If you are on a fixed term tenancy agreement you can only move out if you have permission from the landlord to find a replacement for yourself (i.e. re-assign the tenancy). Most landlords/property managers will allow this provided you continue to pay rent until a new tenant takes over.
Once you have permission from the landlord you need to find your replacement. You must take into consideration the remaining flatmates’ needs, as long as they’re reasonable. Word of mouth, Facebook pages like Otago Flatting Goods, and Trade Me are good places to advertise your room. In some cases, the landlord might choose to advertise the room themselves and can recover the cost of this from you. Once you’ve found someone who’s interested and a good fit, the remaining flatmates and landlord have to agree to this person.
Landlords can recover any reasonable costs of replacing you, such as advertising and credit checks. If they are charging a seemingly large lump sum, you may ask them for a breakdown of what this fee covers, to ensure the fee charged is justified.
The new tenant takes over your responsibilities under the tenancy agreement. The change must be recorded in writing by filling out a Change of Tenant form, which must be signed by the landlord and all the remaining tenants. This also means the bond will be under the new tenant’s name, so make sure you discuss bond arrangements with your replacement (the most straightforward method is having them pay you the amount for your share of the bond directly when you move).
If the paperwork isn’t done correctly you will still be legally responsible for paying rent and for the condition of the property at the end of the tenancy. This could create a lot of hassle and end up costing you a lot of money!