What Does My Accountant Need for Taxes? An AI-Built Checklist

What does my accountant need for taxes? It depends on your entity type. A sole proprietor filing Schedule C needs different documents than an S corporation filing Form 1120-S. In every case the core is the same: complete bank and card statements, income forms, and prior-year returns. Quill's assistant builds the checklist from your books and shows what is ready.

Tax season starts with an email from your accountant: "Please send your documents." Then you spend a weekend hunting for statements, forms and answers. This guide lists what accountants typically ask for, by entity type, and shows how the assistant inside Quill turns it into a checklist built from your own books. It is part of our look at the AI financial assistant that does the work.

One boundary first: this is a document checklist, not tax advice. Your accountant decides what applies to you.

What does my accountant need for taxes, whatever my entity?

Every return needs a complete, accurate record of money in and out. These items come up for almost everyone:

• Every bank and credit card statement for the full year, with no missing months.
• Income forms you received, such as 1099s and W-2s.
• Last year's return.
• Records of loans, large purchases and anything that is not a simple expense.
• Answers to a few questions about your business type and ownership.

The first item is where most people stall. A single missing statement month makes the year incomplete. Quill flags missing statement months and statements that do not add up before they reach your accountant.

What do I send my accountant if I file Schedule C?

Sole proprietors and single-member LLCs that are not taxed as corporations report business profit or loss on Schedule C. The IRS describes it as the form for profit or loss from a business run by a sole proprietor. A typical document list:

• Business income records and any 1099-NEC or 1099-K forms.
• Business bank and card statements, kept apart from personal spending.
• Expense records you want your accountant to review.
• Records of estimated tax payments you made.
• Last year's return.

Keeping personal and business money apart saves the most time here. Quill's Business side keeps them separate.

What do I send my accountant if I have an S corporation?

An S corporation files its own return. The IRS explains that Form 1120-S is the return for entities that have elected S corporation status. Accountants commonly ask for:

• Business bank and card statements for the whole year.
• Payroll records and owner pay.
• Shareholder names, ownership percentages and any shareholder loans.
• 1099s issued and received.
• Loan and equipment purchase documents.
• The prior-year return.

C corporations (Form 1120), partnerships (Form 1065) and nonprofits (Form 990) have their own lists. Quill's tax prep covers these entity types: Schedule C, 1120-S, 1120, 1065 and 990.

How does Quill's AI build the checklist?

You ask a plain question, and the assistant checks your books. Try: "I have an S-Corp. What do I send my accountant?" Quill answers in three parts:

1. Ready: documents your books already cover, such as months with statements that add up.
2. Not ready: gaps, with dollar amounts and links to the exact screen, such as a missing month or unsorted charges.
3. What a statement cannot show: items that need your own records or answers.

The answer rests on figures Quill has already proved against your bank's printed statement totals, to the cent. If your data cannot answer something, it says "Not in your data" instead of guessing. That matters because AI can get money numbers wrong when it works from a blank chat.

What can the assistant change, and what can it not?

It can propose changes to your records, but nothing happens until you click. Each proposal states how many charges and how much money it touches, says "Nothing has happened yet," and Quill saves a safety backup before it applies. For tax prep it can record your answers (such as business type) and offer to build the year-end tax package.

It cannot delete statements or transactions, move money, pay bills or give tax or investment advice. For the broader rules, see the guardrails to demand from AI agents.

How do you make the handoff painless?

Start early and work from a list. A few habits make the biggest difference:

• Drop statements into your Quill folder as each month closes, so gaps show up in weeks, not at filing time.
• Sort uncategorized charges as you go. Quill lists how many are unsorted and how much money they cover.
• Ask your accountant for their own checklist once, then compare it with Quill's.
• Send your accountant the files in one pass. Quill can build the accountant reports, a QuickBooks file and a year-end tax package.

Fewer back-and-forth emails usually means a faster return and a smaller bill.

What does a bank statement never show?

A statement shows what moved, not why. Your accountant will still need things the statement cannot supply:

• Who a payment was for, and whether it was personal or business.
• Payroll forms and owner pay details.
• Shareholder loans and equity moves.
• Equipment or asset purchase paperwork.
• Cash income that never hit a statement.

Quill's checklist names these gaps so they do not surprise you in March.

Where does the AI run, and what does it see?

Be clear about the trade-off. Quill keeps your books on your computer and never uploads your PDF statements. The AI assistant is optional and runs in the cloud. When you ask it something, a summary of your finances goes to the provider you picked, which can be your own Claude or ChatGPT subscription or an API key. With AI off, none of your financial data leaves your computer. If you want the comparison with linked-account tools, read ChatGPT Finances vs Quill.