Rent increase rules vary between Australian states and territories, so your landlord must follow the requirements that apply where you live. Generally, increases need to be provided in writing and may be restricted during a fixed-term agreement or to certain intervals. Check your lease and your state or territory’s tenancy authority website for the required notice period and frequency limits. If the increase seems improper or unaffordable, you can ask the landlord or agent to discuss it and seek help through the relevant tenancy service or tribunal.