The Auckland Ratepayers' Alliance claims switching to a public transport National Ticketing Solution will cost Auckland ratepayers at least $237.2 million.
Auckland Transport signed up to the system back in October, which will see the AT HOP Card replaced with a national card, as well as other added payment methods.
Using figures obtained under the Official Information Act, the alliance estimates the IT upgrade will cost Aucklanders $136.9-million, with ongoing costs of $100.3 over the next decade.
Spokesperson Josh Van Veen says the system is an unnecessary expenditure at a time when ratepayers can least afford it.
LISTEN ABOVE

Murray Olds: Australia Correspondent talks ISIS brides and neo-Nazis heckling at ANZAC ceremony
08:20

Angela Deken: Christchurch Hospital Newborn Hearing Screening co-ordinator on new innovation to stop babies waking during checks
03:43

Elouise Eftos: Comedian on self-deprecation, feminism, and NZ Comedy Festival
11:50