09 March 2026
Changing trading conditions, business growth, downsizing, or the shift toward hybrid working can all leave tenants with more space or more financial commitment than they need.
If you’re renting commercial premises in Dorset, including Bournemouth, Christchurch, or Poole, you may be considering ways to reduce your costs or exit your lease early. Two common solutions are assigning the lease or subletting the premises.
While both options can offer flexibility, they come with legal obligations and financial risks. Understanding how they work is essential before making a decision.
Assignment vs Subletting: What’s the Difference?
Although both options involve bringing another party into the premises, the legal structure is very different.
Assignment
An assignment transfers the tenant’s entire interest in the lease to a new tenant (known as the assignee). The assignee takes over the lease and begins paying rent directly to the landlord.
In theory, this allows the original tenant to exit the lease completely. However, this isn’t always the clean break many tenants expect.
In many cases, landlords require the outgoing tenant to sign an Authorised Guarantee Agreement (AGA). This means the former tenant guarantees the assignee’s obligations under the lease. If the assignee defaults, the landlord may pursue the original tenant for losses.
Subletting
A sublet works differently. The original tenant remains bound by the lease but grants a sublease to a third party.
In this arrangement:
This means that if the subtenant fails to pay rent or breaches the sublease, the landlord can still hold the head tenant responsible.
Landlord Consent: A Key Legal Requirement
Most modern commercial leases contain alienation clauses, which restrict assignment or subletting without the landlord’s written consent.
Under English law, if a lease states that consent is required, the landlord must not unreasonably withhold it. The landlord must also respond within a reasonable time and provide reasons if consent is refused.
However, there is no fixed statutory deadline. Delays are common when tenants fail to provide sufficient information with their application.
For businesses across Bournemouth, Christchurch and Poole, preparing a complete application early can significantly speed up the process.
What Information Landlords Usually Ask For
Before granting consent, landlords typically want reassurance that the proposed tenant is financially stable and suitable for the property.
Common requests include:
Providing this information promptly can make the difference between a smooth transaction and a prolonged delay.
Subletting: Ongoing Risks for the Head Tenant
Subletting can be an effective way to reduce unused space, but tenants must understand that the legal responsibility does not pass to the subtenant.
The head tenant remains responsible for:
If the subtenant fails to meet their obligations, the landlord will still look to the head tenant.
Many leases also restrict subletting part of the premises, meaning tenants may only sublet the entire property. This can be particularly relevant for office buildings or multi-floor premises.
Security of Tenure and the Landlord and Tenant Act 1954
When granting a sublease, landlords often require it to be contracted out of the security of tenure provisions under the Landlord and Tenant Act 1954.
This means the subtenant does not automatically gain the right to renew the lease at the end of the term.
The contracting-out process must follow a specific statutory procedure. If this is not done correctly, the subtenant may gain renewal rights unintentionally, which can create complications for both landlord and tenant.
Costs Tenants Should Expect
Most leases require tenants to pay the landlord’s reasonable legal and administrative costs when applying for consent to assign or sublet.
These costs usually apply even if consent is refused, provided the lease allows it.
In practice, fees can range from several hundred to several thousand pounds plus VAT, depending on the complexity of the transaction.
Market Trends Affecting Commercial Tenants
Commercial property markets across Dorset have seen increasing demand for flexible occupation arrangements.
As a result:
However, many leases restrict profit-making from subletting or require tenants to share any excess rent with the landlord.
Common Pitfalls Tenants Should Watch For
Before assigning or subletting a lease, tenants should carefully review:
Overlooking these issues can lead to unexpected liabilities or disputes.
Getting the Right Advice
Assigning or subletting a commercial lease can be an effective strategy for managing costs or restructuring your business space. However, the legal details of the lease, the strength of the incoming party, and the process for obtaining landlord consent all play an important role in ensuring the transaction runs smoothly.
For businesses across Bournemouth, Christchurch, Poole and the wider Dorset area, taking legal advice early can help prevent delays, reduce risk, and ensure your commercial objectives are met.
Need Advice on Assigning or Subletting Your Lease?
If you’re considering assigning or subletting your commercial lease, our experienced commercial property team can help guide you through the process.
We regularly support businesses across Dorset, including Bournemouth, Christchurch and Poole, with practical legal advice tailored to their commercial needs.
Contact us today to discuss your options and ensure your lease strategy works for your business. Call 01202 526343 or send us an enquiry through our website to arrange a consultation.
