The current account deficit was much higher than that of £6.2bn in the second quarter , and way ahead of a consensus City forecast of £13.85bn. It equated to 5.1% of gross domestic product.
The balance of payments figures, published yesterday by the Office for National Statistics, showed the UK's trade deficit widened to £10bn in the third quarter from £5bn in the preceding three months.
The UK's income balance moved from a £6bn surplus in the second quarter to a £3.7bn deficit in the three months to September.
The ONS noted that UK earnings on direct investment abroad decreased by £6.9bn between the second and third quarters. The deterioration in the income balance also reflected higher profits for foreign-owned UK private non-financial corporations.
Howard Archer, chief UK economist at consultancy IHS Global Insight, said: "The current account data for the third quarter of 2013 are truly dire."
Separately, the ONS yesterday confirmed its earlier estimates that UK gross domestic product had risen by 0.8% in the third quarter.
However, upward revisions to prior quarters meant GDP in the third quarter was up 1.9% on the same period of last year. The ONS had estimated previously that GDP in the three months to September was up 1.5% on the same period of 2012.