Taxpreparer guide: California and Illinois e-filing mandates

This taxpreparer guide covers the e-filing mandates that apply to paid preparers in California and Illinois, from each state's volume trigger to the consent record that supports a paper return.

What to take away

How the two mandates differ at the trigger

California's mandate sits in Cal. Rev. & Tax. Code section 18621.5 and is run by the Franchise Tax Board. It reaches a paid preparer who filed more than 11 accepted California individual returns in the prior calendar year.

Cross that line and paper filing closes for the returns in scope. FTB Publication 1345, the handbook for authorized e-file providers, restates the trigger and the opt-out statement your client has to sign.

Illinois keys its individual mandate to a paid preparer who prepared more than 10 Illinois individual income tax returns (Form IL-1040) and used commercial software to prepare them. The rule sits in 86 Ill. Adm. Code 760.100 and in the Department's IL-1040 e-file guidance.

The software condition does real work. A preparer who completes returns by hand is not pulled in the same way. Almost every practice uses commercial software, so in practice the condition is met.

That single difference explains most of the confusion. California counts returns filed. Illinois counts returns prepared. A firm can be under one trigger and over the other without changing anything about how it works.

Both figures are current for the 2026 filing season, and both states revisit forms and thresholds. Verify the number each year, and note the figure you checked and the date, in case a reviewer asks.

California: counting accepted returns

The California count follows the return, not the client's address. A nonresident return you prepare for a client who moved to Arizona still lands in the tally if you filed it.

The opt-out is where practices get caught. A client who does not want an electronic return must sign a statement, and you keep it. A verbal request is not enough. A sentence in the engagement letter is not a substitute. The statement identifies the taxpayer and the tax year, and it is signed and dated.

Most commercial software transmits the California return alongside the federal one through the federal/state program. That convenience hides a problem: your federal and state consents get captured in the same session, and a preparer moving fast can capture one and miss the other.

Track the accepted-return count monthly, not in April. A practice that crosses the 11-return line mid-season has to switch its remaining California returns to electronic filing, which is a bad week to learn a new transmission workflow. Put the count where you can see it, alongside the rest of your tech stack and performance metrics.

A new practice can treat its first season as a counting year. Paper returns all season are fine if you finish at 11 or under. The count from that season decides your obligation for the next one.

Illinois: two counts, not one

Illinois also requires electronic filing for certain business returns prepared by a paid preparer, including corporate returns (IL-1120) and partnership returns (IL-1065), once the applicable volume is met. This is the requirement that surprises multi-state firms.

A practice that files a dozen Illinois partnership returns on extension may never think about the individual mandate and still owe electronic filing on the business side. Check both counts separately, and assign one person to own the business count so it does not live in someone's head.

Extensions move the due date, not the filing method. A return that must be filed electronically in April must still be filed electronically in October.

The Department posts filing updates, deadline changes and system notices through its news page. The Illinois Department of Revenue news page is worth a standing bookmark for anyone filing Illinois returns.

Illinois accepts returns through the federal/state program and runs its own channels, including IL-1040 filing through MyTax Illinois. Confirm which channel your software uses before you promise a client a transmission date.

Side-by-side comparison of mandate triggers and thresholds

Three consequences follow. A practice can be under one trigger and over the other in the same season. Entity work can create an obligation that 1040 work does not. And consent documentation is not portable: a California statement does not satisfy Illinois, and an Illinois software flag does not satisfy California.

The federal layer sits under both. The IRS explains preparer filing channels on its file your tax return guide page. State mandates stack on top of that framework rather than replacing it.

Software settings that carry both states

Support for both states is not the same as configuration for both states. Lacerte, ProConnect Tax, UltraTax CS, Drake Tax and CCH Axcess all handle California and Illinois returns. Fewer arrive configured for two different consent models.

Start with the counters. Your software should report accepted federal returns, accepted California returns and prepared Illinois returns as three separate figures. One total means you are estimating, and estimating is how a practice gets surprised in March.

Then the consent workflow. California needs a signed statement you can store and retrieve. Illinois needs a per-return refusal flag that prints or transmits with the return record. Confirm both exist before you need them, not during a client meeting.

Run a test return in each state with an intentional paper-filing selection and read what the software says. A package that lets you paper file a mandated return without a warning will let a seasonal preparer do it too. The things to check in tax preparation software list is a reasonable starting point for that evaluation.

Check the state update cadence. Both states change forms and thresholds, and a package that updates late in January creates rework in the first week of February. Confirm your EFIN and PTIN records are current as well. A lapsed PTIN stops transmissions no matter how well the state settings are configured.

Where the return is prepared does not matter. A seasonal preparer in Texas preparing a California return still creates a firm obligation. Train every preparer on both states.

Free filing channels are not a substitute for a professional package. The IRS free file program rules are aimed at individual filers, and they are worth knowing when a client asks why they cannot simply use them.

Consent records and retention

Consent is the most common audit exposure in both states, and the two states want different paper. Treat consent as a workflow step, not a conversation.

In California, the client signs a statement electing not to file electronically, and you keep it for four years from the return due date. If it is missing, you have no defense for a paper return that should have gone out electronically.

In Illinois, the refusal is captured in the software and the paper return is retained. There is no separate state form to sign in most cases, which makes the step easy to skip. Skipping it leaves the same gap.

Retention periods differ. Do not apply one destruction schedule to both states. Keep consent records for the longer of the two periods, or keep them all and stop tracking which is which.

Scan consent records into the same system as the return. A consent document that cannot be found during a review is functionally absent. Write the client script into your compliance checklist so new hires inherit it instead of inventing it.

Operational impact on review and delivery steps

Mandates change the shape of the season, not just the filing step.

Review changes most. A reviewer who checked math and forms now also checks that the correct filing method was selected and that consent documentation exists. Make it a line item, not a reminder.

Delivery changes too. Electronic filing means the client's copy goes out after acceptance, not at the signing meeting. Say so in the engagement letter so clients are not calling about a refund they have not received.

Follow-up is the last shift. Rejected returns come back fast and need a preparer who knows both states' error codes. Keep a short rejection triage list at the front of the workflow.

For practices still mapping the season end to end, the operations and workflow guide covers how returns move from intake to delivery and where mandate checks fit.

Growth adds a layer. A firm that opens a second state office inherits that state's mandate on day one, and the prior-year count follows the preparer, not the address. Plan tax preparation expansion with the mandate counts in view.

The IRS keeps a central hub for preparer guidance, including due diligence and e-file rules, at its tax professionals guidance hub. State mandates sit under that federal framework and rarely contradict it.

Common questions

Does California require e-filing for every preparer?

No. The requirement attaches to a paid preparer who filed more than 11 California individual returns in the prior year, under Cal. Rev. & Tax. Code section 18621.5. Below that trigger, paper filing remains available.

Is the Illinois mandate the same as California's?

No. Illinois keys the individual mandate to paid preparers who prepared more than 10 Illinois returns with commercial software, and it adds a separate electronic filing requirement for certain business returns. The two states also count different things: returns prepared in Illinois, returns filed in California.

Can a client simply refuse electronic filing?

Yes, but the paperwork differs. California requires a signed statement you keep. Illinois records the refusal per return in the software. Neither state accepts a verbal request.

What happens if a mandated return goes out on paper?

The return may be rejected or the preparer may face penalties, and the client's refund is delayed. Fix the filing method, document the correction, and confirm the current penalty schedule with the state authority rather than a secondhand figure.

Where do I check for Illinois filing updates?

The Illinois Department of Revenue posts seasonal guidance, deadline changes and system notices on its news page throughout the year.