Tariffs are only generating 25% of the revenue needed to pay interest on national debt—despite pitch that it would be a silver bullet

When President Trump announced his plans for a new tariff regime, he said the action was “primarily to pay down debt, which will happen in very large quantity.” But fast forward a little under a year, and the revenues generated by customs duties aren’t enough to make a dent in interest payments on national debt—let alone the headline figure.As of June 2026, U.S. national debt stands at $39.2 trillion according to Treasury data. That figure is growing by eye-watering sums: For the first eight months of fiscal year 2026, the Congressional Budget Office (CBO) reports the federal budget deficit has totaled $1.2 trillion.In its monthly budget review published last week, the CBO also broke down the government’s incomings versus its outgoings. For the first eight months of the fiscal year (which ends in September), the government raked in $3.66 trillion but spent $4.9 trillion. Income rose quicker than spending, the CBO reported, with revenues increasing by $174 billion while spending crept up $57 billion. However, income would need to rise significantly to have any impact on the value of interest payments the Treasury is paying to maintain debt levels. The CBO reported that between October and May 2026, the government has spent $742 billion servicing the debt burden, an increase on the $674 billion spent in the same period last year. The 10% increase, the CBO explained, is “because the debt was larger than it was in the first eight months of fiscal year 2025 and because of higher long-term interest rates. Declines in short-term rates partially mitigated the overall rise in interest payments.” Comparing these interest payments to income, the CBO reports that so far this fiscal year, tariffs have generated $189 billion, a little over a quarter of the payments required merely to service the debt. That said, the tariff regime suffered some setbacks, which means revenues may have come in under initial expectations: In February this year, the U.S.