An affidavit of domestic partnership in Illinois is a sworn, notarized statement that two unmarried adults sign to declare they live together in a committed relationship. You file it with the entity that will accept it — usually an employer’s benefits office or a municipal registry — because Illinois has no statewide domestic partnership law. The affidavit opens the door to things like partner health insurance or a local registry certificate. It does not create marriage-level legal rights.
What the Affidavit Actually Gets You
Before you file anything, understand the scope. Illinois recognizes marriage and civil unions at the state level, but not domestic partnerships. A domestic partnership exists only where a specific city, county, or employer chooses to recognize one, and the benefits are limited to whatever that entity offers.1Illinois General Assembly. 750 ILCS 75 – Illinois Religious Freedom Protection and Civil Union Act In practice that usually means health insurance enrollment for your partner, sometimes bereavement leave or facility access, and a public record of the relationship if you register with a municipality.
What the affidavit does not give you: inheritance rights if your partner dies without a will, property division if the relationship ends, automatic authority to make medical decisions for your partner, Social Security survivor benefits, or the right to refuse to testify against each other in court. If any of that matters to you, you need separate estate planning documents — a will, a healthcare power of attorney, and a financial power of attorney — or a civil union or marriage. The affidavit is narrow by design.
Municipalities including Urbana, Oak Park, and Champaign maintain their own registries, each with its own rules.2City of Urbana, Illinois. Domestic Partnership Registration Cook County’s Clerk office handles records for Chicago and suburban Cook County.3Cook County. Marriage Certificates Outside of local programs, most affidavits in Illinois are employer-specific forms used for benefits enrollment.
Who Can File
Eligibility rules vary by employer and municipality, but most Illinois programs require that both partners:
- Are at least 18 years old and legally capable of entering a contract.
- Share a permanent residence and are jointly responsible for each other’s basic living expenses.
- Are not married, in a civil union, or in another domestic partnership with anyone else.
- Are not related by blood in any way that would prohibit marriage under Illinois law.
- Intend to remain in the relationship indefinitely.
Urbana’s registry requires all of the above and bars anyone who already has a registered partner or legal spouse.2City of Urbana, Illinois. Domestic Partnership Registration
Many employer plans add a minimum cohabitation period. Blue Cross and Blue Shield of Illinois requires six months of living together before you can file.4Blue Cross and Blue Shield of Illinois. Affidavit of Domestic Partnership The University of Illinois uses the same threshold.5University of Illinois. Affidavit of Domestic Partnership If a prior partnership ended, some plans also require a waiting period, commonly six months, before you can file a new affidavit with a different partner.
What to Gather Before You File
Regardless of where you’re filing, you’ll be asked for both partners’ full legal names as they appear on government ID, your shared residential address, and the date you began living together.6City of Urbana, Illinois. Registration of Domestic Partnership Affidavit Phone numbers and email addresses are common additions.
Most programs also want proof of financial interdependence. Have two or three of the following ready:
- A joint lease or mortgage statement listing both names.
- Utility bills at the shared address showing both partners.
- Joint bank account or credit card statements.
- Shared car insurance or renter’s insurance policies.
You rarely need every item, but assembling a few in advance avoids follow-up requests from a benefits office or a clerk.
Signing and Notarizing the Affidavit
Get the form from the entity that will receive it. For employer benefits, that’s your HR department. For a municipal registry, it’s the city clerk’s office. A generic form pulled off the internet is not a safe substitute; the recipient’s own form includes the specific language and attestations they require.
Both partners must sign in front of a commissioned Illinois notary public, with valid government-issued photo ID for each. Under the Illinois Notary Public Act, the maximum fee for a standard notarial act is $5. Electronic notarization and remote online notarization each cap at $25.7Illinois General Assembly. Illinois Compiled Statutes 5 ILCS 312 – Illinois Notary Public Act, Section 3-104 A mobile notary who comes to you can charge a separate travel fee that isn’t regulated, so confirm the total before you book.
Check every field before the notary stamps the document. Names, address, and the start date of your cohabitation should match your supporting documents exactly. Errors caught after signing mean a new form and another notary visit.
Where to File
With an Employer
If you’re enrolling a partner in health insurance or other workplace benefits, submit the notarized affidavit and supporting documents to your benefits administrator, typically through HR. Enrollment windows vary. Some employers allow domestic partner enrollment only during open enrollment or within 30 days of establishing the partnership, so ask about deadlines before you start the paperwork.
With a Municipal Registry
If your city maintains a registry, file the notarized affidavit with the city clerk. Urbana charges a $40 registration fee.6City of Urbana, Illinois. Registration of Domestic Partnership Affidavit Fees elsewhere vary; call your clerk for current pricing. After the clerk reviews the affidavit, you’ll usually receive a certificate or formal confirmation.
One point people often miss: records filed with a municipal registry are generally public. Urbana explicitly states that your record of partnership is public information.2City of Urbana, Illinois. Domestic Partnership Registration Factor that in if privacy matters.
Keep copies of everything you file: the signed affidavit, supporting documents, any certificate or confirmation letter, and your fee receipt. You may need them later for a job change, a new benefits application, or to prove the partnership to a third party.
Tax Consequences You Should Know About
The federal government does not recognize domestic partnerships for tax purposes. Domestic partners cannot file jointly; the IRS limits “married filing jointly” and “married filing separately” to legally married couples.8Internal Revenue Service. Filing Status You file as single or, if you qualify, head of household. Illinois requires taxpayers to use the same filing status on the state return as on the federal return, so your Illinois return follows suit.9Illinois Department of Revenue. Filing Status – IL-1040, Individual Income Tax Return
When your employer pays part of your domestic partner’s health insurance premium, the IRS treats that contribution as taxable income to you. This imputed income shows up on your W-2 and raises your tax bill, even though you never see the cash. Your own premium contributions for your partner’s coverage come out of post-tax dollars, unlike the pre-tax treatment that married spouses get. The one exception: if your partner qualifies as your tax dependent under Section 152 of the Internal Revenue Code, imputed income does not apply.10Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined A partner working full-time generally won’t qualify, but a low-income partner might; the numbers are worth running.
Ending the Partnership
Filing creates an obligation to unfile. If you registered with a municipality, submit an affidavit of termination to the same clerk. Either partner can file; both can file together or separately. Urbana requires the termination affidavit within 30 days of the change in partnership status and charges a $30 filing fee.2City of Urbana, Illinois. Domestic Partnership Registration A registered partnership also ends automatically if either partner dies.
For an employer-based affidavit, notify HR as soon as the relationship ends. Coverage for your former partner will be terminated, often within a set window such as 30 days. Letting the clock run while a former partner keeps receiving benefits through your employer can expose you to fraud liability and demands to repay premiums.
If you plan to register a new partnership later, check the waiting period. Six months is common before you can file a new affidavit with a different partner.4Blue Cross and Blue Shield of Illinois. Affidavit of Domestic Partnership