Economic and technological developments have been great for offshore tax havens: Overnight mail has largely replaced wire transfers, prosperity has given Americans more money to shelter, and the Internet has given Caribbean banks and tax-shelter companies an easy marketing tool.

But credit card companies have suddenly found themselves caught up in these trends. As federal officials try to crack down on the companies that encourage U.S. citizens to shield assets from income tax, they say the easiest paper trail to follow is credit card transactions.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.