The Story

2005

R.T. Rawlings (lead, first-listed), Brian Hilst, Simon Blackwell, and Mark Withers — four named inventors — filed U.S. Patent Application US20070136158A1, “Accurate tax calculation,” claiming priority to U.S. Provisional 60/749,529 filed December 12, 2005. The application was filed under the company's original corporate name printed on the application as “Advantage Solutions, Inc. / DBA Avalara, Inc.”

The application was abandoned — not on the merits. Faced with the choice between paying the patent attorney and making payroll, he made payroll. The patent lapsed; the invention didn't. As accurate as the 20-year-old technology would allow, its architecture became AvaTax — the flagship of a company later acquired for approximately $8.4 billion.

2026

The same person files U.S. Provisional 64/097,002 — the patent-pending successor: SALTklaw. Its consistent classification subsystem turns the non-deterministic classifications an LLM produces from synonyms and broad categories into a single deterministic answer — the same statute, read the same way, every time. It finally does what the 2005 filing could not: accurately calculate and file sales taxes. So accurate that SALTklaw offers a first-of-its-kind guarantee.

Deterministic Statute-Bound Tax Determination with Cadastral Situs Resolution

Patent Pending — U.S. 64/097,002

I designed the original jurisdiction assignment. I named it “rooftop.” It was never rooftop — it's a centroid, a guess, and I know because I built it. I wrote the taxability codes Avalara still ships, and every code is a guess dressed as an answer. Accuracy was never one thing. It is the intersection of three: the product bound to its statute, the sale resolved to the actual parcel, and a self-audit that checks both against the law. Where those three meet, no doubt about accuracy survives. That intersection is SALTklaw.

— R.T. Rawlings, inventor of SALTklaw and AvaTax

No audit finding, or your money back

We are certain enough to put money on it. If an administering jurisdiction — typically the state — audits you and issues an official finding that sales tax SALTklaw calculated was under-reported or mis-calculated, we refund 100% of the SALTklaw service fees you paid for the period of the discrepancy. To be precise: the only money you ever pay us is our service fee. The tax you remit sits in a trust account we file from and is never ours — so the guarantee returns our fees, in full, not your tax. No cap at a small multiple; no fine print that makes it worthless.

We can offer this because the method is deterministic: the product is bound to its statute, the situs is the actual parcel, and the self-audit checks both before you ever file. When your return already reaches the same answer the state would, an adverse finding is our failure — so we cover it.

No one else in this industry does this. The enterprise incumbents offer no money-back guarantee at all — you keep the liability. The few that do cap it at a small multiple of your fees. We cover the period, in full.