Johannesburg officials have apologised to Nelson Mandela after he was sent a warning that his water and electricity could be cut off over an unpaid bill.
They said the notice demanding payment of 6,468.48 rand ($660) should have been sent to a different house.
City officials have faced a barrage of complaints over bungled utility bills affecting thousands of residents.
South Africa's revered former president has been in hospital since 8 June with a recurring lung infection.
"The city wants to convey an apology to the Mandela family for any inconvenience caused by this unfortunate incident," the City of Johannesburg said in a statement.
The notice threatened "discontinuation or restriction of services" and legal action if the 30-day debt was not paid, local media reported.
However, city spokesman Kgamanyane Maphologela explained that the address and account number on the notice "belonged to another customer and property in a neighbouring suburb, not to the Mandela residence".
The street number and name are the same, just in a different area. Mr Maphologela said "necessary steps" would be taken against those behind the mistake.
The Mandela family home, which is situated in the wealthy suburb of Houghton, is frequently visited by well-wishers leaving messages for a speedy recovery outside the residence.
Last month, the headquarters of the African National Congress party reportedly received an erroneous bill for over 3.5 million rand.
South Africa's first democratically elected leader, Mr Mandela is considered the father of the nation. The 95-year-old spent 27 years in prison after taking up arms to fight apartheid.
Known by his clan name Madiba, he became South Africa's president in 1994 after white minority rule ended and stepped down five years later.