Version: 2.0.0

Create

Use this endpoint to create Form IL 3/40 (Illinois Quarterly Tax and Wage Report) for an employer (payer), reporting quarterly wages, taxable wages, and unemployment insurance (UI) contributions due, along with required employee wage details for the corresponding quarter.

Form IL 3/40 must be filed every quarter, even if no wages were paid.

Updated wage base limits for Illinois Form UI-3/40:

Tax year	Wage Base Limit per employee
2025	$13,916
2026	$14,250

POST StateFilings/ILUI/Create

Run in Postman

Request Body

Field	Type	Description
StateUIRecords	Object[]	Object to identify the records.
SequenceId	String	A unique identifier for this record. Size Range: ..50
ReturnHeader	Object	Contains business information.
TaxYear	String	The tax year for which the Form IL340 is to be filed. Allowed values 2025,2026
Qtr	String	The quarter for which the Form IL340 is to be filed. Allowed values "Q1", "Q2", "Q3", "Q4"
Business	object	Object to identify the Business Details.
BusinessId	Guid	Optional Use the unique Business ID (Generated by TaxBandits) that you received in the response of the Business CREATE Endpoint. If you do not have a Business ID, ignore the field. By giving the Business ID, you do not have to provide all the business information again.
PayerRef	string	Optional Your unique identifier for the payer. Can replace BusinessId in future requests. Size Range: 50
IsDefaultBusiness	Boolean	When set to TRUE, this business will be set as the default across requests that do not specify a business.
TINDetails	object	TIN information for the business.
Format	string	Specifies how the TIN is passed. Allowed values "PLAIN_TIN" — Pass TIN directly. "TOKENIZED_TIN" — Pass tokenized TIN.
TINType	string	Specify the TIN type of the business. Allowed values "EIN", "SSN", "QI-EIN", "ITIN", "WP-EIN", "WT-EIN", "NQI-EIN", "IRSN"
TIN	string	The TIN value according to the Format selected.
IndividualNm	object	Required when TINType is SSN. Provide individual name fields instead of BusinessNm.
FirstNm	string	The first name of the individual. Size Range: 20
MiddleNm	string	Optional Middle name of the individual. Size Range: 20
LastNm	string	The last name of the individual. Size Range: 20
Suffix	string	Optional Suffix of the individual's name. Allowed values "Jr", "Sr", "I", "II", "III", "IV", "V", "VI", "VII"
BusinessNm	string	Legal name of the business. Required when TINType is EIN. Size Range: 75
NameCtrl	string	Name control of the business as registered with the IRS. Size Range: 3..4
DBADetails	object[]	Optional DBA (Doing Business As) information.
DBANm	string	Name of the DBA. Size Range: 75
DBARef	string	Unique identifier for the DBA. Size Range: 1-50
DBAId	Guid	TaxBandits-generated DBA identifier.
Address	object[]	Address information of the DBA.
Address1	string	Street address or PO Box. Size Range: 46
Address2	string	Optional Suite or apartment number. Size Range: 46
City	string	DBA's city. Size Range: 50
ProvinceOrState	string	DBA's province or state name. When the country code is US: Allowed values "AL", "AK", "AZ", "AR", "CA", "CO", "CT", "DE", "DC", "FL", "GA", "HI", "ID", "IL", "IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA", "MI", "MN", "MS", "MO", "MT", "NE", "NV", "NH", "NJ", "NM", "NY", "NC", "ND", "OH", "OK", "OR", "PA", "RI", "SC", "SD", "TN", "TX", "UT", "VT", "VA", "WA", "WV", "WI", "WY", "AS", "FM", "GU", "MH", "MP", "PW", "PR", "VI", "AA", "AE", "AP" When the country code is CA: Allowed values "AB", "BC", "MB", "NB", "NL", "NT", "NS", "NU", "ON", "PE", "QC", "SK", "YT" Note: The size range is set to 50 for all countries except the United States and Canada.
Zipcd	string	DBA's ZIP code. Size Range: 5-16
Country	string	DBA's 2-character country code. Allowed values "US","AF", "AX", "AL", "AG", "AQ", "AN", "AO", "AV", "AY", "AC", "AR", "AM", "AA", "AT", "AS", "AU", "AJ", "BF", "BA", "FQ", "BG", "BB", "BO", "BE", "BH", "BN", "BD", "BT", "BL", "BK", "BC", "BV", "BR", "IO", "VI", "BX", "BU", "UV", "BM", "BY", "CB", "CM", "CA", "CV", "CJ", "CT", "CD", "CI", "CH", "KT", "IP", "CK", "CO", "CN", "CF", "CG", "CW", "CR", "CS", "IV", "HR", "CU", "UC", "CY", "EZ", "DA", "DX", "DJ", "DO", "DR", "TT", "EC", "EG", "ES", "EK", "ER", "EN", "ET", "FK", "FO", "FM", "FJ", "FI", "FR", "FP", "FS", "GB", "GA", "GG", "GM", "GH", "GI", "GR", "GL", "GJ", "GQ", "GT", "GK", "GV", "PU", "GY", "HA", "HM", "VT", "HO", "HK", "HQ", "HU", "IC", "IN", "ID", "IR", "IZ", "EI", "IS", "IT", "JM", "JN", "JA", "DQ", "JE", "JQ", "JO", "KZ", "KE", "KQ", "KR", "KN", "KS", "KV", "KU", "KG", "LA", "LG", "LE", "LT", "LI", "LY", "LS", "LH", "LU", "MC", "MK", "MA", "MI", "MY", "MV", "ML", "MT", "IM", "RM", "MR", "MP", "MX", "MQ", "MD", "MN", "MG", "MJ", "MH", "MO", "MZ", "WA", "NR", "BQ", "NP", "NL", "NC", "NZ", "NU", "NG", "NI", "NE", "NF", "CQ", "NO", "MU", "OC", "PK", "PS", "LQ", "PM", "PP", "PF", "PA", "PE", "RP", "PC", "PL", "PO", "RQ", "QA", "RO", "RS", "RW", "TB", "RN", "WS", "SM", "TP", "SA", "SG", "RI", "SE", "SL", "SN", "NN", "LO", "SI", "BP", "SO", "SF", "SX", "OD", "SP", "PG", "CE", "SH", "SC", "ST", "SB", "VC", "SU", "NS", "SV", "WZ", "SW", "SZ", "SY", "TW", "TI", "TZ", "TH", "TO", "TL", "TN", "TD", "TS", "TU", "TX", "TK", "TV", "UG", "UP", "AE", "UK", "UY", "UZ", "NH", "VE", "VM", "VQ", "WQ", "WF", "WI", "YM", "ZA", "ZI"
Email	string	Optional Email address of the Business. Size Range: ..100
Address	object	Primary address of the business.
Address1	string	Street address or PO Box of the business. Size Range: 46
Address2	string	Optional Suite or apartment number of the business. Size Range: 46
City	string	City of the business. Size Range: 50
ProvinceOrState	string	Province or state name of the business. When the country code is US: Allowed values "AL", "AK", "AZ", "AR", "CA", "CO", "CT", "DE", "DC", "FL", "GA", "HI", "ID", "IL", "IN", "IA", "KS", "KY", "LA", "ME", "MD", "MA", "MI", "MN", "MS", "MO", "MT", "NE", "NV", "NH", "NJ", "NM", "NY", "NC", "ND", "OH", "OK", "OR", "PA", "RI", "SC", "SD", "TN", "TX", "UT", "VT", "VA", "WA", "WV", "WI", "WY", "AS", "FM", "GU", "MH", "MP", "PW", "PR", "VI", "AA", "AE", "AP" When the country code is CA: Allowed values "AB", "BC", "MB", "NB", "NL", "NT", "NS", "NU", "ON", "PE", "QC", "SK", "YT" Note: The size range is set to 50 for all countries except the United States and Canada.
ZipCd	string	ZIP code of the business. Size Range: 5-16
Country	string	2-character country code of the business. Allowed values "US","AF", "AX", "AL", "AG", "AQ", "AN", "AO", "AV", "AY", "AC", "AR", "AM", "AA", "AT", "AS", "AU", "AJ", "BF", "BA", "FQ", "BG", "BB", "BO", "BE", "BH", "BN", "BD", "BT", "BL", "BK", "BC", "BV", "BR", "IO", "VI", "BX", "BU", "UV", "BM", "BY", "CB", "CM", "CA", "CV", "CJ", "CT", "CD", "CI", "CH", "KT", "IP", "CK", "CO", "CN", "CF", "CG", "CW", "CR", "CS", "IV", "HR", "CU", "UC", "CY", "EZ", "DA", "DX", "DJ", "DO", "DR", "TT", "EC", "EG", "ES", "EK", "ER", "EN", "ET", "FK", "FO", "FM", "FJ", "FI", "FR", "FP", "FS", "GB", "GA", "GG", "GM", "GH", "GI", "GR", "GL", "GJ", "GQ", "GT", "GK", "GV", "PU", "GY", "HA", "HM", "VT", "HO", "HK", "HQ", "HU", "IC", "IN", "ID", "IR", "IZ", "EI", "IS", "IT", "JM", "JN", "JA", "DQ", "JE", "JQ", "JO", "KZ", "KE", "KQ", "KR", "KN", "KS", "KV", "KU", "KG", "LA", "LG", "LE", "LT", "LI", "LY", "LS", "LH", "LU", "MC", "MK", "MA", "MI", "MY", "MV", "ML", "MT", "IM", "RM", "MR", "MP", "MX", "MQ", "MD", "MN", "MG", "MJ", "MH", "MO", "MZ", "WA", "NR", "BQ", "NP", "NL", "NC", "NZ", "NU", "NG", "NI", "NE", "NF", "CQ", "NO", "MU", "OC", "PK", "PS", "LQ", "PM", "PP", "PF", "PA", "PE", "RP", "PC", "PL", "PO", "RQ", "QA", "RO", "RS", "RW", "TB", "RN", "WS", "SM", "TP", "SA", "SG", "RI", "SE", "SL", "SN", "NN", "LO", "SI", "BP", "SO", "SF", "SX", "OD", "SP", "PG", "CE", "SH", "SC", "ST", "SB", "VC", "SU", "NS", "SV", "WZ", "SW", "SZ", "SY", "TW", "TI", "TZ", "TH", "TO", "TL", "TN", "TD", "TS", "TU", "TX", "TK", "TV", "UG", "UP", "AE", "UK", "UY", "UZ", "NH", "VE", "VM", "VQ", "WQ", "WF", "WI", "YM", "ZA", "ZI"
ContactDetails	object[]	Details of the person the IRS can contact regarding the given business.
FirstNm	string	First name of the contact person. Size Range: 20
MiddleNm	string	Optional Middle name of the contact person. Size Range: 20
LastNm	string	Last name of the contact person. Size Range: 20
Suffix	string	Optional The suffix of the contact person. Allowed values "Jr", "Sr", "I", "II", "III", "IV", "V", "VI", "VII"
Phone	string	Optional Phone number of the contact person. Size Range: 10 digits
PhoneExtn	string	Optional Phone extension number. Size Range: 5
Email	string	Optional Email address of the contact person. Size Range: ..100
Fax	string	Optional Fax number of the contact person. Size Range: 10 digits
ReturnData	Object	Contains the return information.
BusinessType	String	Legal structure of the business. Allowed values "ESTE", "PART", "CORP", "EORG", "SPRO"
SigningAuthority	Object	Details of the person authorized to sign the return. Mandatory for 94x forms.
FirstNm	String	First name of the signatory. Size Range: 20
MiddleNm	String	Optional Middle name of the signatory. Size Range: 20
LastNm	String	Last name of the signatory. Size Range: 20
Suffix	String	Optional The suffix of the signatory. Allowed values "Jr", "Sr", "I", "II", "III", "IV", "V", "VI", "VII"
Phone	String	Optional Phone number of the signatory. Size Range: 10
PhoneExtn	String	Optional Phone extension number of the signatory. Size Range: 5
BusinessMemberType	String	Optional Title or role of the signatory. Allowed values "CORPORATESECRETARY", "SECRETARYTREASURER", "PARTNER", "GENERALPARTNER", "LIMITEDPARTNER", "LLCMEMBER", "MANAGINGMEMBER", "MANAGER", "TAXMATTERPARTNER", "PRESIDENT", "VICEPRESIDENT", "CORPORATETREASURER", "TREASURER", "ASSISTANTTREASURER", "CHIEFACCOUNTINGOFFICER", "CHIEFEXECUTIVEOFFICER", "CHIEFFINANCIALOFFICER", "TAXOFFICER", "CHIEFOPERATINGOFFICER", "CORPORATEOFFICER", "EXECUTIVEDIRECTOR", "DIRECTOR", "CHAIRMAN", "EXECUTIVEADMINISTRATOR", "RECEIVER", "PASTOR", "ASSISTANTTORELIGIOUSLEADER", "REVEREND", "PRIEST", "MINISTER", "RABBI", "LEADEROFRELIGIOUSORGANIZATION", "SECRETARY", "DIRECTOROFTAXATION", "DIRECTOROFPERSONNEL", "ADMINISTRATOR", "EXECUTOR", "TRUSTEE", "FIDUCIARY", "OWNER", "SOLEPROPRIETOR", "MEMBER", "SOLEMEMBER", "REPORTINGAGENT"
ReturnData	Object	Contains the return information.
FormIL340	Object	Identifies the Form IL 3/40 data.
IsFinalReturn	Boolean	If true, identifies that the business has ceased operations or had no employees during that quarter.
IsNoWageRptd	Boolean	When true, indicates that no wage is reported in this quarter.
UIIdNum	String	Employer's Illinois Unemployment Account Number. Size Range: 8 digits Sample Format: "99999999"
EmployerTaxType	String	Employment tax type. Allowed values "TAXABLE_EMPLOYER", "REIMBURSABLE_EMPLOYER"
TotGrossWages	Number	Total wages paid for the quarter. Size Range: 0-99999999999.99
TotExcessWages	Number	Total excess wages paid for the quarter. Size Range: 0-99999999999.99
TotTaxableWages	Number	Total taxable wages paid for all employees in the quarter that is subject to Illinois Unemployment Insurance. Size Range: 0-99999999.99
UITaxRate	Number	Tax rate for the quarter. Size Range: 1-100
UITaxDue	Number	Contribution amount for the quarter. Size Range: 0-99999999.99
Interest	Number	Optional Interest due for the quarter (2% per month after the due date). Size Range: 0-99999999.99
LateFilingPenalty	Number	Optional Late filing penalty for the quarter. Size Range: 0-99999999.99
UnderPayment	Number	Optional Late filing penalty for the quarter. Size Range: 0-99999999.99
OverPayment	Number	Optional Late filing penalty for the quarter. Size Range: 0-99999999.99
TotUIDue	Number	Total remittance due for the quarter. Size Range: 0-99999999.99
NumOfEmp	Object	Identifies the total number of employees for the quarter.
TotMonth1Emp	string	Total number of employees in month 1 of the quarter. Size Range: 0-9999999
TotMonth2Emp	string	Total number of employees in month 2 of the quarter. Size Range: 0-9999999
TotMonth3Emp	string	Total number of employees in month 3 of the quarter. Size Range: 0-9999999
EmployeeDetails	Object[]	Object to identify the employee details.
EmployeeSequenceId	string	A unique number to identify this record. Size Range: 1-10
EmployeeId	Guid	Optional A unique ID generated by TaxBandits after the return is created. Size Range: ..10
EmployeeRef	string	A unique identifier of the employee. Size Range: 1-50
SSN	string	Employee's Social Security Number (SSN). Size Range: 9-11
FirstNm	string	Employee's first name. Size Range: 1-15
MiddleNm	string	Optional Employee's middle name. Size Range: 1-15
LastNm	string	Employee's last name. Size Range: 1-20
Suffix	string	Optional Employee's suffix. Allowed values "Jr", "Sr", "I", "II", "III", "IV", "V", "VI", "VII"
GrossWages	Number	Total gross wages reported for the quarter. Size Range: 0-99999999999.99
Address	object	Address information of the employee.
Address1	string	Street address or PO Box of the employee. Size Range: 46
Address2	string	Optional Suite or apartment number of the employee. Size Range: 46
City	string	City of the employee. Size Range: 50
ProvinceOrState	string	Province or state name of the employee. Size Range: 50
ZipCd	string	ZIP code of the employee. Size Range: 5-16
Country	string	2-character country code of the employee.

Response Body

Field	Type	Description
SubmissionId	Guid	Unique identifier for a submission.
SuccessRecords	object[]	Provides detailed information about the success status of Form IL 3/40 records.
SequenceId	string	A unique reference ID for the submission that can be used to identify a particular record. The Sequence ID will be returned in the response for your reference.
BusinessId	Guid	Unique identifier for the business (payer) generated by TaxBandits.
PayerRef	string	Unique identifier for the business (payer) provided by you.
RecordId	Guid	A unique identifier generated by TaxBandits when a Form IL 3/40 return is created.
FormType	string	Type of form.
EmployeeData	object[]	Object to identify the employee details.
EmployeeId	Guid	Returns the unique identifier of the employee generated by TaxBandits.
Status	string	Returns the record status.
StatusTs	string	Returns the date and time when the return was created.
Info	string	Provides additional information about the return.
Errors	object[]	Displays error information related to the state returns of Form IL 3/40.
Id	string	Returns the validation error ID.
Name	string	Name of the validation error.
ErrorRecords	object[]	Provides detailed information about the error status of Form IL 3/40 records.
SequenceId	string	A unique reference ID for the submission that can be used to identify a particular record. The Sequence ID will be returned in the response for your reference.
RecordId	Guid	Unique identifier for the record.
Errors	object[]	Displays detailed error information.
Id	string	Returns the validation error ID.
Name	string	Name of the validation error.
Message	string	Description of the validation error.

Request JSON

Sample 1

Return with Business as EIN and US address

{
  "StateUIRecords": [
      {
          "SequenceId": "001",
          "ReturnHeader": {
              "TaxYear": "2026",
              "Qtr": "Q3",
              "Business": {
                  "IsDefaultBusiness": true,
                  "TINDetails": {
                      "Format": "PLAIN_TIN",
                      "TINType": "EIN",
                      "TIN": "48-7789899"
                  },
                  "BusinessNm": "Snowdaze LLC",
                  "NameCtrl": "FIRE",
                  "DBADetails": {
                      "DBANm": "Iceberg Icecreams",
                      "DBARef": "DBA1001",
                      "DBAId": null,
                      "Address": {
                          "Address1": "123 Main St",
                          "Address2": "Suite 1001",
                          "City": "Rock Hill",
                          "ProvinceOrState": "SC",
                          "ZipCd": "29730",
                          "Country": "US"
                      }
                  },
                  "Address": {
                      "Address1": "123 Main St",
                      "Address2": "Suite 1001",
                      "City": "Rock Hill",
                      "ProvinceOrState": "SC",
                      "ZipCd": "29730",
                      "Country": "US"
                  },
                  "ContactDetails": {
                      "FirstNm": "James",
                      "MiddleNm": "A",
                      "LastNm": "Anderson",
                      "Suffix": "Jr",
                      "Phone": "8035551234",
                      "PhoneExtn": "101",
                      "Email": "contact@snowdaze.com",
                      "Fax": "8035555678"
                  },
                  "BusinessType": "ESTE",
                  "SigningAuthority": {
                      "FirstNm": "Ambrane",
                      "MiddleNm": "A",
                      "LastNm": "Cavil",
                      "Suffix": "Jr",
                      "Phone": "8035551000",
                      "PhoneExtn": "111",
                      "BusinessMemberType": "ADMINISTRATOR"
                  }
              }
          },
          "ReturnData": {
              "FormIL340": {
                  "IsFinalReturn": false,
                  "IsNoWageRptd": false,
                  "UIIdNum": "8934567",
                  "EmployerTaxType": "TAXABLE_EMPLOYER",
                  "TotGrossWages": 2000,
                  "TotExcessWages": 2000,
                  "TotTaxableWages": 0,
                  "UITaxRate": 1,
                  "UITaxDue": 0,
                  "Interest": 100,
                  "LateFilingPenalty": 100,
                  "UnderPayment": 100,
                  "OverPayment": 100,
                  "TotUIDue": 200,
                  "NumOfEmp": {
                      "TotMonth1Emp": 2,
                      "TotMonth2Emp": 2,
                      "TotMonth3Emp": 2
                  },
                  "EmployeeDetails": [
                      {
                          "EmployeeSequenceId": "01",
                          "EmployeeRef": null,
                          "SSN": "313-21-6277",
                          "FirstNm": "John",
                          "MiddleNm": "A",
                          "LastNm": "Smith",
                          "Suffix": "Sr",
                          "GrossWages": 1000,
                          "Address": {
                              "Address1": "12 Main St",
                              "Address2": "CC Avenue",
                              "City": "Rock Hill",
                              "ProvinceOrState": "SC",
                              "ZipCd": "29730",
                              "Country": "US"
                          }
                      },
                      {
                          "EmployeeSequenceId": "02",
                          "EmployeeRef": null,
                          "SSN": "843-81-2651",
                          "FirstNm": "Marcellus",
                          "MiddleNm": "A",
                          "LastNm": "Smith",
                          "Suffix": "Sr",
                          "GrossWages": 1000,
                          "Address": {
                              "Address1": "12 Main St",
                              "Address2": "CC Avenue",
                              "City": "Rock Hill",
                              "ProvinceOrState": "SC",
                              "ZipCd": "29730",
                              "Country": "US"
                          }
                      }
                  ]
              }
          }
      }
  ]
}

Response JSON

Success Response - This is a sample response for successful API requests.

{
  "SubmissionId": "01a0e764-91af-77bb-9989-cf6132651091",
  "SuccessRecords": [
      {
          "SequenceId": "001",
          "BusinessId": "19fc85b0-7bf6-45d3-8bde-659e007a8047",
          "PayerRef": null,
          "RecordId": "01a0e764-98ad-74f3-ae90-d846c08a696f",
          "FormType": "IL340",
          "EmployeeData": [
              {
                  "EmployeeId": "62b3650b-d22b-4cf0-b8b2-515047456cbf"
              },
              {
                  "EmployeeId": "7f38051b-a6aa-4eea-ae0e-e9d09ae8eb06"
              }
          ],
          "Status": "CREATED",
          "StatusTs": "2026-09-28 05:42:04 -04:00",
          "Info": null,
          "Errors": null
      }
  ],
  "ErrorRecords": null,
  "Errors": null
}

W-9/W-8 Automation

1099 Automation

TIN Matching

W-2 Automation

941/940 Automation

1098-T Automation

ACA Automation

Extension Automation

1042-S Automation

Supported Forms

Gig Software

Payroll Software

Affiliate Software

HOA Software

Reselling Platform

HCM Providers

Property Management

Healthcare Market Research Platforms

Create

Create

Request Body

Response Body

Request JSON​

Response JSON​

Request JSON

Response JSON