The UK's current account deficit soared to an all-time high of £31.9bn ($55.3bn) in 2005, reawakening concerns about the health of the economy.
More goods were imported than exported last year
A decline in trade in both goods and services was behind the gap, the Office for National Statistics said.
The gap is equal to 2.6% of GDP, much higher than the £23.6bn reported in 2004 and is the worst since records began at the end of World War II.
Economists expected the pound to weaken over the coming years as a result.
Simon Wallace, of the Centre for Economics and Business Research (CEBR), said the figures "demonstrate that the UK economy is not in a healthy state".
"Although exports of services had increased over the year, they could not keep up with the increasing demand for service imports," he said.
The final quarter of last year was the worst period for trade imbalances.
Goods and services worth £11bn were brought into the UK, much more than the £4bn forecast by economists.