The entire $51.3 million raised by comedian Celeste Barber in response to last summer's devastating bushfires must go to the NSW Rural Fire Service (RFS) and Brigades Donation Fund, the NSW Supreme Court has ruled.
The court ruling means none of the donations can be distributed to other charities or states to directly support victims of the bushfires.
However, the money can be spent to support rural firefighters injured while fighting blazes or the families of firies who died.
Barber in January prompted an outpouring of goodwill and donations from across the world when she launched the "Please help anyway you can. This is terrifying" appeal on Facebook.
She nominated the NSW RFS as the beneficiary of the campaign and set a funding target of $30,000.
But Barber - who boasts 7.1 million followers on Instagram - raised $51.3 million, which is the largest charity drive in Facebook's history.
Hours after the ruling, the comedian posted a statement to social media, saying while the money would be in the "very capable, very grateful hands of the NSW RFS", she had "hoped" it could have been shared more widely.
"I had hoped, because it was such a big and ‘unprecedented’ amount, that it could have been distributed to other states and charities [but it] turns out that studying acting at university does not make me a lawmaker,” the statement read.
The NSW RFS had gone to the NSW Supreme Court seeking clarity on the use of the money according to its April 2012 trust deed.
Justice Michael Slattery answered their four questions and ordered the parties' legal costs to be paid out of the RFS Fund.
NSW RFS spokesman Greg Allan says the service accepts the ruling and appreciates the support from Barber and the wider community.
"With this direction, we can uphold what the trust was set up for in the first place, and that is supporting the volunteer members and their communities," he told AAP on Monday.
The RFS has sought feedback from members regarding how the funds should be spent.
The cash will likely be used to purchase fire fighting equipment including respiratory systems, helmets and tools such as chainsaws. It will also help improve "network connectivity" in vehicles and upgrade local stations.
Additional reporting by AAP.
