If you’re a tenant and want to terminate the rental agreement, this must be done with a signed notice letter. You’ll find a standard example here.
Make sure to follow the agreed notice period. Termination is only possible at the end of a calendar month (so if notice is sent on, for example, 14 March, it will be treated as if sent on 31 March).
Are there multiple tenants listed on the agreement? Then each tenant must sign the notice individually. According to the rental agreement, the letter must be sent by bailiff’s writ or registered mail.
Always check with your landlord or property manager whether a signed notice by email (with confirmation of receipt) is also accepted.