax due by April 15. |
| What is the Illinois individual income tax rate? | The Illinois individual income tax rate is 4.95% of net income. | Use current IDOR forms and instructions for final calculations. |
| What is the 2025 Illinois personal exemption amount? | The 2025 IL-1040 instructions list a personal exemption amount of $2,850. | Confirm with the current-year IL-1040 instructions before filing. |
| How do I check an Illinois refund? | Use IDORâs Whereâs My Refund / Income Tax Refund Status Inquiry. It checks current-year refund status. | Prepare Social Security number and exact expected refund amount. |
| What is Illinoisâ general sales tax rate? | Illinoisâ general state retailersâ occupation and use tax rate is 6.25% on general merchandise; local taxes may apply. | Use the IDOR tax rate database for the exact location and date. |
| What changed for Illinois grocery tax in 2026? | Effective January 1, 2026, Illinois eliminated the state 1% sales and use tax on grocery sales, but local grocery taxes may apply where adopted. | Retailers should verify local grocery tax and update systems. |
| What is the main IDOR phone number? | Taxpayer assistance is available at 1-800-732-8866 or 217-782-3336, MondayâFriday, 8:00 a.m.â5:00 p.m., except holidays. | Have your notice, SSN/FEIN, tax year, account type and payment records ready. |
Illinois Local Tips: Before You Use the Wrong Agency
Illinois tax searches can be confusing because IDOR, MyTax Illinois, the Secretary of State, the Illinois Comptroller, county treasurers, county assessors and IDES handle different problems. Use these shortcuts before you waste time on the wrong page.
Secretary of State is not IDOR
If you need to form an LLC, search a corporation, file an annual report or manage a registered agent, start with the Illinois Secretary of State. If you need a sales tax account, withholding account, MyTax payment or state tax return, start with IDOR.
Property tax is local-first
Illinois property tax bills, due dates and payment questions are usually handled by county treasurers or collectors. Assessment, valuation and exemption questions usually start with county assessment officials.
Chicago and Cook County tip
Chicago-area taxpayers should check combined local sales tax, home rule taxes, Cook County property tax offices and local business rules. IDOR may administer state tax, but many Chicago/Cook County issues are local.
Retailer tip for 2026
Retailers must pay close attention to 2026 grocery tax and local rate changes. The state grocery tax was eliminated, but some municipalities and counties may impose a local grocery tax collected by IDOR.
Illinois DOR Action Helper: Which Official Page Do You Need?
Choose your situation and this helper points you to the correct Illinois DOR, MyTax Illinois or related official path. It does not collect personal data.
Select what you need. The helper will give you the official page, what to prepare and the common mistake to avoid.
MyTax Illinois Login: File, Pay, Register and Manage IDOR Accounts
MyTax Illinois is IDORâs online account management program. Individuals and businesses use it for filing, payments, registration, refunds, account updates, business tax actions and many IDOR account services.
Use MyTax Illinois when you need to
- File or pay Illinois tax online.
- Register a new business using REG-1.
- Manage business tax accounts.
- Make individual income tax payments.
- Look up estimated payments, extension payments or credits.
- Update account or business information.
Before login, prepare
- SSN/ITIN for individual access or FEIN for business access.
- Illinois Account ID if you already have one.
- Tax type, tax year and filing period.
- Notice letter ID if responding to IDOR.
- Prior return and payment records.
- Email and authentication access for account recovery.
Illinois Individual Income Tax 2026: IL-1040, Due Date, Rate, Extension and IL-PIN
For calendar-year filers, 2025 Illinois Form IL-1040 is due April 15, 2026. Illinois grants an automatic six-month extension of time to file, but the extension does not extend the time to pay. If you owe tax, pay by the original due date to reduce penalty and interest.
| Individual tax item | What to know | User action |
|---|---|---|
| Form IL-1040 | Illinois Individual Income Tax Return for residents, part-year residents and nonresidents with Illinois filing requirements. | Use current IDOR forms and approved e-file options. |
| 2025 due date | Original filing and payment due date for calendar-year filers is April 15, 2026. | File and pay by April 15 when possible. |
| Tax rate | Illinois individual income tax rate is 4.95% of net income. | Use the current IL-1040 instructions for calculations. |
| Personal exemption | Tax year 2025 IL-1040 instructions list a personal exemption amount of $2,850. | Confirm eligibility and updated amounts before filing. |
| Automatic extension | Illinois grants an automatic six-month extension of time to file, generally to October 15, 2026 for 2025 calendar-year returns. | Pay any tax due by April 15 using Form IL-505-I or online payment options. |
| IL-PIN | Some taxpayers may need an Illinois PIN for electronic filing. | Use IDORâs IL-PIN tools or tax software instructions. |
Illinois DOR Refund Status: Whereâs My Refund, Current Year Limits and Replacement Checks
Use IDORâs Whereâs My Refund or automated Income Tax Refund Status Inquiry to check current-year Illinois individual income tax refund status. The tool requires your Social Security number and exact expected refund amount.
Before checking refund status
- Have your Social Security number ready.
- Use the exact expected refund amount from your return.
- Remember the online refund tool checks current-year refund status.
- For prior-year or amended refund status, call IDOR at 800-732-8866.
- If a refund check was mailed but lost or older than one year, contact the Illinois Comptroller.
Refund check replacement
If the refund status page says your check was mailed and it has been more than 30 days, or if you found an uncashed refund check older than one year, IDOR directs taxpayers to call the Illinois Comptrollerâs Office at 1-800-877-8078 for replacement check issues.
Illinois Business Tax Registration: REG-1, MyTax, Sales Tax and Withholding
Businesses can register electronically using MyTax Illinois or complete Form REG-1, Illinois Business Registration Application. IDOR says MyTax registration processing is usually about one to two business days, while paper REG-1 processing can take four to six weeks.
Businesses should check registration when they
- Sell taxable goods in Illinois.
- Need to collect retailersâ occupation or use tax.
- Have Illinois employees or payees requiring withholding.
- Need a business income tax or replacement tax account.
- Need to update, close or manage an Illinois tax account.
- Have liquor, tobacco, motor fuel or other special tax obligations.
Prepare before applying
- FEIN, SSN or owner identification.
- Legal business name and trade name.
- Business location and mailing address.
- Date Illinois activity begins.
- Tax types needed: sales, withholding, income, excise or other.
- Secretary of State entity information if applicable.
Illinois Business Workflow: Secretary of State â IRS â IDOR â Local License
Starting an Illinois business often requires more than one government step. IDOR registration does not form your LLC, and a Secretary of State filing does not automatically create every tax account.
| Step | Where to go | Why it matters | Common mistake |
|---|---|---|---|
| 1. Entity formation/search | Illinois Secretary of State | Forms LLCs/corporations and manages entity records. | Thinking IDOR forms your entity. |
| 2. Federal EIN | IRS | Needed for payroll, banking and many tax accounts. | Paying unnecessary third-party EIN fees. |
| 3. State tax registration | IDOR / MyTax Illinois / REG-1 | Creates tax accounts for sales tax, withholding and other state taxes. | Selling taxable goods before registering. |
| 4. Local license | City, county or local office | Some local governments require business licenses, local taxes or permits. | Assuming state registration replaces local requirements. |
| 5. Industry rules | Relevant state/local agency | Liquor, tobacco, food, cannabis, transportation and regulated businesses may need extra approvals. | Only registering with IDOR and ignoring industry licensing. |
Illinois Sales and Use Tax: State Rate, Local Rates, Grocery Changes and Retailer Filing
Illinoisâ general state retailersâ occupation and use tax rate is 6.25% on general merchandise. Local taxes can apply, so retailers and remote sellers should use IDORâs tax rate database and sales tax guidance for the correct location and period.
| Sales tax topic | What to know | Best action |
|---|---|---|
| General merchandise | State rate is 6.25% on general merchandise, including items required to be titled or registered by Illinois agencies. | Check local rates before charging customers. |
| Drugs and medical appliances | IDOR lists a 1% state rate on drugs and medical appliances. | Confirm product category and local taxes. |
| Groceries in 2026 | The state 1% sales and use tax on grocery sales was eliminated January 1, 2026, but local grocery taxes may apply where adopted. | Retailers must verify local grocery tax and update POS systems. |
| Local rate changes | Business district, county public safety, home rule, non-home rule, RTA and MED taxes can change combined rates. | Use IDOR rate bulletins and the tax rate database. |
| Remote sellers | Illinois sourcing and destination-based rules can affect whether ROT or Use Tax applies. | Review IDOR remote seller and marketplace facilitator guidance. |
| Filing | Retailers generally use MyTax Illinois to file and pay sales and use tax. | Keep sales records, exemption certificates, rate records and payment confirmations. |
Illinois Withholding Tax: Employer Registration, IL-941 and 2026 Withholding Tables
Employers and payers who are required to withhold Illinois Income Tax must register with IDOR and report when Illinois payroll begins. Illinois withholding uses the 4.95% income tax rate, and 2026 withholding guidance lists an exemption allowance of $2,925.
Employer withholding checklist
- Register electronically using MyTax Illinois, by REG-1 or at a regional office.
- Tell IDOR when Illinois payroll will begin.
- Use current IL-700-T withholding tables.
- File Form IL-941 when required.
- Keep payroll, W-2/1099, payment and filing records.
Unemployment is a different agency
Illinois withholding tax is handled by IDOR. Unemployment insurance questions usually involve the Illinois Department of Employment Security (IDES), although some business registration workflows may also connect with IDES.
Illinois Corporate and Business Income Tax: Corporate Rate, Replacement Tax and Pass-Through Rules
Illinois business tax can include income tax and Personal Property Replacement Tax. Corporations other than S corporations pay Illinois income tax at 7% and replacement tax at 2.5%. S corporations and partnerships generally pay replacement tax of 1.5% and do not pay Illinois Income Tax at the entity level, with income generally passing through to owners.
Businesses that should review this area
- C corporations doing business in Illinois.
- Corporations with Illinois-source income.
- S corporations and partnerships with replacement tax requirements.
- Trusts and estates with Illinois filing obligations.
- Businesses with federal changes or amended returns.
Common mistake
Do not confuse entity filing with tax filing. Illinois Secretary of State annual reports, federal IRS returns, IDOR business income tax, replacement tax, sales tax and withholding tax are separate workflows.
Illinois Property Tax: Why IDOR Is Usually Not Where You Pay Your Bill
Illinois property tax is local-first. IDOR provides property tax resources, equalization information and local government support, but property tax bills, payments, assessments and exemptions usually involve county or local officials.
| Property tax issue | Usually correct office | Why |
|---|---|---|
| Property tax bill or payment | County treasurer / collector | Billing and collection are local. |
| Assessed value | County assessor / supervisor of assessments | Assessment and valuation are local. |
| Exemptions | Local assessment office | Homestead and special exemptions are reviewed locally. |
| Appeal | Local board of review / appeal path | Deadlines and documents depend on local notices. |
| Statewide guidance | IDOR property tax resources | IDOR publishes guidance and equalization information. |
Illinois DOR Letter, Notice, Penalty or Collection: What To Do Next
An IDOR letter can involve refund verification, account status, missing returns, penalties, estimated tax, late payment, audit, collection or a business account mismatch. Do not ignore the letter, but verify it through official IDOR channels before paying or sharing sensitive data.
| Notice type | First thing to check | Best action |
|---|---|---|
| Refund or identity letter | Tax year, IDOR letter type and requested response method. | Use official IDOR links, not random email/text links. |
| Missing return notice | Tax period, tax type and confirmation records. | Compare with MyTax or filing confirmation. |
| Late-payment penalty | Due date, payment date and days late. | Review Publication 103 and payment records. |
| Estimated tax penalty | Quarterly estimated payments and safe-harbor rules. | Review IL-2210 or IL-2220 guidance. |
| Business tax notice | Illinois Account ID, tax type and filing period. | Prepare sales, withholding, payroll or income tax records. |
| Collection notice | Amount due, deadline and contact instructions. | Contact IDOR quickly using official numbers. |
Illinois Tax Records: IL-PIN, 1099-G, Estimated Payments, Copy of Return and Address Changes
Many Illinois DOR users are not filing a new return â they need a tax record, a payment lookup, a 1099-G, a copy of a return, an address update or help with a notice. Start with the Individuals page or MyTax Illinois when available.
Record tasks people search for
- Get an IL-PIN.
- Look up 1099-G information.
- Look up estimated payments, extension payments and credits carried forward.
- Obtain a copy of a tax return.
- Change address after filing.
- Review letters and notices.
Address-change warning
IDOR notes that most mail from the Department is not forwarded by USPS even if you have a forwarding address. If you move after filing, update your address with IDOR while verifying account information.
Illinois DOR Regional Offices: Chicago, Des Plaines, Fairview Heights and Local Help Strategy
IDOR regional offices can help with many taxpayer service issues, but not every tax, business or property issue belongs in a regional office. Call before visiting and confirm whether your issue requires an appointment, a county office, a MyTax action or mailed documentation.
Before visiting, bring
- Government photo ID.
- Notice letter and envelope.
- Tax return copy and payment proof.
- SSN/ITIN or FEIN and Illinois Account ID.
- Tax year, filing period and tax type.
- Power of attorney if representing someone else.
Call-before-visiting tip
IDOR regional office hours and services can vary. Some issues can be solved faster through MyTax Illinois, phone assistance or a county/local office. Property tax bill questions usually start locally, not at an IDOR regional office.
Illinois Department of Revenue Phone Numbers and Contact Paths
Use the correct IDOR phone number or official page based on your issue. Prepare account information before calling so the representative can verify your situation.
| Need | Official contact/path | What to prepare |
|---|---|---|
| General taxpayer assistance | 1-800-732-8866 or 217-782-3336 | SSN/FEIN, tax year, notice, account type and payment records. |
| TTY general inquiries | 1-800-544-5304 | Use for hearing-impaired TTY services. |
| TTY collections | 1-888-261-2718 | Use for collections-related TTY services. |
| Refund replacement check | Illinois Comptroller: 1-800-877-8078 | Use when an IDOR refund check was mailed, lost, older than one year or needs replacement. |
| Business registration forms | IDOR says registration forms are also available by calling 1-800-356-6302 | Use for REG-1 paper form support if needed. |
| Regional office | Use IDOR regional office locations page | Confirm office hours and bring records. |
Illinois DOR FAQs
Visible FAQs below match the FAQPage schema included at the end of this article.
What is the official Illinois Department of Revenue website?
The official Illinois Department of Revenue website is tax.illinois.gov. Use it for official tax forms, refund status, contact information, tax rates and taxpayer guidance.
What is MyTax Illinois?
MyTax Illinois is IDORâs online account-management system for filing, paying, registering and managing Illinois tax accounts.
What is the Illinois DOR phone number?
Illinois DOR taxpayer assistance is available at 1-800-732-8866 or 217-782-3336. Representatives are available Monday through Friday, 8:00 a.m. to 5:00 p.m., except observed holidays.
What is the Illinois individual income tax rate?
The Illinois individual income tax rate is 4.95% of net income.
When is the 2025 Illinois IL-1040 due?
For calendar-year filers, 2025 Illinois Form IL-1040 and any tax owed are due April 15, 2026.
Does Illinois offer an automatic filing extension?
Yes. Illinois grants an automatic six-month extension of time to file, but the extension does not extend the time to pay tax owed.
What is the 2025 Illinois personal exemption amount?
The 2025 Illinois IL-1040 instructions list the personal exemption amount as $2,850.
How do I check my Illinois refund status?
Use IDORâs Whereâs My Refund or Income Tax Refund Status Inquiry and prepare your Social Security number and exact expected refund amount.
Can I check a prior-year or amended Illinois refund online?
The IDOR refund status application is for current-year refund status. For prior-year or amended refund status, call IDOR at 800-732-8866.
Who do I call for a lost Illinois refund check?
For a lost, replacement or older Illinois refund check, IDOR directs taxpayers to call the Illinois Comptrollerâs Office at 1-800-877-8078.
What is Illinoisâ general sales tax rate?
Illinoisâ general state retailersâ occupation and use tax rate is 6.25% on general merchandise, with local taxes that may apply.
What changed with Illinois grocery tax in 2026?
Effective January 1, 2026, Illinois eliminated the state 1% sales and use tax on grocery sales, but municipalities and counties may impose local grocery taxes where adopted.
Where do I find Illinois sales tax rates by location?
Use IDORâs tax rate database, rate bulletins and sales tax rate pages to verify current, historical and upcoming rates by location.
How do I register a business with Illinois DOR?
You can register electronically using MyTax Illinois or file Form REG-1, Illinois Business Registration Application.
How long does Illinois business registration take?
IDOR says MyTax Illinois registration processing is approximately one to two business days, while paper REG-1 processing can take four to six weeks.
Is the Illinois Secretary of State the same as IDOR?
No. The Secretary of State handles business entity records and filings, while IDOR handles Illinois tax accounts, registration, filing, payment and tax notices.
Who must register for Illinois withholding tax?
Employers or payers required to withhold Illinois Income Tax for Illinois employees or payees must register with IDOR and report when Illinois payroll begins.
What is Illinois withholding tax rate guidance for 2026?
IDORâs 2026 withholding tables use the 4.95% Illinois income tax rate and list a 2026 exemption allowance of $2,925.
What is the Illinois corporate income tax rate?
Corporations other than S corporations pay Illinois income tax at 7% and replacement tax at 2.5%.
Do Illinois S corporations and partnerships pay Illinois Income Tax?
Generally, S corporations and partnerships do not pay Illinois Income Tax at the entity level, but they pay replacement tax of 1.5% and income generally passes through to owners.
What is the Illinois late-payment penalty?
IDOR penalty guidance says late-payment penalty can be 2% when payment is 1â30 days late and 10% when payment is 31 or more days late, with higher rates possible in audit-related situations.
Does an Illinois extension extend time to pay?
No. An Illinois extension extends time to file, but it does not extend the time to pay tax owed by the original due date.
Does IDOR handle property tax bill payments?
Usually no. Illinois property tax bills and payments are generally handled by county treasurers or collectors.
Who handles Illinois property assessments and exemptions?
Property assessments, valuations and many exemptions are usually handled by county assessment officials or local offices.
What should I prepare before calling Illinois DOR?
Prepare your SSN or FEIN, tax year, notice letter, account type, Illinois Account ID if available, filing period, payment records and a short explanation of the issue.
Can I visit an Illinois DOR regional office?
Yes, IDOR has regional office locations, but you should call or verify services before visiting and bring identification plus tax records.
How do I get a copy of an Illinois tax return?
For taxes included in MyTax Illinois, some filed returns can be viewed after login. If no online view is available, you may need to request a paper copy.
Should I update my address with IDOR after filing?
Yes. IDOR notes that most mail from the Department is not forwarded by USPS, so taxpayers should update their address if they move after filing.
What should I do if I receive an IDOR notice?
Read the notice type, tax year, deadline and requested action, compare it with your records, and respond through official IDOR instructions before the deadline.
Is this website the official Illinois DOR website?
No. This is an independent informational guide. Use the official IDOR website and MyTax Illinois for filing, payments, refund status, account access and official decisions.
Final Recommendation: Use This Page as Your Illinois DOR Roadmap
Start here to understand the correct Illinois DOR path, then complete sensitive actions only through official IDOR or MyTax Illinois pages. For individual taxes, remember the 2025 IL-1040 due date is April 15, 2026. For businesses, register and manage accounts in MyTax Illinois when possible. For property tax bills, start locally with county officials. For notices, refunds and penalties, keep confirmations and call IDOR only with complete account details.
Last editorial update: June 5, 2026. Verify final filing, payment, refund, tax rate, property tax and legal details on official Illinois Department of Revenue pages.