When dialed from another country, the '0' is omitted and replaced with the appropriate international access code and the country code 27.
Numbers were initially allocated when South Africa had four provinces, meaning that ranges are now split across the current nine provinces.
South-West Africa (including Walvis Bay) was integrated into the South African numbering plan.
Following its independence as Namibia, direct dialling from South Africa was discontinued and replaced by international dialling with the 264 country code.
South Africa has switched to a closed numbering system.