The government will soon decide what controls will apply in what areas under the new traffic light system, but it is still unclear if they will be applied to DHB boundaries, regions or territories.
Vaccination rates have to date been reported at a district health board (DHB) level.
However, some DHBs cover large sprawling areas - such as Southern DHB, which accounts for a quarter of the country geographically but less than 7 percent of the population - while others cover very small areas and populations, such as South Canterbury.
In response to questions by RNZ, a Covid-19 Group spokesperson said the Covid-19 Protection Framework - also known as the traffic light system - would likely apply to regional areas.
"While vaccination rates have mostly been reported by DHB, the framework is likely to be applied across regions or on a sub-regional basis, in the same way as the current alert level system," the spokesperson said.
"For example, just as parts of Waikato moved to alert level 3 recently, it is possible in future that parts of a region may be at different levels of the framework, or have localised restrictions in place.
"Decisions on New Zealand's move into the framework will be made by Cabinet on Monday, and announced after that meeting."
When asked about this, Deputy Prime Minister Grant Robertson told media there would be more detail on Monday.
"So we'll have more to say about that on Monday," he said.
"Obviously the process we've gone through up to now is we've used the DHBs as benchmarks. Clearly those DHBs are very large areas and so we are going to take some advice on what the best way of doing that going forward from here is.
"But I think when we make our announcement on Monday people will be able to see how the DHBs translate to the announcements we make."
Territorial authority vaccination rates
Regional council vaccination rates
The traffic light system would come into effect on Friday.
The government initially said every DHB would have to have 90 percent of its population fully vaccinated before moving into the traffic light system, though a carve-out existed for the three Auckland DHBs and potentially the South Island.
But that was scrapped as it became clear some DHBs would not reach the target this year and implementing the targeted controls sooner would have greater effect in encouraging vaccination rates.
However, a stumbling block to regional controls still existed.
RNZ asked the Ministry of Health whether information on vaccination rates were held at a regional level and was told: "We do not have this information at regional council level".
While vaccination rates at a territorial authority level were available, many territorial authorities were divided by regional borders.
Some, such as Queenstown Lakes Mayor Jim Boult, had already called for the controls to be applied at a local level.
The government had signalled Auckland would likely be entering the traffic light system at red, the strictest controls, despite being one of the most vaccinated regions in the country.
While community spread of cases in Auckland would be another factor in imposing the strictest controls, it did raise the spectre of whether any areas would enter the system at orange as green had already been ruled out.
The most vaccinated region in the country - Otago - still sat shy of 90 percent as of midnight Tuesday.
While only three territorial authorities - Queenstown Lakes, Selwyn and Wellington City - had passed the 90 percent double dosed mark.