Too many landlords are not protecting their tenants' deposits, warn Citizens Advice and the lodging charity Shelter.
Since last April, landlords in England and Cymru offering new assured shorthold occupancy understandings must fall in one of three functionary schemes.
These safeguard sedimentation money in the event of a dispute, but some landlords are failing to comply.
The authorities take a firm stands the strategies are working well, and have got so far protected almost a million sedimentations worth £900m.
Ben Ferguson from Peterborough paid a sedimentation of £825 to a letting agent in May 2007.
This money should have got been covered under the legislation, but his agent did not subscribe up with any of the schemes, and subsequently went out of business, leaving Ben out of pocket.
He told Radio 4's Money Box programme the authorities should make more than to raise consciousness of the schemes.
"They really necessitate to do renters aware that these sedimentations necessitate to be protected.
"A batch of people don't cognize about these strategies and what the agent's duties are."
The job is, how make you clamp down on it?
Saint David Young, Reading
The full scale of measurement of the job is not clear, but Shelter states it acquires phone calls every hebdomad about sedimentations still not being protected.
And Citizens Advice states its bureaux around the state regularly describe ailments about the same issue.
"It's clearly good news that a million sedimentations are protected," said Liz Phelps, societal policy advisor at Citizens Advice.
"But it's now quite clear that we are seeing far too many renters who knew nil about it and whose sedimentations weren't protected," she added.
If a landlord makes not subscribe up to a scheme, it is up to the renter to take their landlord or agent to the county court, which have the powerfulnesses to present a renter three modern times their deposit.
Civil action intends people have got got to have the courageousness to travel to the county courts
Marveen Smith, partner, Pain Smith
At least one renter have already successfully taken her landlord to court.
Marveen Ian Smith is a place canvasser who also moves as a legal advisor to The Occupancy Deposit Scheme, one of the three bodies.
She would wish more than renters to utilize the tribunal system, but acknowledges many may be too daunted to make so:
"Civil action intends people have got got to have the courageousness to travel to the county courts.
"There's no existent alternative."
John Socha is frailty chair of the National Landlords Association and manager of another strategy called mydeposits.
He believes the bulk of landlords are signing up, and anticipates that legal action of this kind volition go less necessary:
"You'll have got to happen a renter who didn't cognize about the scheme, and a landlord who didn't cognize about the scheme, so that will go increasingly less and less."
Others are calling on the authorities to do alterations so it is not solely the tenant's duty to implement the legislation.
Greg Mulholland, Liberal Democrat military policeman for Leeds North West, political campaigns on lodging issues:
"The authorities have got to be bold here and expression at setting up an federal agency or resourcing the strategies themselves to have enforcement arms," he said.
The Department for Communities and Local Government (DCLG) is responsible for the sedimentation schemes.
A spokesman said it believes the strategies are protecting tenants' sedimentations very effectively:
"Nearly 1 million sedimentations and £900m have got been safeguarded under the strategy in the first twelvemonth alone."
There were no programs to revize the "tough enforcement powers" already in place, he added, citing the courts' ability to impose "hefty" mulcts on landlords who failed to comply.
BBC Radio 4's Money Box was broadcast on Saturday, 10 May 2008 at 1204 BST.