Onslow iron ore exporter Mineral Resources is locked in a rates row with the Shire of Ashburton over improvements to land held under Mining Act agreements.
In a likely test case for recently-clarified rates exemptions for mining infrastructure, MinRes is challenging four rates notices in the State Administrative Tribunal.
The location of the properties and the size of the rate notices were not identified when the dispute went before the tribunal on Friday morning.
State Administrative Tribunal senior member Stephen Willey revealed the case could be important and needed careful management.
State Parliament late last year clarified rates exemptions for improvements to land held under Mining Act miscellaneous licences.
This was to deal with uncertainties created by the WA Supreme Court's ruling in July 2025 that Shire of Mount Magnet could levy rates on Vanadium Australia's infrastructure.
After hearing the conflicting views about the issues and facts in the MinRes versus Shire of Ashburton case on Friday, Dr Willey told the parties to spend a week working out what they could agree upon and what was in dispute.
"Obviously there is a lot riding on this, particularly after Atlantic Vanadium," he said.
"We don't want to get it wrong from the start.
"You're not at one on this. You have understood one state of affairs and that has resulted in decisions being made."
During legal argument earlier, Shire of Ashburton lawyer Adam Watts suggested MinRes had one or more buildings on adjoining land held under miscellaneous and exploration licences.
Mr Watts said the shire accepted that miscellaneous licences were not ratable.
"The shire's position is that rates only relate to exploration licences," he said.
Without identifying the location, Mr Watts referred to one notice "relating to only a capital improvement on the camp".
He said the shire needed more time to consider it position.
MinRes lawyer Lauren Shave said her client was "very keen to move the matter on" given it had been grappling with the issue since April last year.
"It's a question of whether the rates that have been imposed are on miscellaneous licences, which are not ratable," she said.
The parties return to the tribunal on August 14.
MinRes declined to comment or identify the location of the properties.
