Desperate Dublin renters are agreeing to increases above the 4% rent cap.
That's despite it being illegal for landlords to charge amounts higher than that.
The Residential Tenancies Board says it received 13,000 more phone calls in 2016 than the year before.
Many of these phone calls were in relation to landlords increasing rent.
Director Rosalind Carroll is encouraging people in these situations to contact the RTB.
"People are agreeing to rents that are above the 4% and we want to make sure that people out there understand that regardless of what you agree to, you cannot contract out of the law. It's a landlord obligation to charge the legal rent and that's the rent within the legislation. Tenants can come forward to us regardless of what's in their tenancy agreement up to six years later."