Assigning a business lease: the landlord’s consent, the authorised guarantee agreement and SDLT

By Instrukt, published by Joshua Giles. Updated 2 November 2026. How we write guides

Not legal advice. This page has not been reviewed by a solicitor.

The short answer

As of November 2026, a tenant of a business lease in England and Wales usually needs the landlord’s consent to assign it, and the landlord must not unreasonably withhold that consent. The landlord can ask for its reasonable legal costs and may require an authorised guarantee agreement. SDLT on an assignment is normally charged on the price, not the rent.

Can the landlord refuse, and what must it do?

A landlord may refuse, but only reasonably. Once the tenant serves a written application, the landlord owes a duty to the tenant to decide within a reasonable time, and to serve written notice of its decision (section 1(3)). The statute sets no fixed period for “a reasonable time”. The burden of showing that consent was given, that any condition was reasonable, or that a refusal was reasonable, is on the landlord (section 1(6)). The table summarises the duty.

PointWhat the law saysSource
TriggerThe duty arises when the tenant serves a written application.LTA 1988 s.1(3)
TimingThe landlord must decide within a reasonable time; no fixed period is set.LTA 1988 s.1(3)
RefusalIf consent is withheld, the written notice must give the reasons.LTA 1988 s.1(3)
Reasonable refusalFor the Act’s purposes, it is reasonable not to consent “only in a case where, if he withheld consent and the tenant completed the transaction, the tenant would be in breach of a covenant”.LTA 1988 s.1(5)
ConditionsConsent given subject to an unreasonable condition does not satisfy the duty.LTA 1988 s.1(4)
Burden of proofThe landlord must show that its consent, condition or refusal was reasonable.LTA 1988 s.1(6)
CostsThe landlord may require a reasonable sum for legal or other expenses.LTA 1927 s.19(1)(a)

What if the lease already agrees the grounds for refusal?

For a qualifying lease, the landlord and tenant can agree in the lease the circumstances in which the landlord may withhold consent, and any conditions on which consent may be given. If the landlord withholds consent on a ground in that agreement, and the ground exists, it is not treated as unreasonable. The same applies to conditions agreed in the lease (section 19(1A)). Section 19(1A) also limits the 1988 Act duty for a qualifying lease, because the agreed grounds and conditions are treated as reasonable.

A “qualifying lease” is a new tenancy for the purposes of section 1 of the Landlord and Tenant (Covenants) Act 1995, other than a residential lease (section 19(1E)). Check whether your lease is one, and read the agreed grounds, before you rely on them.

Can the landlord require an authorised guarantee agreement?

Yes, if the condition is lawfully imposed. Section 16(3) of the Landlord and Tenant (Covenants) Act 1995 describes an AGA given where consent is given subject to a lawfully imposed condition that the tenant enters into it, but it does not itself say when a condition is lawful. For a qualifying lease, the parties can agree the condition in advance under section 19(1A) of the 1927 Act. That agreement is an authorised guarantee agreement (AGA) if the tenant guarantees the performance of the covenant by the assignee and the agreement meets the requirements of section 16(2), (4) and (5).

An outgoing tenant who signs an AGA stays liable for the assignee’s obligations. For what that means in practice, see our guide on the authorised guarantee agreement.

Is Stamp Duty Land Tax payable on an assignment?

On an ordinary assignment, any capital sum paid for the lease is chargeable, and the assignment is not treated as a new grant (HMRC SDLT manual, SDLTM17090, example 2). The assignee taking on the rent and the tenant’s other undertakings does not count as chargeable consideration (Finance Act 2003, Schedule 17A, paragraph 17).

The exception: if the original grant was exempt (for example group relief or charities relief), the first assignment that is not exempt under those reliefs is treated as the grant of a lease for the unexpired term, and any capital sum paid for the assignment is also chargeable (Finance Act 2003, Schedule 17A, paragraph 11; SDLTM17090).

Whether SDLT is due depends on the terms and the current rates, which this page does not cover. Check them on GOV.UK before completion. An independent solicitor you instruct can confirm the figure for your transaction.

Questions

Can a landlord refuse consent to an assignment of a business lease?
Yes, but only reasonably. Under section 1 of the Landlord and Tenant Act 1988, the landlord must decide within a reasonable time and give written reasons if it refuses.
Can the landlord charge me for giving consent?
It can require payment of a reasonable sum for its legal or other expenses under section 19(1)(a) of the Landlord and Tenant Act 1927. The sum must be reasonable.
Will I pay stamp duty when I take an assignment of a lease?
Normally SDLT is charged on any price paid for the assignment; taking on the rent is not chargeable consideration (Finance Act 2003, Schedule 17A, paragraph 17). The exception is where the original grant was exempt under certain reliefs, such as group or charities relief: the first non-exempt assignment is treated as the grant of a lease for the unexpired term (paragraph 11; HMRC manual SDLTM17090).
What is an authorised guarantee agreement?
An agreement by which the outgoing tenant guarantees the assignee’s performance of the lease covenants, as defined in section 16 of the Landlord and Tenant (Covenants) Act 1995. A landlord can require one as a condition of consent.
What is a qualifying lease for the agreed-grounds rules?
A new tenancy for the purposes of section 1 of the Landlord and Tenant (Covenants) Act 1995, other than a residential lease, under section 19(1E) of the Landlord and Tenant Act 1927.

Thinking of assigning your lease?

Tell us about the lease and the proposed assignee. An independent solicitor you instruct can check the consent terms, any guarantee and the SDLT position. Instrukt introduces independent SRA-regulated solicitors; it is not a law firm.

Speak to a solicitor

Sources

This guide is general information, not legal advice. Instrukt is not a law firm.