What happens to Texas companies that sell nationwide?

They keep selling nationwide, because their customers are still there and the goods still cross on tariff-free terms. Companies export across borders every hour of every day. A Texas business selling into the other 49 states would simply be exporting, the same way it can already export to 200 countries.

Selling across a border is the most ordinary thing in commerce

The fear is that a Texas company loses its national market the moment a border exists between Texas and the rest of the union. But selling across a border is not exotic. It is what trade is. A Texas company already sells to customers in Mexico, Canada, Europe, and Asia without those customers being fellow Americans. Adding the other 49 states to the list of places Texas exports to does not shrink the market. The customers in Dallas-bound trucks headed to Oklahoma or Louisiana are the same customers the day after independence as the day before.

Tariff-free access is the whole design of the plan

The reason this stays smooth is that keeping trade free is the entire objective. A negotiated free-trade arrangement or customs union with the United States, which is in Washington's interest too, keeps goods moving between Texas and the other states with no tariff and no new cost. The live answer on trade with the United States lays out exactly how that works, including the fallback of trading under existing World Trade Organization schedules if the two sides take their time. Under any of those paths, a Texas company's product reaches a customer in Ohio on the same commercial terms it does now.

The product is bought because it is wanted, not because of a flag

A customer in another state buys a Texas product because of price, quality, and availability, not because Texas and that state share a federal government. Texas chemicals, Texas-refined fuel, Texas food, and Texas-made goods are bought because buyers want them. None of that demand is created by political union, so none of it disappears when the union does. The seller still has the product the buyer needs, which is the only thing that ever drove the sale.

The cost side gets better, not worse

Independence does not just preserve the national market. It improves the company selling into it. By TNM's analysis, the federal regulatory layer costs Texas manufacturers an estimated $30 to $50 billion a year in compliance overhead. Shedding that layer lowers the cost of producing the goods that Texas companies sell everywhere, which makes them more competitive in the national market, not less. Lower compliance cost plus a preserved no-income-tax structure is a tailwind for a Texas exporter, not a headwind.

The bottom line

A Texas company that sells nationwide keeps selling nationwide. Its customers do not move, tariff-free access is the point of the plan, and its cost of doing business goes down when the federal regulatory layer comes off. Selling across the new line is just exporting, and exporting is what Texas already does better than any other state.