Tiller or AI Financial Guidance? Keep the Work That Matters

Updated September 26, 2026.

You do not need to “graduate” from a spreadsheet merely because you have more accounts. Keep Tiller if your spreadsheet gives you a useful, maintainable financial routine. Evaluate an advice workflow when the missing job is interpreting a decision rather than organizing the data.

Tiller's appeal is control over a spreadsheet-based financial system with connected information. That can be a strength for someone who wants custom reports and transparent calculations. It is not evidence that the user is behind the times. Tiller overview

Ask which work is becoming difficult

A spreadsheet can be doing several jobs at once: storing transactions, categorizing spending, calculating net worth and supporting a financial decision. Trouble in one area does not require replacing every part.

There is no universal account-count or hours-per-month threshold that proves a spreadsheet has stopped working. Judge the consequences: errors, delayed decisions, missing information or a routine no one can maintain.

What Tiller still does well

A spreadsheet lets you inspect formulas, organize categories and build a report around your own question. For some households, that transparency is the reason to keep it. The ability to modify a calculation also creates responsibility to verify it.

Tiller announced a price change from $79 to $99 annually effective August 1, 2026, with renewal timing described in its announcement. Check your own renewal rather than using an older price in the comparison. Tiller pricing announcement

At $99, the question remains whether the system performs useful recurring work. A more expensive application does not automatically replace the customization or historical records you built.

Where Mezzi adds a different capability

Mezzi connects supported Investments, Banking, Other Assets and Liabilities. AI Personalization records goals and preferences that a transaction feed cannot infer reliably. Exposure X-Ray helps investigate underlying exposure in supported funds. Mezzi account groups

A useful question might be: “What should I verify before deciding whether new savings can fund this goal?” The answer should connect the available financial picture with your reserve, debts, timing and missing information.

That conversation does not make Mezzi a replacement for every custom formula, spreadsheet import or tax record. It also does not implement trades. You should retain any specialist record system the decision still needs.

A practical example: preserve the calculation, add the context

Suppose a spreadsheet correctly shows $20,000 of cash. The household has a $7,000 upcoming expense and intends to retain a $10,000 reserve. Under those illustrative assumptions, $3,000 remains uncommitted.

The arithmetic is simple. The more useful discussion is whether the assumptions are complete: other liabilities, timing of income and competing goals. A spreadsheet can hold those inputs, while an advice workflow can help question them. Neither should treat the full $20,000 as automatically available to invest.

Use the same example in a trial. Ask the assistant to show the calculation and identify missing inputs. Then check it. An AI answer should not receive less scrutiny than a spreadsheet formula merely because it is written confidently.

Choose between replacing and supplementing

Keep Tiller if the custom records are useful and the maintenance is reasonable. Add Mezzi if you want a recurring financial conversation that your current system does not supply. Replace the spreadsheet only if the new arrangement covers the work you intend to retire.

Mezzi Advisory is $399 annually and Concierge is $999, with Free available. Keeping a $99 Tiller subscription and adding Advisory creates $498 of annual software spending at unchanged prices. That is a combined arrangement, not a $300 saving. Mezzi plans

Compare that cost with the actual work performed. Do not assign a dollar value to assumed tax savings or returns that have not occurred.

Preserve and test your records

Keep original transaction data and important formulas before changing anything. Document account names, category definitions and the dates covered. A file that another tool can read may still lose the logic behind a custom report.

Test a representative period with transfers, irregular expenses and any manual assets. Check whether totals agree after accounting for date differences. If the candidate cannot reproduce a report you need, decide whether to keep the spreadsheet for that job.

If you share financial information with an AI tool, review its permissions and data terms. Use only the records needed for the task and keep private financial data out of public examples.

Give the spreadsheet and the conversation different jobs

Consider a spreadsheet that projects six monthly expenses of $4,000 from a $30,000 cash balance. With no additional inflows, the worksheet shows $6,000 remaining after $24,000 of expenses. That is a reproducible calculation worth preserving, especially if it is part of the household's established planning process.

An advice conversation can ask a different question: does the expense list omit an annual insurance bill, a tax payment or a reserve the household wants to keep? If a $3,000 bill and $5,000 reserve were missing, the modeled $6,000 remainder would be $2,000 short of those additional commitments.

These invented inputs illustrate why a spreadsheet need not be abandoned to benefit from contextual guidance. Keep the original formulas and verify calculations independently. A fluent AI answer is not a replacement for a well-maintained model, and a correct formula does not prove every relevant assumption was entered. Use Mezzi only if the connected context and discussion improve the question you are trying to answer.

Make the system easier to maintain

The ideal outcome is a routine you can explain and repeat. That may be a better spreadsheet, a connected advice workflow or both. Change the tool when it improves the financial work, not because a larger portfolio supposedly disqualifies a familiar method.

For other analytical approaches, see portfolio analyzers compared.

Frequently asked questions

Does a large portfolio mean I should stop using Tiller?

No. Evaluate whether the spreadsheet remains accurate, understandable and maintainable. Account size alone does not determine the right workflow.

What is Tiller’s current annual price?

Tiller announced $99 annually effective August 1, 2026, with renewal timing described in its announcement. Check your subscription terms.

Can Mezzi replace every spreadsheet calculation?

Do not assume that. Test the reports and records you need, and retain specialized calculations where appropriate.

Can I use both?

Yes. A spreadsheet and a guidance workflow can perform distinct jobs. Include both costs and verify that each earns its place.