Commercial Sublease Agreement: What Businesses Must Include

If you’re renting commercial premises and you’ve got unused space (or you’re looking to reduce overheads), subletting can feel like a smart, flexible move.

But here’s the catch: in the UK, subletting without the right paperwork (and the right permissions) can put your lease at risk, trigger disputes with your landlord, and leave you carrying costs if the subtenant stops paying.

A well-drafted subtenant agreement is the key legal document that sets expectations, protects your position as tenant, and helps keep your business running smoothly while someone else occupies the space.

This article is general information for UK businesses and isn’t legal advice. Lease terms and the right process can vary depending on your headlease, your property, and how the arrangement is structured.

Below, we’ll walk you through what a subtenant agreement is, what you need to check before you sublet, and the key clauses UK businesses should include in a commercial sublease.

What Is A Subtenant Agreement (And How Is It Different From A Lease)?

A subtenant agreement (often called a commercial sublease) is a contract where you (the existing tenant) grant another business (the subtenant) the right to occupy all or part of your premises for a period of time.

It’s different from:

• An assignment – where you transfer your lease to a new tenant and step out (subject to landlord consent and other rules).
• A licence to occupy – which is often more flexible and less “property-like”, but can be risky if it’s drafted in a way that looks like a lease in practice. In some cases, a licence to occupy is appropriate, but you need to get the structure right.

In a typical sublease structure:

• The landlord leases the premises to you (the head tenant).
• You then sublet to the subtenant under a separate agreement.
• You usually remain responsible to the landlord for the headlease obligations (including rent and repairs), even if the subtenant is paying you.

That last point is why getting your subtenant agreement right matters so much. If the subtenant breaches their obligations, the landlord can still pursue you under the headlease.

Before You Sublet: The Checks You Need To Do First

Before you negotiate terms with a subtenant, make sure you’re legally allowed to sublet and that you’re not accidentally triggering a breach of your headlease.

1) Check Your Headlease “Alienation” Clause

Most commercial leases contain an alienation clause (this is the part dealing with assignment, subletting, sharing occupation, and sometimes concessions like serviced space).

Common setups include:

• Subletting is prohibited (full stop).
• Subletting is allowed with landlord consent (often “consent not to be unreasonably withheld or delayed”).
• Only whole-premises subletting is allowed (subletting part may be banned).
• Subletting is allowed only on certain terms (e.g. rent must be at market rate, sublease must exclude security of tenure, or must be contracted out of the Landlord and Tenant Act 1954).

If your lease is complex, it’s usually worth getting it reviewed before you move forward. A Commercial Lease Review can help you understand what you can (and can’t) do under your existing lease.

2) Get Landlord Consent (If Required)

If your headlease requires consent, don’t rely on informal emails or assumptions. You’ll typically need a formal written licence to underlet or written consent from the landlord (and sometimes their solicitor).

Subletting without required consent can lead to:

• breach of lease and enforcement action (including forfeiture risk in serious cases);
• issues with your insurance cover;
• problems when you later try to renew, assign, or exit your lease.

3) Consider Security Of Tenure (Landlord And Tenant Act 1954)

Many business owners don’t realise that certain tenants can gain rights to renew a commercial lease under the Landlord and Tenant Act 1954 (known as “security of tenure”), unless the lease is properly excluded (“contracted out”).

Whether your subtenant should have renewal rights depends on your goals and your headlease terms. For example:

• If you need the premises back on a fixed date, you may want the sublease contracted out.
• If your headlease is contracted out, your landlord might require your sublease to be contracted out too.

Contracting out has a specific legal process and must be done before the sublease is granted, so timing (and paperwork) matters.

4) Work Out The Commercial Practicalities

Before you put pen to paper, get clear on your “non-negotiables”, such as:

• Is the subtenant taking the whole premises or just part?
• Do you need shared access (reception, toilets, storage, meeting rooms)?
• Who is paying utilities, business rates, service charges, and insurance?
• Do you need flexibility to end early (break clause) if your business changes?

These practical questions shape what your subtenant agreement needs to say.

What To Include In A Subtenant Agreement: The Key Clauses For UK Businesses

A strong subtenant agreement isn’t just about rent and dates. It’s about aligning the subtenant’s obligations with your headlease, and making sure you have enforceable rights if something goes wrong.

Below are key clauses most UK businesses should consider in a commercial sublease.

Parties, Premises, And The Sublet Area

Start with clarity. The agreement should accurately identify:

• the legal names and addresses of you and the subtenant (and company numbers where relevant);
• the premises being sublet (whole or part);
• a plan showing the sublet area if it’s part of the premises (this avoids disputes later).

Term, Start Date, And End Date

Set out:

• the sublease term (fixed term, rolling, or periodic if appropriate);
• any rent-free period;
• handover dates and access arrangements.

A common commercial trap is ending up with a sublease that outlasts your headlease. Usually, your sublease must end before (or at least no later than) your headlease ends, otherwise you can’t grant what you don’t have.

Rent, Payment Mechanics, VAT, And Rent Reviews

Your subtenant agreement should clearly cover:

• Rent amount and whether it’s inclusive/exclusive of VAT;
• payment frequency (monthly/quarterly) and payment method;
• interest on late payments and recovery costs;
• rent review provisions (if the sublease is long enough to justify one).

If your headlease has a rent review, think about whether (and how) you’ll pass that through to the subtenant. Otherwise you could be stuck paying the increase while the subtenant pays the old rent.

Deposit, Guarantees, And Other Security

Even with a friendly subtenant, it’s risky to rely on goodwill alone. Consider:

• a rent deposit (held on agreed terms, with rules on deductions and return);
• a personal guarantee (common where the subtenant is a new company);
• additional protections such as upfront rent or a guarantor deed in higher-risk situations.

Security terms should be consistent with what your headlease allows (some leases restrict taking deposits or require landlord notification).

Permitted Use (And Compliance With The Headlease)

“Use” clauses are a big deal in commercial property.

Your subtenant agreement should set out:

• what the subtenant can use the premises for (and what they can’t);
• any restrictions on noise, odours, footfall, or opening hours;
• a requirement that the subtenant complies with the headlease obligations that relate to the premises.

This helps prevent the subtenant from doing something that breaches your lease (for example, operating a use that needs special consent or planning permission).

Repairs, Maintenance, And Condition Of The Premises

Repair obligations are one of the most common sources of disputes.

Your subtenant agreement should be clear about:

• who is responsible for internal repairs;
• what happens with shared areas (if you’re subletting part);
• any obligations to redecorate at the end of the term;
• whether the premises are taken “as is” or with agreed works completed first.

It’s also smart to attach a schedule of condition (photos and notes) so there’s a baseline for end-of-term discussions.

Service Charges, Utilities, And Insurance

Make sure your subtenant agreement spells out:

• which outgoings the subtenant pays (service charge, utilities, internet, cleaning, waste);
• how costs are calculated for shared occupation (fixed split vs metered vs percentage);
• insurance responsibilities (who insures what, and whether the subtenant must reimburse you).

If your headlease requires the tenant to insure and recover the premium, you’ll usually want the subtenant to reimburse you for the relevant portion.

Alterations, Signage, And Fit-Out

Most headleases restrict alterations, signage, and fit-outs without landlord consent.

Your subtenant agreement should address:

• what alterations (if any) are allowed;
• who owns fixtures and fittings at the end of the term;
• reinstatement obligations (returning the premises to its previous condition).

This is where businesses can accidentally create a big cost. If the subtenant installs a fit-out and leaves, the landlord may still expect you to reinstate under the headlease.

Assignment, Subletting By The Subtenant, And Sharing Occupation

You’ll usually want tight control over who occupies your premises.

Consider clauses that:

• prohibit the subtenant from subletting, assigning, or sharing occupation without your written consent (and landlord consent if required);
• require the subtenant to provide information about any permitted occupier;
• allow you to refuse consent in reasonable scenarios (e.g. reputational risk, financial risk, use restrictions).

Break Clauses And Early Termination

Break clauses can be very useful for small businesses because your needs change quickly.

If you include a break clause, make sure you cover:

• who can exercise the break (you, the subtenant, or both);
• notice periods and the required method of notice;
• conditions (e.g. rent up to date, vacant possession, reinstatement completed).

Default, Enforcement, And Ending The Arrangement

If the relationship goes sideways, your subtenant agreement needs to give you workable options.

This part often covers:

• what counts as a breach (non-payment, insolvency, illegal use, repeated nuisance);
• remedies and timeframes to fix the breach;
• how forfeiture / ending the sublease would work (and that taking back possession usually needs to follow the correct legal process);
• what happens to keys, access cards, and security codes on exit.

It’s also worth thinking through how you’ll handle a situation where someone refuses to leave at the end of the term. The practical and legal steps depend on the agreement terms and the facts, and issues can escalate quickly if not handled properly. Planning ahead is much easier than trying to untangle it later.

How To Put A Subtenant Agreement In Place (Without Creating Extra Risk)

Once you’ve agreed the commercial deal points, it’s tempting to move fast. But with property arrangements, speed without structure can cause expensive headaches.

A sensible process usually looks like this:

1) Agree Heads Of Terms

Write down the main deal points so you and the subtenant are aligned:

• sublet area
• term
• rent and outgoings
• deposit/security
• any works or fit-out
• break options

This doesn’t replace the formal subtenant agreement, but it reduces misunderstandings.

2) Get Landlord Consent And Any Required Documents

Depending on your headlease, the landlord may require:

• a formal licence to underlet;
• an approved form of sublease;
• direct covenants from the subtenant; or
• evidence that the subtenant is contracted out of the 1954 Act.

3) Confirm Whether The Sublease Needs To Be A Deed

Many commercial subleases are completed as deeds. As a general rule, a lease for more than 3 years must be made by deed, and shorter arrangements can still end up being documented as deeds depending on the structure and what the headlease (or landlord) requires.

Because signing formal documents incorrectly can create enforceability problems, it’s worth confirming execution requirements early. Even basics like who can witness a signature can matter when deeds are involved.

4) Make Sure Your Legal Documents Match The Reality

If the subtenant will share space with you, your agreement should match how the space is actually used day-to-day, including:

• shared access rules and security
• quiet enjoyment and nuisance expectations
• rules for common areas
• IT/network arrangements

When the legal terms don’t match reality, disputes are much more likely (and much harder to resolve).

5) Don’t Rely On A Template

It’s easy to find generic templates online, but commercial subletting is one area where “close enough” can become very expensive.

A properly drafted subtenant agreement should be tailored to your headlease terms, your premises, your risk profile, and your commercial goals. If you’re not sure whether your draft is doing what you need, a Contract Review can help you spot issues before you sign.

Key Takeaways

• A subtenant agreement is a key legal document for businesses subletting commercial premises, and it should be drafted to protect you as the head tenant (because you usually remain responsible under your headlease).
• Before you sublet, check your headlease for restrictions and consent requirements, and make sure you understand the impact of security of tenure under the Landlord and Tenant Act 1954.
• A strong subtenant agreement should clearly cover the premises and term, rent and outgoings, deposit/security, permitted use, repair obligations, insurance, alterations, and rules around assignment and subletting.
• Build in practical protections like clear default/termination rights and handover processes, so you can manage non-payment or end-of-term issues without unnecessary disruption.
• Don’t rely on generic templates-commercial subleases need to reflect your headlease and your real-world arrangements, otherwise you risk disputes or breaches.

If you’d like help drafting or reviewing a subtenant agreement, you can reach us at 08081347754 or team@sprintlaw.co.uk.