About

An accounting firm for the people who sign the checks.

Theorem is built for owner-operated businesses: the contractors, clinics, restaurants, and studios who carry real financial complexity without a finance team to hand it to.

Ask an owner about their accountant and you tend to hear the same story. Books that arrive months late. A tax bill that shows up as news. A question sent in October, answered in January, if at all.

That is not because accountants do not care. It is because the traditional firm bills by the hour and batches its work, so the incentives point away from being current and away from picking up the phone. The client learns not to call. The accountant learns to catch up in March. Everyone accepts it.

We started Theorem to run the same profession on a different footing. Your month closes by the tenth. Your questions get answered the same day. What you owe is tracked as the year happens, so April is arithmetic instead of a surprise. And it costs one flat fee, so picking up the phone never costs you anything.

Behind that is one accountant who knows your business and signs their name to the work. Not a rotating cast, not a ticket queue, and not someone meeting your books for the first time in March.

2026
Founded
United States
Where we serve
Owner-operated
Who we work with
What we believe

How we practice

The owner deserves an answer

You should not have to wonder what a phone call will cost, or wait a week to find out whether you can afford a hire. Being reachable is not a premium service. It is the service.

Provable beats plausible

Every number we give you traces to a source document. If we cannot show where a figure came from, we do not put it in front of you.

Current beats correct-in-April

A right answer four months late is not much use to someone deciding this week. We would rather hand you numbers you can act on now and stand behind them.

Come talk to us

A short call, a straight answer on what it would cost. No obligation.

Talk to us