Grandparents Paul and Sue Rutherford care for their grandson, Warren, who has a rare genetic disorder.
Their case, and that of an anonymous domestic violence victim who has a panic room in her home, were both discriminatory, judges ruled on Wednesday.
Their cases are the latest examples of successful challenges to the controversial "subsidy", which penalises those with "spare" rooms.
Here is a list of some of the most high-profiled successful challenges to the government's scheme.
Ann and Kevin Gresham
Ann and Kevin Gresham, from West Yorkshire, took their case to court after their housing benefit was cut by 14%.
They won their case in August 2014 after a judge ruled that the couple shouldn't lose the money or move.
The couple lived in a two-bedroom flat in Dewsbury which had been adapted for wheelchair use due to Mrs Gresham's disability.
Mrs Gresham broke her back in a car accident in 1973.
Diagnosed as bilateral sciatica, daily spasms would leave both her legs paralysed. She needed a wheelchair, or on better days, a walking stick, to get about, The Press News reports. Her husband quit his job as a bus driver to become a full-time carer.
But under the government's new housing rules, the pair was deemed to have a surplus bedroom.
As a result, they were told to move to a one-bedroom flat or lose part of their housing benefit.
The judge said that the scope for finding a one-bedroom flat big enough for two beds and disabled equipment was "slim" and allowed the couple's appeal, the BBC reports.
Jacqueline and Jayson Carmichael
The married couple won a court case exempting them from the "bedroom tax" in April 2014, arguing they needed two rooms due to Jacqueline Carmichael's severe disability.
Mrs Carmichael, who has spina bifida, and husband Jayson won their civil case against Sefton Council, which meant they would not have to pay an extra £56 a month on their two-bedroom flat in Southport.
The couple's flat was too small to accommodate two beds, meaning that Mr Carmichael had to sleep in the other room.
A judge ruled: “The appellant is entitled to two bedrooms under the provision of the Human Rights Act and no under occupancy reduction of 14% should be made on his benefit entitlement.”
Sue Bott, the director of policy and development at charity Disability Rights, told The Huffington Post UK: "I think the bedroom tax is looking more and more ridiculous to be honest.
"Disabled people have always been allocated housing based on their need. Then the government comes along and says 'we're changing everything, your need doesn't matter anymore'."
Mr Carmichael said: “Everybody is delighted, if not a little shocked by this result. This extra money will do us the world of good.”
Alison Huggan had two sons in the Army when she was told that she would be liable to pay the spare room subsidy after being told that her children's home was their barracks.
She was told that she would be liable to pay £25 a week for her sons' rooms, despite families with adult children in the armed forces being told they would be exempt.
After taking her case against Middlesbrough Council to a tribunal, she won and was given a refund of about £700.
Unnamed, disabled woman
REGINA MARTÃNEZ VIA GETTY
A disabled woman who was unable to share a bedroom with her husband won her appeal against the so-called bedroom tax in October 2013.
The tribunal found that the local authority had "not taken into consideration her disabilities and her reasonable requirements".
The tenant, who chose to remain anonymous, suffered from various health conditions and required a wheelchair and stairlift after suffering a stroke.
Along with her husband, she had argued that due to her condition they required one bedroom each, but this was rejected by Redcar and Cleveland Borough Council who said they were under-occupying their three-bedroom house.
The council's decision was overturned.
The woman's husband said: "Getting a satisfactory outcome to our housing benefit tribunal was quite a surprise to us when you take into account what we read in the media and you see what has happened in the High Court recently.
"The tribunal concluded that although we are a couple, my wife's particular circumstances, the extent and effect of her disabling medical conditions and her resulting needs due to her disabilities, mean that we reasonably require one bedroom each and should therefore be assessed for Housing benefit on this basis."
Surinder Lall, who is blind, won an appeal against Westminster City Council in September 2013.
Barrister, Lall, argued successfully to a tribunal that a room in his flat classified as a second bedroom had never been used as one and had always been where equipment helping him to lead a normal life was kept, the Guardian reports. The judge noted: "The term 'bedroom' is nowhere defined [in the relevant regulations].
"I apply the ordinary English meaning. The room in question cannot be so defined."
Although Westminster council said it had invited Lall to apply for a discretionary payment, he did not accept the invitation.