Thousands of Queenslanders are missing out on social housing because the government is failing to build enough homes, keep an accurate waiting list and manage existing stock, a report says.
There are 30,922 households on the state's housing register, which has grown by 78 per cent since 2018.
Auditor-General Brendan Worrall says government plans to start building 6365 social and affordable homes by 2025 is unlikely to cut the waiting list.
He says 19,025 households on the list will be offered housing, but the remaining 11,897 are likely to miss out.
"These dwellings alone will not be sufficient as growth of the register is likely to accelerate with rising interest rates and a tightening rental market," Mr Worrall says in a report released on Tuesday.
The government's failure to keep an accurate and detailed housing register is compounding the problem, the report says.
About 61 per cent of people on the waiting list are in "very high need" and 39 per cent are in lower-need groups, cannot be contacted or have inactive applications.
Before 2019, applicants were categorised as either low, moderate or high need, but since then all applicants have been recorded as high need, regardless of their situation.
Some people who applied for a home after 2019 are now either uncontactable or have inactive applications.
The list is not centrally monitored and updated, so people who should not be on it may be listed above those who are in need and have been waiting for three years.
Needs aren't recorded correctly for one in five housing applicants, and half of those approved for housing have not gone through the required internal checks.
About 15 per cent of the state's 74,133 dwellings are under-occupied, meaning they have one or more vacant bedrooms.
Tenants do not have to relocate to smaller dwellings if people move out, and there is no program to help residents enter the private housing market, the report says.
The auditor-general recommends the government regularly review and update the housing register and model future demand.
He advises the department to set up a system that prioritises applicants based on their needs, and to ensure applicants are checked before housing is allocated to them.
The government should also better manage tenants' needs to ensure bedrooms are not being left vacant, Mr Worrall says.
Housing Minister Leeanne Enoch admits it's growing challenge to access housing.
"The housing system has been under incredible pressure ... this is compounded by pressure on the construction sector for both skilled trades and supplies, interstate migration, and the recent natural disasters," Ms Enoch said in a statement.
Liberal National Party leader David Crisafulli said the report showed the government was failing the state's most vulnerable people.
"There are Queenslanders who are struggling to put a roof over their head who aren't even on this list," he told reporters.
"What is most sobering about this report is not only does the government not know who needs the homes, they don't know how to build the homes and they have no plan to fix the mess they have created.
"This is one of the most damning reports you will find ... this shows we are in the midst of a housing affordability crisis."
