Focus Ireland says responsibility for publishing homeless figures should be taken away from the Government.
The charity's calling for the Central Statistics Office (CSO) to take over after the Department of Housing's April figures showed a slight drop to 9,652.
But the department took around 300 people out of the figures, saying they're actually in homes and not emergency accommodation.
Roughan McNamara from Focus Ireland says confusion over the numbers needs to be cleared up.
"We need to get away from squabbling about the numbers - which this really is again this month - and have an agreed format as there was in place as to who is and isn't homeless.
"This doesn't get away from the fact we're still in a crisis".
Housing Minister Eoghan Murphy | File photo
Inner City Helping Homeless (ICHH) say while the overall figure has dropped slightly by 29 people from March, people have been removed under Minister Eoghan Murphy's reclassification project.
It says 297 people were removed by Dublin and Meath county councils - meaning the total number of people homeless as per the April report is 9,652 which is a slight reduction.
But the ICHH says: "Yet again we are seeing people being removed without any proper explanation as to why."
In a statement, Housing Minister Eoghan Murphy said a "categorisation issue arose" in the compilation of the March figures and was corrected.
"Ongoing work in this area in the context of the April report has identified a further 18 households in Meath (45 people) and 65 households in Dublin (252 people) who are in homes rather than in emergency accommodation.
"The figures in the report reflect this", he said.