S Corporation 2025 Tax Prep Guide: What to Gather and How to Prepare for Filing – Heard

This guide walks you through what you’ll need to file your S Corporation Return (Form 1120s) and the tasks to complete before the end of 2025.

Tasks to Complete Before the End of 2025

1. Organizing your Year-End finances in Heard

Review any messages from your Heard team awaiting your reply
Go to Transactions>Needs review to action on any transactions your bookkeeping team has flagged as needing your input.
If you have business transactions in personal accounts, add those to your Heard books now How to add business transactions charged to a personal card
Collect and upload receipts for any purchases over $2,500
Go to Taxes > Quarterly to complete the checklist for the Q4 estimate due January 15th, 2026.

2. Deduction Documentation Cleanup

Complete your Accountable Plan by using Heard’s Accountable Plan Template Creating an Accountable Plan
Complete your mileage log: Costs incurred for using a personal vehicle for business-related travel. The reimbursement is based on the IRS standard mileage rate, which is updated annually. It is recommended to keep track of mileage using mileage logs. Accountable Plan Expense Categories at Heard

3. Payroll

You’ll see various requests on your Gusto admin Home page to review and update tax-related info. Click the to-do item to learn more about the task, then mark it as complete after you're done. You can also mark it as complete if you no longer feel the task applies.

Confirm your annual Review and correct year-to-date W-2s as needed: This task is needed to ensure all employee information is accurate before W-2s are finalized. Sign in to Gusto
- November 20, 2025: Draft W‑2s and 1099s become available. For more dates, please see Gusto End-of-Year 2025 Payroll Deadlines
Reconcile Payroll: If you need to complete any catch-up or off-cycle payroll to ensure wages are included in the 2025 W2, ensure payroll is processed and paid out by December 31st.
- December 24, 2025: Last day to run a 4‑day payroll paid out in 2025.
- December 29, 2025: Last day to run a 2‑day payroll paid out in 2025.
Confirm all payroll reports have been successfully submitted: Sign in to Gusto>Taxes & Compliance Tab> Tax Documents. All submissions should have a Completed status.

Annual Taxes with Heard

In late December, we’ll open our 2025 Annual Tax Season. Go to Taxes>Annual to let us know about your filing needs this year.

This is where you can let us know if you need to file 1099-NECs for contractors you hired this year. You’ll need to submit a 1099-NEC to the IRS for contractors whom you paid $600+ and provide them with a copy by January 31st.

If you used a Payroll provider, such as Gusto, ensure to send out W-2 and 1099 forms by January 31st.

What tax forms will I need?

You can expect to begin receiving tax forms for the 2025 tax year in January 2026 onwards.

Decide now to create a new folder on your computer to store all the tax forms as you begin to receive them.

Or upload them directly to the Tax Questionnaire of your Heard account.

The IRS generally recommends keeping tax records (including supporting documentation like receipts, invoices, and bank statements) for a minimum of three years from the date you file your return.

S Corporation Documentation (For Form 1120-S)

Document Type	Purpose	Key Items to Supply
Financial Statements	Basis for Form 1120-S	Finalized Balance Sheet (as of December 31st) Finalized Profit & Loss Statement General Ledger
Payroll Records	Proof of owner/employee compensation	Form W-2 for all shareholder employees Quarterly Form 941s or Annual Form 944
Shareholder Basis	Documentation for loss deduction limits	Prior year K-1 Records of capital contributions and distributions made during the year
Asset Records	Information for depreciation	Invoices for any major asset purchases (>$2,500)
Contractor Payments	Proof of non-employee compensation	Copies of all Form 1099-NECs issued by the S-Corp

Personal and Joint Filing Documentation (For Form 1040)

Identity documents for you and all individuals on the return
Income forms: W-2s, 1099s
Deductions and credits
Taxes paid receipts
Mortgage and property tax records

Document Type	Purpose	Key Items to Supply
Identity and Prior Year	Foundational information for the current filing.	Copies of last year's Federal and State tax returns Social Security Numbers (SSN) and birth dates for all individuals on the return (your information, spouse, dependents)
Wages and Non-Business Income	Income received by you or your spouse from employers or investments	W-2 forms 1099-INT, 1099-DIV, 10990-B (interest, dividends, investment sales) 1099-R (retirement distributions) SSA-1099 (Social Security benefits) 1009-G (unemployment compensation, state tax refunds) Rental property income and expense records
Deductions and Credits	Records used to calculate itemzied deductions or claim credits	Health Insurance: Form 1095-A, B, or C (if applicable) Retirement: Contiributions to IRAs, SEP IRAs, Solo 401(k)s Education: Form 1098-T (tuition payments) and other education related expenses Childcare: Statement of amounts paid to providers and their tax ID/SSN Charitable contribution receipts
Taxes Paid	Proof of taxes already remitted	Records of Quarterly Estimated Tax Payments (receipts) State and local income taxes paid during the year
Morgage/Housing	To claim deductions for homeownership	Form 1098 Morgage Interest Statement Property tax records