What share of the federal debt would Texas have to take on?

That figure is a negotiation, not a bill, and Texas would negotiate it from real strength. By the methods international law actually recognizes, a good-faith reckoning can land at zero, because what Washington owes Texans is larger than any share it could assign. This is about the federal debt, not a "national debt," because the United States is not the nation here.

The opening demand, and why it is only an opening

Washington would open by demanding that Texas take a per-person slice of the federal debt, which on the tax-weighted measure is about $3.2 trillion. That number is not a settled liability. It is a starting position. No law sets Texas's share. The only international instrument on the subject, the 1983 Vienna Convention on succession of state debts, is barely ratified, never entered into force, and contradicts itself: one article says no debt passes at all unless both parties agree, another asks only for an unspecified "equitable proportion." There is no formula to hand down.

Even the starting percentage is a fight

The scholars who tried to build a formula could not agree on one. Texas is 8.2 percent of federal taxes paid, about 9.3 percent of the population, and about 9.5 percent of GDP, so the "share" swings by hundreds of billions before anyone argues method. Daniel Blum's standard survey in the Case Western Reserve Journal of International Law lays out four recognized methods, each called "just" by someone, each landing in a completely different place, from a per-capita demand of trillions down to as low as zero for a net contributor under the historical-benefits method. We do not rest the case on the zero result. We rest it on the methods and arguments that hold regardless.

The decisive fact: net what each side owes the other

Here is what turns the debt question over. In any separation, what each side owes the other gets netted out, and Washington owes Texans far more than it could ever invoice. The Treasury's own FY2025 financial report puts the federal government's unfunded 75-year Social Security and Medicare obligation at $88.4 trillion. Texans funded about 8.7 percent of it, an accrued claim on the order of $7.7 trillion. That is more than double the $3.2 trillion debt share. Put both claims on the table and the debt disappears into the benefits Texans are already owed. Either the checks keep flowing by agreement, which is cheaper for both sides, or Texas's benefit claims cancel the debt bill outright.

Serious scholarship and history both point low

Professor Matt Qvortrup, who studies how new countries are actually formed, concludes an independent Texas would not be liable for the federal debt. The four-century-old doctrine of odious debt recognizes a category for debt "incurred to suppress secessionist movements," and decolonizing nations walked away from colonial debts on exactly that principle. History is a muddle that cuts toward Texas: the United States took on none of Britain's debt in 1783, Norway took none of Sweden's in 1905, and South Sudan started debt-free in 2011 because Sudan kept all of it. There is no single rule, only a negotiation, and Texas brings energy, ports, and Washington's own overriding interest in not detonating the Treasury market during a separation.

What is not negotiable is the bill Texans pay now

While the exit figure is contested, the cost of staying is not. Texans ship about $72 billion a year to Washington just in interest on this debt, plus about $150 billion a year in fresh borrowing, on an obligation that will never be repaid in a dollar that never stops shrinking. Staying is the expensive option. Leaving puts that outflow to a stop.

The bottom line

There is no fixed share. The figure Washington would invoice is an opening demand with no law behind it, and the benefits Texans are owed, about $7.7 trillion, more than cover any share that could be assigned. A good-faith reckoning by recognized methods can land at zero, while the cost of staying runs to the hundreds of billions a year.