Customs Duties Revenue
Customs duties were the dominant source of US federal revenue until 1913 — providing 90%+ of federal income. They now provide under 2% of US federal revenue. The decline mirrors the shift to income taxes everywhere. But in many low-income countries, customs duties still provide 10-30% of total government revenue — particularly where domestic tax capacity is weak.
Key insights
Tariffs were the original federal revenue source
From 1789 to 1913, the US federal government was funded almost entirely by customs duties on imports. Income tax was constitutionally prohibited until the 16th Amendment (1913). Tariff levels were politically explosive — the Civil War's southern grievances included tariff policy. The shift to income tax enabled the modern administrative state. Other countries followed similar transitions — UK introduced permanent income tax in 1842, France in 1914.
Customs revenue remains crucial in low-income countries
Many low-income countries get 15-30% of total tax revenue from customs duties. Imports are highly visible — they pass through ports, easy to tax. Domestic tax administration is harder — informal sector, weak record-keeping, limited audit capacity. Trade liberalization in low-income countries often loses substantial revenue, which must be replaced by domestic taxes (VAT, income tax). The replacement is often incomplete.
Modern OECD customs revenue is small
OECD countries average <5% of tax revenue from customs. The economic role of customs has shifted from revenue to: (1) protecting specific industries, (2) signaling foreign-policy preferences, (3) collecting trade data. Recent US tariff increases (2018-onward) have produced revenue gains ($60-80B/year) but the broader fiscal contribution remains small relative to income/payroll/sales taxes.
US customs duties share of federal revenue 1790–2024
% of total federal revenue
Key Finding: Dominated revenue from 1790 to 1913. Now under 2%.
Customs duties as % of tax revenue — selected countries (2023)
Customs and import duties / total tax revenue
Key Finding: Many sub-Saharan and small-island states rely heavily on customs revenue.
Methodology & caveats
Customs duty types
Import duties: the main category, on imported goods. Export duties: rare in modern economies but used by some commodity exporters (Argentina, Russia historically). Excise duties: on specific products (alcohol, tobacco, fuel) — sometimes included with customs in cross-country comparisons. Cross-country totals depend on which is included.
Why declining customs is inevitable for development
Three dynamics drive customs decline as countries develop: (1) trade liberalization reduces tariff rates; (2) domestic tax administration improves, capturing larger share of activity; (3) economic structure shifts from import-dependent to domestic production. The path from customs-heavy to income/VAT-heavy revenue structures is highly correlated with per-capita income.
Modern revenue gain from tariff increases
Recent US tariff increases on Chinese imports added ~$60-80B/year to customs revenue. But: tariff incidence falls partly on US importers (and consumers via higher prices), partly on foreign exporters. Revenue 'gained' is partly offset by economic costs. The total welfare impact of tariffs is generally negative, even if government revenue rises modestly.