You cannot renounce something you have already lost automatically on the date of your British citizenship ceremony, if you did not apply to SA Home Affairs for permission to obtain a second nationality.
What 'letter' are you talking about??
I cannot recall if any form was required, presumably it was and I can't remember the form number. However note that you have to submit your original passport and ID book and I recall taking my birth certificate too as proof of my birth etc. You also need to take your original naturalisation certificate and your British passport. Your SA passport and ID book will be clipped and cancelled. You cannot send copies.
Presumably the letter stating you can travel in and out of SA on your British passport. This is issued free of charge while you wait in London at the Consular Home Affairs.
The letter is as follows (at least the one I got while I waited) :
CR001 wrote: ↑Fri Oct 04, 2019 9:28 am
Dear Madam,
ACQUISITION OF BRITISH CITIZENSHIP: FIRST NAME MIDDLE NAME LAST NAME
IDENTITY NUMBER: YYMMDD 0000 086
With reference to your recent enquiry, it is noted that you formally acquired British citizenship by naturalisation at the Home Office, London on
11 MONTH 2012 whilst resident outside South Africa.
Such naturalisation/registration is construed as a '
voluntary and formal act' which in terms of Section 6(1)(a) of the South African Citizenship Act (Act No 88 of 1995), resulted in the automatic loss of your South African Citizenship with consequent ineligibility for further South African passport facilities from the date of naturalisation/registration.
In terms of Section 13(3)(a)(i) of the said Act, you may only apply for the resumption of your South African Citizenship upon returning to the Republic for a continuous period of 12 months.
As you were born in South Africa, you automatically retain your right of residence. This letter, together with a valid British passport, should be produced to a Passport Control Officer at the South African port of entry to facilitate your admission.
Yours faithfully,
Pp. COUNSELLOR
IMMIGRATION & CIVIC AFFAIRS
The second letter I got later on is below :
CR001 wrote: ↑Fri Oct 04, 2019 9:29 am
Dear Mrs SURNAME
LOSS OF SOUTH AFRICAN CITIZENSHIP
This serves to inform you that your non-citizenship status has been recorded by South African Home Affairs.
Your new Identity Number is: DDMMYY 0000 185
You ceased to be a South African citizen on the 11.XX.2012 when you acquired British Citizenship by naturalisation.
It is advisable that you apply for a non-citizen identity document from this office, at your earliest convenience.
This letter must be produced when you apply for your new ID Book.
Information on how to apply for an ID Book is available on our website.
https://southafricahouseuk.com/passport ... idboo.html
Yours faithfully,
Counsellor
Immigration & Civic Affairs