With the U.K.'s recent move to clamp down on bank bonuses sparking rumors of a financial decampment from London, countries with lower tax rates like Switzerland and Monaco are aggressively competing to lure multinational businesses to establish headquarters in their cities.

The one-time 50% tax on all discretionary bonuses over £25,000 ($39,960) in the U.K. has given hedge-fund managers and investment bankers added incentive to start moving to more tax-friendly states.