South Africans living abroad now have to pay tax on anything above their first R1.25m made outside the country.
The rest of their earnings - including all fringe benefits, like housing, education and flight allowances - will now be taxed according to the normal tax tables for the year, which can go up to 45% in some cases.
Amendments to South Africa's tax law came into effect on March 1, which means expat tax kicked in. The original plan called for a limit of R1m (£50,000).
The amendments have serious implications"
The expat tax will affect South African tax residents who are outside the country for longer than 183 days during any 12-month period and a continuous minimum of over 60 days.
South Africans living in countries with no tax treaties with South Africa can claim from the South African Revenue Service where there has been double tax. However, for South Africans living with countries with no income tax, like the UAE, the expat tax will be a hefty blow.
William Louw, professional tax practitioner with Sable International, told news outlet iol.co.za expats need to check their tax status, as the amendment specifically applies to South African tax residents - in simple terms, people working abroad, but who, in other respects, are still based in South Africa.
"The amendments have serious implications. The SA Revenue Service (Sars) considers your total remuneration, not just your salary, which means South African tax residents working in certain foreign countries and receiving additional benefits, such as accommodation and transport, could be taxed on the total value of the package."
National Treasury said defaulters may have to pay a 200% penalty.