Calls to Tenancy Services have jumped by more than a third in the last month compared to late last year.
The surge is partly down to a seasonal peak in fixed-term tenancies ending but also changes to rental laws, including no-cause evictions, coming into effect last month, Tenancy Services spokesperson Steve Watson said.
Landlords are also contacting the services for advice in the lead-up to the Healthy Home Standards deadline approaching in July, he said.
Total calls in February jumped by nearly 17,000 calls compared with November last year.
Tenancy Services said staff are aware of delays and are looking to improve its services.