Purpose
The entire dispute lies between the reservation of permission and the claim to consent: § 540 BGB prohibits transfer of use without permission, § 553 BGB gives the tenant, under certain conditions, a claim to it. Whoever wrongfully refuses permission is liable for damages; whoever sublets without permission risks termination. This skill determines the boundary, quantifies the subletting surcharge and addresses the sanctions in both directions.
Inputs
- Tenancy agreement: clauses on transfer of use, number of persons, usage requirements
- Planned arrangement: partial or full transfer, number of rooms, period, identity of the third party
- Legitimate interest: reason (loss of income, stay abroad, partner moving in, care)
- Apartment size and current occupancy (for the overcrowding limit)
- Permission request: wording, date, named person, landlord's response
- For short-term letting: state-law rules on unauthorized changes of housing use, registration obligations
- In case of sanction: warnings, duration and scope of unauthorized transfer, rental income
Sub-agent architecture
The review is carried out in prose by specialized steps; this skill deliberately does not include a agentsblock (tenancy-law convention). A elements reviewer first clarifies whether a transfer of use requiring permission exists at all — taking in close relatives does not. An entitlement reviewer assesses the legitimate interest under § 553 (1) BGB and the grounds for refusal. A surcharge calculator determines the reasonableness limit and the appropriate subletting surcharge. A sanctions reviewer builds the warning and termination and in parallel examines the claim against the subtenant. A public-law reviewer addresses unauthorized changes of housing use and registration obligations.
Procedure
1. Transfer of use requiring permission (§ 540 (1) BGB)
Without the landlord's permission , the tenant is not entitled to transfer use of the leased property to a third party, in particular to sublet it. If the landlord refuses permission, the tenant may terminate the tenancy extraordinarily with the statutory notice period, unless there is an important reason in the person of the third party (§ 540 (1) sentence 2 BGB) — an often overlooked special right of termination.
No transfer of use requiring permission includes:
- taking in the spouse or registered civil partner as well as minor children,
- visits of the usual duration (guideline: up to about six weeks),
- the taking in of care staff, insofar as necessary for care.
By contrast, permission is required for the move-in of the unmarried partner, the taking in of adult children to a significant extent, and any paid subletting. For fault on the part of the subtenant, the tenant is liable under § 540 para. 2 BGB as for their own.
2. Claim for permission of partial subletting (§ 553 para. 1 BGB)
If, for the tenant after conclusion of the lease agreement , a legitimate interestarises to leave a part of the residential space to a third party for use, the tenant may demand permissionfrom the landlord. Requirements:
- Subsequent arising of the interest — a plan already existing at the time of conclusion of the contract is not sufficient.
- Legitimate interest — any reasonable, comprehensible personal or economic interest: loss of income, desire for cost relief, move-in of a partner, need for care, longer stay abroad while maintaining the center of life in the dwelling (BGH, judgment of 11.06.2014 – VIII ZR 349/13, https://dejure.org/dienste/vernetzung/rechtsprechung?Gericht=BGH&Datum=2014-06-11&Aktenzeichen=VIII%20ZR%20349/13).
- Only a part of the residential space — the tenant must retain possession of the dwelling; one room that the tenant continues to use or keeps for their belongings is sufficient. Complete transfer does not fall under § 553 BGB.
Grounds for refusal (para. 1 sentence 2): The claim does not exist if, in the person of the third party, there is an important reason (for example previous misconduct in the building), if the residential space would be excessively occupied , or if the transfer cannot reasonably be expected of the landlord for other reasons . The landlord may learn the identity of the subtenant; there is no claim to comprehensive information about the subtenant's financial circumstances.
Legal consequence of unjustified refusal: The tenant can sue for permission and claim damages under § 280 para. 1 BGB — in the amount of the lost sublease rent.
3. Sublease surcharge (§ 553 para. 2 BGB)
If the transfer can reasonably be expected of the landlord only with an appropriate increase in the rent, the landlord may make permission dependent on it. The surcharge is not a participation in the sublease rent, but compensation for the additional burden — greater wear and tear, increased consumption-dependent costs, increased risk. Its amount must be justified; flat percentage rates of the sublease or the main lease are contestable. The actual additional burden and, where applicable, the surcharge rules for price-controlled housing serve as guidance. Note: The surcharge is not a rent increase under Section 558 of the German Civil Code (BGB) and is subject neither to the cap limit nor to the waiting period; it ceases when the subletting ends.
4. Short-term letting and unauthorized changes of housing use
The Commercial short-term letting via platforms is generally not covered by a general subletting permission — it has a different character from the transfer to a specific subtenant and requires separate, express authorization. In addition, public-law restrictions apply: numerous federal states and municipalities have issued prohibitions on unauthorized changes of housing use with approval and registration requirements; violations are subject to fines and at the same time constitute a breach of contract vis-à-vis the landlord. The relevant state and local law must be examined separately.
5. Sanctions for unauthorized transfer of use
Warning and cessation: The landlord may demand cessation and must generally issue a warning (Section 543(3) of the German Civil Code (BGB)). The warning must specifically identify the objected transfer and set a deadline for termination.
Extraordinary termination (Section 543(2) sentence 1 no. 2 of the German Civil Code (BGB)): It requires a significant legal violation. An overall assessment is required; the unauthorized transfer of a single room, for which a claim to permission under Section 553 of the German Civil Code (BGB) would have existed, generally does notsupport it. The situation is different in the case of complete, commercial or permanent transfer despite a warning.
Ordinary termination (Section 573(2) no. 1 of the German Civil Code (BGB)): culpable, not insignificant breach of contract — the practically more robust variant; always declare it in the alternative. In-depth: /mietrecht:fristlose-kuendigung-543.
Surrender of the sublease rent? A claim by the landlord for payment of the sublease rent obtained generally does notexist; at most, damages may be considered if damage is proven.
6. Claims against the subtenant (Section 546(2) of the German Civil Code (BGB))
There is no contractual relationshipbetween the landlord and the subtenant. After termination of the main lease, however, the landlord may demand return directly from the third party (Section 546(2) of the German Civil Code (BGB)); in addition, the claim for surrender under Section 985 of the German Civil Code (BGB)applies. In eviction proceedings, the subtenant must also be sued — a title against only the main tenant is not enforceable against him; Section 940a(2) of the German Code of Civil Procedure (ZPO) helps only if possession was obtained without the landlord's knowledge. The sublease relationship does not automatically end with the main lease; the subtenant retains claims against the main tenant. In depth: /mietrecht:raeumungsklage.
Sources
Statutes
- § 540 BGB, § 553 BGB, § 546 BGB, § 985 BGB
- § 543 BGB, § 573 BGB, § 280 BGB, § 558 BGB
- § 940a ZPO; state laws prohibiting misappropriation and municipal bylaws (to be examined separately)
Commentaries
- Blank, in: Schmidt-Futterer, Mietrecht, 15th ed. 2023, § 553 BGB marginal no. 1 et seq.
- Bieber, in: MüKoBGB, 9th ed. 2023, § 540 marginal no. 1 et seq.; § 553 marginal no. 1 et seq.
- Weidenkaff, in: Grüneberg, BGB, 84th ed. 2025, § 553 marginal no. 1 et seq.
Case law
- BGH, judgment of 11.06.2014 – VIII ZR 349/13 (legitimate interest in subletting during a longer stay abroad; damages for wrongfully refusing permission) — verified: https://dejure.org/dienste/vernetzung/rechtsprechung?Gericht=BGH&Datum=2014-06-11&Aktenzeichen=VIII%20ZR%20349/13
- For the assessment of the subletting surcharge under § 553 para. 2 BGB, the relevant case law is to be consulted
[unverifiziert - prüfen]. - For the materiality threshold under § 543 para. 2 sentence 1 no. 2 BGB in the case of unauthorized subletting of a single room, the relevant BGH case law is to be consulted
[unverifiziert - prüfen].
Drafting aid — application for permission to sublet (§ 553 para. 1 BGB)
Sehr geehrte Damen und Herren,
hiermit beantrage ich gemäß § 553 Abs. 1 BGB die Erlaubnis, einen Teil der
von mir gemieteten Wohnung <Anschrift> unterzuvermieten.
1. Berechtigtes Interesse: Seit <Datum> <konkreter Anlass: Reduzierung
meines Einkommens durch …, berufsbedingter Auslandsaufenthalt vom
<Datum> bis <Datum>, Zuzug meiner Partnerin>. Dieses Interesse ist erst
nach Abschluss des Mietvertrags entstanden.
2. Umfang: Überlassen werden soll ausschließlich das Zimmer <…> mit
<…> m². Die übrigen Räume nutze ich weiterhin selbst; meine Möbel und
persönlichen Gegenstände verbleiben in der Wohnung. Ich behalte den
Gewahrsam und meinen Lebensmittelpunkt in der Wohnung.
3. Person des Untermieters: <Name, Geburtsdatum, derzeitige Anschrift,
Beruf>. Gründe, die in seiner Person einen wichtigen Grund im Sinne des
§ 553 Abs. 1 S. 2 BGB darstellen könnten, liegen nicht vor.
4. Belegung: Die Wohnung ist mit <…> m² für <…> Personen ausreichend
groß; eine Überbelegung tritt nicht ein.
5. Untermietzuschlag: Soweit Ihnen die Überlassung nur gegen eine
angemessene Erhöhung der Miete zuzumuten ist, bitte ich um Mitteilung
und konkrete Begründung des Zuschlags nach § 553 Abs. 2 BGB.
Ich bitte um Ihre Erlaubnis bis zum <Datum>. Auf mein Recht, die Erlaubnis
gerichtlich durchzusetzen und Schadensersatz in Höhe der entgangenen
Untermiete geltend zu machen, weise ich vorsorglich hin.
Mit freundlichen Grüßen
Output format
UNTERVERMIETUNG §§ 540, 553 BGB — Prüfung — <Mandat-ID> — <Datum>
I. Erlaubnispflicht (§ 540 Abs. 1) [ja / nein — Ehegatte, Kind, Besuch, Pflege]
II. Umfang [Teil der Wohnung / vollständig]
Gewahrsam des Mieters bleibt [✅ / ❌ → § 553 BGB nicht anwendbar]
III. Berechtigtes Interesse (§ 553 Abs. 1) <Anlass>
Nachträglich entstanden [✅ / ❌]
IV. Verweigerungsgründe (§ 553 Abs. 1 S. 2)
- Wichtiger Grund in der Person [nein / ja <…>]
- Übermäßige Belegung [nein / ja]
- Sonstige Unzumutbarkeit [nein / ja <…>]
V. Untermietzuschlag (§ 553 Abs. 2) <Betrag> [begründet / pauschal ⚠️]
VI. Kurzzeitvermietung / Zweckentfremdung [N/A / Genehmigung erforderlich /
Registrierungspflicht]
VII. Sanktionen bei unerlaubter Überlassung
- Abmahnung (§ 543 Abs. 3) [erfolgt / erforderlich]
- Fristlos (§ 543 Abs. 2 Nr. 2) [Erheblichkeit ✅ / ❌]
- Ordentlich (§ 573 Abs. 2 Nr. 1) [tragfähig / nicht]
- Herausgabe der Untermiete [kein Anspruch]
VIII. Untermieter [mitzuverklagen — § 546 Abs. 2, § 985 BGB]
IX. Sonderkündigungsrecht des Mieters [§ 540 Abs. 1 S. 2 BGB — Frist <…>]
Ergebnis: <Erlaubnis geschuldet / verweigerbar / Kündigung tragfähig>
Risiko: [🟢 / 🟡 / 🔴]
Risks / typical mistakes
- Permission refused without reason — the tenant can sue for it and claim damages in the amount of the lost sublease rent (§ 280 para. 1 BGB).
- § 553 BGB applied to full transfer — the claim exists only for a part of the residential space; in the case of full transfer, the permission requirement under § 540 BGB remains.
- Interest already existed at the time the contract was concluded — then there is no claim under § 553 para. 1 BGB.
- Subletting surcharge assessed as a flat rate — the surcharge must reflect the concrete additional burden and be substantiated; it is not participation in the sublease rent.
- Short-term letting treated as subletting — it is not covered by a general permission and may additionally be prohibited under misappropriation law.
- Extraordinary termination without prior warning — under § 543 para. 2 sentence 1 no. 2 BGB, unlike in the case of payment default, a warning is generally required.
- Materiality threshold overestimated — if a claim to permission existed under § 553 BGB, the unauthorized transfer of a room generally does not support extraordinary termination.
- Subtenant not sued as co-defendant — the eviction order against the main tenant is not enforceable against him.
- Tenant's special right of termination overlooked — § 540 para. 1 sentence 2 BGB gives him an extraordinary right of termination with statutory notice in the event of refusal.