Martens Law

Focus and practice areas

Based in Austin, the firm concentrates on Texas state tax matters. It represents businesses in sales tax audits and franchise tax audits. The firm also handles tax refund claims and carries disputes through administrative hearings, trials, and appeals.

That focus is narrow by design. Tax controversy work rewards depth, and the firm keeps its whole caseload inside Texas state tax. In my opinion, that kind of concentration is worth more to a business than a long menu of loosely related services. It signals where the firm has chosen to build its experience.

The taxes the firm handles

Texas collects several taxes beyond the familiar sales tax, and Martens Law works across a wide slice of them. The firm handles Texas sales and use tax and the franchise (margin) tax. It also takes on motor vehicle and motor fuels taxes, oil and gas production (severance) taxes, oil well servicing taxes, and boat and boat motor sales taxes.

Severance taxes apply when oil and gas come out of the ground, and they carry their own rules on valuation and reporting. That breadth maps onto the industries the firm names. Its clients include small businesses and Fortune 500 companies. They work in oil and gas, technology, construction, and retail. A retailer and an oil producer meet different parts of the Texas tax code, and the firm's list of tax types covers both.

Inside a Texas tax audit

Most of this work begins with an audit from the Texas Comptroller of Public Accounts. In a sales and use tax audit, the state reviews a business's records to test whether it collected and paid the right amount on taxable sales. Auditors often sample invoices and exemption certificates, then project the findings across the whole audit period.

A franchise tax audit follows a different path. The margin tax turns on how a business figures its taxable margin, including the deductions it takes for cost of goods sold or compensation. Disputes here tend to hinge on classification and arithmetic, and a business usually needs clean records to answer the state's position. Martens Law handles both audit types.

The records that decide the outcome

Texas tax disputes usually turn on documentation. In a sales tax matter, exemption and resale certificates often decide whether a transaction was taxable, and gaps in those records can drive an assessment up. A business that keeps clean invoices and contracts gives its counsel more to work with at every stage.

The Comptroller generally works from a four-year look-back period, so an audit can reach transactions a business has half forgotten. Reconstructing that history is part of the job, and it shapes how a case is argued at a hearing. This is the ground Martens Law works on, across the tax types it lists.

Hearings, refunds, and appeals

When a business contests an audit result, the case can move to the State Office of Administrative Hearings. An administrative law judge there reviews the evidence and issues a proposal for decision. A taxpayer who still disagrees can carry the matter into the Texas courts, up to the Texas Supreme Court.

Refund claims run on a separate track. A business that believes it overpaid can file to recover the money, and a denied claim can itself turn into a hearing or a suit. Each of these steps runs on statutory deadlines, and a missed date can close a route to relief. Martens Law handles the audit, the administrative hearing, the trial, and the appeal.

Some of these disputes reach an actual trial. A taxpayer can sue the Comptroller in Travis County district court, and the case then runs on courtroom rules of evidence and procedure. The firm handles this trial and appellate work too.

How the team is built

The site names three attorneys and one audit defense professional. Jimmy Martens, Gordon Martens, and Katie Bone are the attorneys. Drew Renken works as an Audit Defense Professional, a role centered on the audit stage where many of these disputes start.

Jimmy Martens holds board certification in tax law from the Texas Board of Legal Specialization. In Texas, that certification goes to attorneys who meet set experience and examination requirements in a field, and tax law is one of the areas it covers. Every attorney at the firm is licensed to practice before all Texas state courts, including the Texas Supreme Court. That court admission carries weight in tax work, because a contested assessment can end up on appeal.

What the record shows

The clearest signal here is the concentration. A firm that works on one body of law builds pattern knowledge across audits that a broad general practice will struggle to match. Martens Law puts its whole caseload into Texas state tax.

The office location fits that focus. As a reviewer, I read the board certification and the court admissions as concrete, checkable facts about the people doing the work. Martens Law keeps its office near the Texas Comptroller's office, the State Office of Administrative Hearings, and the Travis County District Courthouse. Those three bodies handle the audits, hearings, and appeals the firm works on.