Test Drive

Run it on a return you already filed.

Upload last year's return and this year's documents. You get a provisional refund or balance-due estimate, the open items, and one Excel workbook with every number traced to its source. Then upload the return you filed and see where they differ.

Start free Download the sample workbook

First Standard workbook free, first comparison included. Firm email, no card.

The Summary tab of a Lunar Papers workbook: estimated refund, open items, status, and the headline figures, each linked to the tab behind it

The Summary tab of the sample workbook. Fictional taxpayer; every figure is a live link to the schedule behind it.

Two minutes, start to finish

Upload, estimate, workbook, comparison. One engagement, on screen.

Narrated by an AI-generated voice (not a real person's). The client, documents and figures are fictional.

Three steps, on a return you know the answer to

Pick a 2025 return you've already filed. Your own is the simplest. You already know what it should say, so you can judge the work properly.

STEP 1

Upload

The 2024 return and the 2025 tax documents as PDFs. Up to 15 documents, 3 K-1s and 2 brokerage accounts fit the free workbook.

STEP 2

Read

The provisional estimate beside last year's, the documents identified and filed, the missing ones named, a drafted client request, and the workbook.

STEP 3

Compare

Upload the 2025 return you filed. Each possible difference shows the workpaper amount, the return amount, and where to look in your tax software.

What to look for

Did it identify every document you uploaded, and name the ones that were missing?
Where the estimate differs from what you filed, can you see why from the workbook's source references?
Do the flagged differences hold up when you look at them?
Would the open items and the drafted client request have saved you a round of emails?

Free to tryOne Standard workbook and its first return comparison. After that, from $79 per 1040 and $99 per business return. No subscription.

A return-comparison finding: workpaper amount, prepared-return amount, the difference, and where to look in your tax software

One finding from a return comparison. Fictional client, illustrative figures.

Questions

What does the test drive cost?

Nothing. Your first Standard workbook is free, and its first return comparison is included. After that, engagements are priced by the size of the return, from $79 per 1040 and $99 per business return, with return comparisons priced separately.

Whose return should I use?

One you know well. Your own return is the simplest, since no one else's information is involved. For a client's return, treat Lunar Papers as you would any software provider that handles tax return information (Section 7216). Each firm's files are kept separately, encrypted, and deleted on the schedule you set, and tax return information is never used to train AI. The Security page has the details.

Who makes the tax determinations?

Your firm does. Estimates are provisional and based on the documents provided, and each possible difference is evaluated by your preparer. Lunar Papers, LLC is a software company, not a CPA firm.