The current account gap has traditionally been partly financed by portfolio inflows, but these have waned this year as investors expecting the US Federal Reserve to start tightening monetary policy dumped emerging markets.
The shortfall expanded to 4.1% of GDP in the third quarter from 3.1% in the second, the South African Reserve Bank (SARB) said in its December quarterly bulletin. This is the first time in five quarters that it has widened.
Economists polled by Reuters had reached consensus on a 4percent deficit in the third quarter.
The rand, which has weakened more than 20% against the dollar this year, hit a new record low of 14.6150 after the central bank report.