Effective September 12, 2014, the State Department is adjusting the processing fees for certain nonimmigrant and immigrant visa applications, special visa services, and certain citizenship services fees; most dramatically, the fee for renouncing US citizenship is increasing significantly from $450 to $2,350. The reason for these changes, as the US Embassy in London explains, is to reflect the true cost of providing the service:

The Fiscal Year 2012 Cost of Service Model update reflected that documenting a U.S. citizen’s renunciation of citizenship is extremely costly, requiring U.S. consular officers overseas to spend substantial amounts of time to accept, process, and adjudicate cases. For example, consular officers must confirm that the potential renunciant fully understands and intends the consequences of renunciation, including losing the right to reside in the United States without documentation as an alien. This fee was first introduced in 2010 and was initially set below true cost.

Many are pointing out the huge increase in the renunciation fee coincides with the record number of Americans living abroad who are renouncing their citizenship and a five-year campaign by the Internal Revenue Service to track down tax evasion by Americans hiding money overseas, which has led to "increasingly onerous tax-filing requirements" for "many middle-income Americans living abroad who pay taxes in their host country and say they weren’t trying to dodge U.S. taxes."

On the upside: the fee for E-1, E-2, and E-3 visa applicants is decreasing from $270 to $205.