
We kept the books before we wrote the code.
Tarn was founded in San Francisco in 2019 by people who had run the finances of bakeries, studios and practices from back offices and kitchen tables.
- Founded
- 2019
- Headquarters
- San Francisco
- Team
- 38 people
- Businesses forecasting
- 4,200+
It started with one spreadsheet.
For eight years Nadia Brandt ran the money side of her family’s four bakeries in Oakland. Every January the same thing happened: the holiday cash ran out faster than anyone expected, and payroll got tight in the last week of the month.
She built a weekly cash sheet to see it coming. It worked, but it took her every Sunday evening to keep it current. In 2019 she and Owen Achterberg, who had spent years building bank-data systems, set out to make that sheet keep itself up to date.
Seven years later the idea is the same. Read the real numbers every morning, show the weeks ahead, and warn the owner while there is still time to act.
Payroll week Closing balance $7,550, with $24,000 of wages due Monday.
What we believe.
Owners deserve a CFO’s view.
Large companies have a finance team watching cash every day. A fourteen-person studio has the owner, on a Sunday night. Tarn gives that owner the same weekly picture, without the team.
Weekly beats monthly.
Cash problems happen on a particular Thursday, not in a month. Every number in Tarn is weekly first, because that is where a tight spot shows up.
An honest forecast is a useful one.
We show the likely range, mark what is a guess and compare every forecast with what really happened. A forecast that always looks good is not doing its job.
Calm, read-only and private.
- Calm
- One email on Monday morning, and an alert only when something actually changes. No streaks, no badges, no daily nudges.
- Read-only
- Tarn connects to your bank through a regulated provider with read-only access. It cannot move money, and it never sees your bank login.
- Private
- Your numbers are yours. We do not sell data, show ads or train models on your accounts. Close your account and everything is deleted within 30 days.
Tarn can
- Read balances on 4 accountsDaily, 6:00 AM
- Read transactions from the last 24 monthsRead-only
- Read scheduled paymentsRead-only
Tarn can never
- Move money or make payments
- See or store your bank login
- Change anything in your bank account
The people behind the forecast.
Thirty-eight of us, in San Francisco and remote across North America. Half the team has run or kept the books for a small business.

Nadia Brandt
Co-founder and CEO
Ran the finances for her family’s four bakeries in Oakland for eight years, mostly from a spreadsheet at the kitchen table.

Owen Achterberg
Co-founder and CTO
Built bank-data pipelines at a payments company, and kept the books for his partner’s architecture practice on the side.

Priya Sethi
Head of Customer Finance
A bookkeeper for more than forty small businesses before Tarn. Runs onboarding and the walkthroughs.

Luis Romero
Head of Design
Designs the forecast so an owner can read it in under a minute. Previously at a field-service software company.
Seven years, one idea.
- 2019Founded in San Francisco
Nadia and Owen turn the bakery spreadsheet into software for twelve friends’ businesses.
- 2020The 13-week view
Built in a month as owners asked how long they could keep paying staff.
- 2021Scenarios
Test a hire, a late client or a big purchase before committing to it.
- 2022Bills and payroll
Scheduled payments and payroll runs flow in from the tools owners already use.
- 2023Eighteen months out
The forecast reaches eighteen months, and advisers get their own access.
- 2024Group plan
Several businesses and currencies in one consolidated forecast.
- 20264,200 businesses
Studios, roasteries, practices and workshops across the US and Canada.
Talk to someone who has done the books.
A 20-minute walkthrough with Priya’s team, using your own numbers if you like. No slides.