You have found another flat and a person who would like to take over your current one. That seems to organise the earlier move-out. What may still be open, however, is whether and on what date your own tenancy ends. A proposed new tenant, the selection of a new contracting party and your release from existing obligations are different decisions. They should also remain separate in communication.
Read the existing contract first
Note which contracting parties are involved and what term or termination provision is stated in your paperwork. Check for any addenda and possible special agreements on an early termination. The individual effect cannot be determined solely by whether the contract contains a printed end date. If there is any uncertainty, seek professional review before making a firm promise to the next person.
§ 542 BGB distinguishes the termination of indefinite and fixed-term tenancies according to the respective statutory requirements. The mere naming of an interested person is not provided there as a general automatic means of termination. [BGB] Whether you have a claim based on a specific agreement or particular constellation must be assessed separately. No general rule is asserted here that a certain number of proposed persons will always suffice.
Phrase a proposal as a proposal
Our editorial recommendation: First inform the letting side which earlier termination date you are aiming for and that you could nominate an interested person. Ask about the intended selection and decision-making process. Do not promise that person an already agreed tenancy if such a decision has not yet been made.
Limit the first disclosure to the necessary information and an agreed contact route. Do not send personal evidence of another person unsolicited in a mass email. A possible successor should be able to submit their details for verification to the responsible party themselves. The organisational procedure does not replace a data-protection assessment on a case-by-case basis.
Obtain a clear confirmation of your release
If an earlier termination is in principle under consideration, clarify the exact content of the agreement. Which date applies? Are conditions to be met? Who must give consent? What happens if the new person ultimately does not sign? A friendly message about a conversation that took place can leave these questions unanswered.
Example, editorially invented: A tenant proposes 15 June as the handover day. The interested person would only sign a contract from July. The two dates are not automatically identical. The previous tenant therefore clarifies what arrangement is actually to be agreed for his payment obligation in the interim, instead of inferring an earlier release solely from the later commencement.
Taking over furniture is a separate matter
A kitchen or other items can trigger separate agreements. Keep apart what belongs to the rented property and what you may offer yourself. A private agreement on furniture does not replace either the letting side's selection decision or the termination of your contract. Do not pay or accept money on the sole assumption that this makes the entire flat takeover bindingly settled.
Editorial practical tip: Maintain a separate status for each agreement with date, persons involved and open issues. That way you can recognise whether only the furniture purchase has been agreed or also the actual end of the tenancy. With unclear conditions, a written, traceable clarification is more valuable than a long chain of mutually conflicting promises.
Organise return and final accounting separately
Only agree the return date once matters have been clarified. Document keys, condition and required meter readings. Record to whom the return is made and which points remain open. That a new person already gains access does not automatically answer all questions about your own proper handover.
Keep the final agreements and evidence together. If there is a dispute about payments, damages or the end of the contract, seek suitable advice in good time. The process does not offer a blanket legal solution for every contract. However, it helps you avoid a common mistake: a suitable successor and an effectively terminated own contract are two different outcomes that must be coordinated with each other.