But the warning nevertheless surprised economists and traders, many of which had been forecasting the first rate hike to come in the spring of next year. With the economy strengthening and the unemployment rate dropping to 6.6 percent in the three months ending in April, the pressure to raise rates sooner has increased.
Economists quickly updated their forecasts, with some predicting a rate hike by early 2015, or even sooner.
"We acknowledge that this forecast change is being made against the metaphorical cacophony of stable doors being slammed shut," said Ross Walker of RBS U.K. economics. "Perhaps we ought to have seen it coming."
Walker, however, pointed out that the abrupt moves in the pound and fixed income markets show that the investors did not in fact see it coming.
Carney's first year in office has been defined by a "forward guidance policy," which kept rates low and closely tied an interest rate rise to a drop in unemployment.
But as economy the strengthened, and unemployment fell below the level where a rate rise would have been considered, "forward guidance" passed into history. In need of a way to tell the British public that change was near at hand, Carney chose a big forum to send a strong hint that rates could rise soon.
Should a rate rise happen this year, Britain would be way ahead of the ECB, which is still cutting rates — and maybe even ahead of the U.S. Federal Reserve, said Stephen Lewis, chief economist of Monument Securities.
"The markets have, for a while, suspected the BoE might be the first of these central banks to tighten," Lewis said. "Mr. Carney's comment has served to strengthen their conviction."