Insight · 5 min read

Subletting Commercial Leases: Process and Pitfalls

Subletting lets commercial tenants sublet all or part of the demise to a third party — critical flexibility for space downsizing or partial exit. This guide explains the process, landlord consent, and typical pitfalls.

Published 2026-04-15Hampstead Renovations Commercial

The alienation clause

Every commercial lease has an alienation clause governing subletting, assignment and sharing occupation. Standard wording requires 'landlord's consent not to be unreasonably withheld'. Some clauses are absolute (consent impossible); most are qualified.

Subletting vs assignment

Typical process

  1. Identify sub-tenant

    Approach via broker or direct. Covenant strength material to landlord consent.

  2. Landlord application

    Tenant's solicitor submits alienation application with sub-tenant covenant, proposed sublease terms.

  3. Landlord surveyor review

    4–8 weeks typical. Surveyor checks: sub-tenant covenant, use compatibility, repairing obligations, rent level.

  4. Consent and documentation

    Landlord issues licence to sublet or licence to assign. All parties sign.

  5. Sublease execution

    Main tenant and sub-tenant sign sublease. Sub-tenant typically inherits repairing obligation.

Restrictions that typically apply

Costs

What we do

Where subletting involves physical reconfiguration — partitioning a floor, creating a separate entrance — we deliver the CAT B works alongside. See Office Partitioning, Office Fit-Out.

FAQs

Can we sublet part of the demise?

Yes, subject to the lease. Some leases prohibit part-subletting; most permit with consent.

Who pays rent to whom?

Sub-tenant pays main tenant; main tenant continues to pay landlord. Main tenant liable to landlord for full rent regardless of sub-tenant performance.

Need commercial expertise on this?

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