The Office for National Statistics said the consumer prices index rose by 0.1% between December and January this year - the first time ever that prices have risen between a December and January, comparing with a fall of 0.2% a year ago.
Between 1997 and 2009, the one month change between December and January has varied between falls of 0.3% and 0.9%.
Retail prices index inflation stood at 5.1% in January, up from 4.8% the previous month.
David Hollingworth, head of communications at London and Country, said: “While it could have been worse, this number is not going to dampen speculation about when base rate will increase.
“Most people seem to be putting the jump in inflation down to the hike in VAT but despite this I think this signals a gathering of momentum for the Monetary Policy Committee taking some kind of action on rates. That clearly will have an immediate knock on for mortgage borrowers.”