Can I fill out my own IL financial affidavit?

If you are reading this on a Sunday night with the Illinois 13.3.1 PDF open in another tab, wondering whether you have to pay an attorney $2,500 to do something that looks like a glorified tax return, the answer is no. You can absolutely fill out your own 13.3.1. The Illinois Supreme Court designed the form to be self-fillable. Tens of thousands of Illinois parents complete it themselves every year.

But "can" is not the same as "should without help." This page tells you exactly what is involved, where most DIY filers go wrong, and how to decide whether you should still loop in an attorney for review.

The honest time commitment

For a typical Illinois parent with one or two bank accounts, a W-2 job, and a normal household budget, a first draft of the 13.3.1 done by hand from scratch takes 15 to 30 hours across two or three weekends. If you have multiple income sources, a small side business, or complicated retirement accounts, the time roughly doubles.

That number surprises people. The form itself is only 14 pages. The reason it takes so long is that almost none of the time is actually spent writing on the form. It is spent assembling the source documents, doing the arithmetic to get from raw bank-statement transactions to clean monthly averages, and tracking down the one statement you cannot find in your email.

Specifically, here is where the 15 to 30 hours typically go:

• Gathering documents from your bank, employer, retirement custodian, mortgage company, child-support clerk: 4 to 8 hours.
• Reading three months of bank statements and categorizing every transaction into the 13.3.1 expense buckets: 5 to 10 hours.
• Reconciling pay stubs against W-2s and figuring out which gross-income figure the form wants: 2 to 4 hours.
• Filling out the actual form, drafting affidavit exhibits, double-checking math: 4 to 8 hours.

Plan accordingly. Do not start this on the Thursday before your Monday hearing.

The documents you need before you start

Have these in front of you before you open the form. Going back to dig out a statement halfway through is what turns a 15-hour project into a 30-hour project.

• Last two years of federal tax returns (with all schedules and the actual filed PDF, not just a summary).
• Three months of pay stubs from every income source. If you are paid biweekly that is six stubs. If you have a second job, six more.
• Three months of complete bank statements for every checking and savings account in your name (or joint).
• Most recent statement from every retirement account, brokerage account, HSA, and 529 plan.
• Lease or mortgage statement showing current monthly housing cost.
• Auto loan statements and registration for every vehicle in your name.
• Most recent statements from every credit card and personal loan, showing balance and minimum monthly payment.
• Your current child-support order if there is one in place.
• Health, dental, vision, life, and disability insurance declarations showing monthly premium.
• Receipts or statements for any recurring expense over $100 a month that does not show on a bank statement (cash payments for childcare, for instance).

Yes, it is a lot. Yes, gathering it takes a weekend. This is the part that does not get easier no matter how good your software is — the documents have to exist before anything can read them.

The four mistakes that get parents in trouble

I have helped review 13.3.1 drafts from a couple dozen Illinois parents at this point. These four mistakes show up in roughly half of every DIY draft I see.

Mistake 1: Gross vs net confusion on income

Line 5 of the 13.3.1 wants gross monthly income. Line 7 wants net monthly income after specific deductions enumerated by Illinois statute. Most DIY filers put their take-home pay on line 5 and leave line 7 effectively blank, or they fill line 7 with the same number they put on line 5.

This is the single mistake opposing counsel catches first. It looks like you are hiding income. Even if you are not, you have just handed the other side a free credibility hit. The 13-3-1 line-by-line guide walks the exact deductions the statute allows, with the source statute references, so you can do the math correctly.

Mistake 2: Leaving line 14 blank

Line 14 asks for your monthly debt service — the total monthly payment you make on every debt you owe. Not the balance. The payment. Many DIY filers see "debt" and write down their total credit-card balance, which goes on a different line (the asset/liability schedule, not the monthly cash-flow section).

Leaving line 14 blank or wrong makes your net cash position look better than it is. If you are asking the court for maintenance or trying to argue you cannot afford the proposed support, an incorrect line 14 actively hurts your case.

Mistake 3: Missing recurring cash expenses

Childcare paid in cash. The babysitter you pay $400 a month in Venmo with no memo. The lawn service you pay $80 in cash every two weeks during the season. Most DIY filers only write down the expenses that show on a bank statement, because those are the ones that are easy to find.

The 13.3.1 wants every recurring expense over a normal threshold, not just the ones with a paper trail. Sit down with your calendar and your last three months mentally — what cash did you actually spend on a recurring basis? Write it down. The form has a line for it.

Mistake 4: One bank statement, not three

Some Illinois counties want three months of statements as supporting exhibits. Others want six. A handful of judges have started asking for twelve. The local court rule varies. DIY filers tend to attach the most recent month and assume that covers it.

Before you file, check the local rules of the circuit where your case sits, or ask the clerk what that judge typically requires. If the answer is "six months" and you attached one, you are filing an incomplete disclosure.

When to stop DIY and call someone

You should still draft the 13.3.1 yourself in most cases. You know your finances better than anyone. But you should stop and get help if:

• You own a business, even a small one, with revenue over about $50,000 a year. Business income classification on the 13.3.1 is its own subject. Get a forensic accountant or a family-law attorney with small-business experience.
• You have significant retirement assets you and your spouse will split. The form has a line for them but the actual division (QDRO) is a separate document and easy to get wrong.
• Your case is high-conflict and you expect opposing counsel to attack your disclosure aggressively. You need a lawyer to backstop your draft.
• You have inherited assets or premarital property and you need to argue some of it is non-marital. The 13.3.1 has classification fields for this and they have to match the rest of your case theory.

For everyone else, DIY is realistic, and a review-only consult with an Illinois family-law attorney at $250 to $600 will catch the line-classification mistakes before you sign. That is the cheapest insurance in family law.

Where Casefile fits

Casefile collapses the 15 to 30 hours into something closer to 90 minutes for a typical case. You upload your documents. Casefile reads your bank statements and categorizes the transactions. It parses your pay stubs into the gross-vs-net structure the form requires. It populates the lines you would otherwise fill by hand, with each number traceable to the source document it came from.

You still review every number. You still sign. You still hand it to your attorney for review. But you do not have to spend three weekends transcribing bank statements into spreadsheet cells.

The 13.3.1 line-by-line guide walks each section of the form in detail. The founder story explains why this product exists.