Watch Peter’s Tax Walkthrough
Peter (Tiller’s founder and a daily Tiller user) recorded a short masterclass on his actual tax workflow, including the sheet he shares with his accountant.
Using Google Sheets?
Using Excel?
Step 1 — Get Your Transactions Categorized
Tax prep is fastest when your transactions are already categorized. Pick the option that matches where you are.
Already categorized throughout the year? Skip to Step 2. You’re ready.
Behind on categories?
Don’t go back and organize all of 2025. Sort your Transactions sheet by Description: you’ll see every Amazon charge, every doctor visit, every Costco run grouped together. Find the tax-relevant ones, categorize those, and leave the rest alone.
If you have a large backlog and want to move faster, AutoCat can apply rules automatically: every charge from a specific merchant gets categorized without touching each row individually.
Really behind and starting from scratch? Reach out to beta@tillerhq.com about the pre-categorize workflow.
Step 2 — Filter to Your Tax-Deductible Expenses
Once your relevant transactions are categorized, filtering takes about two minutes.
- Click the dropdown arrow in the Category column header in your Transactions sheet
- Click “Clear” to deselect all categories
- Check only the tax-deductible categories you want to review:
- Medical
- Donations
- Mortgage Interest
- State & Local Taxes
- (Add any other categories that apply to your tax situation)
- Click OK
- Select all visible rows, copy, and paste into a new sheet Important: Make sure you’re copying only the visible (filtered) rows, not all rows in your sheet.
- Name it “2025 Tax Deductions”
Google Sheets users: enable filtering first by clicking the filter icon in the toolbar. Excel users: filtering is on by default.
Learn more about filtering in Google Sheets |Excel
Step 3 — Share With Your Accountant (or File Yourself)
Export your new deductions sheet as a PDF or share the Google Sheet directly. Accountants appreciate the format; it’s easy to edit, easy to sum, and everything is labeled.
Want a more polished report?
The Category Rollup Report generates formatted subtotals by category in one click. Tag your tax-deductible categories as “Tax” in your Categories sheet, run the report, and you have a clean summary ready to hand off. (Requires the free Tiller Community Solutions add-on.)
For a quick visual of all spending by category, a yearly pivot table works well too.
For Self-Employed Filers and Quarterly Taxes
If you’re self-employed, freelancing, or paying estimated quarterly taxes, Tiller has dedicated tools for that.
→ Spreadsheet for estimating quarterly taxes
→ 95 IRS business expense categories
Access to the Estimated Quarterly Tax sheet is provided as a convenience to help you estimate your state and federal quarterly taxes for the tax year indicated. Its use for any other purpose, including the calculation and preparation of income tax forms for filing with the IRS, is beyond the scope of this tool. Tiller makes no guarantee in regard to the accuracy of the calculations, tax rates, or results. Consult a tax advisor or accountant to validate the accuracy of the results.
Still Have Questions About Using Tiller for Taxes?
Join the conversation in the Tiller Community. Our members share tax workflows, answer questions, and help each other navigate tax season every year.
Need hands-on help? Our support team is here for you.
Ready to Make Tax Season Easier?
With Tiller, your financial data is automatically organized all year long, so when tax season rolls around, you’re already prepared.
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