Assured Shorthold Tenancy Explained

An assured shorthold tenancy, or AST, was the default type of residential tenancy for private lettings in England and Wales from 1997 until the Renters' Rights Act reforms took effect in England on 1 May 2026. It gave a tenant a right to occupy for an agreed fixed term or on a rolling periodic basis, while giving the landlord a route, Section 21, to end the tenancy and regain possession without proving a specific reason once the fixed term ended.

That balance defined England's private rented sector for almost three decades. As of this update in August 2026, it has changed fundamentally in England: Section 21 has gone, fixed terms have gone, and every tenancy that used to be an AST is now an assured periodic tenancy under the reformed rules. This guide covers how ASTs worked historically, what fixed term and periodic tenancies actually meant in practice, and exactly how the reform moves landlords onto the new model. Wales and Scotland run separate tenancy frameworks and are not covered here.

AST basics

The assured shorthold tenancy was introduced by the Housing Act 1988 and became the default tenancy type for new private lettings in England and Wales from 28 February 1997, replacing the earlier assured tenancy as the standard model. Almost every private letting granted since then, where the tenant used the property as their only or main home and the landlord did not live in the property themselves, was an AST unless the parties specifically agreed otherwise or the rent or circumstances took it outside the regime altogether.

An AST gave the tenant security for the length of any fixed term, and specific statutory protections throughout, including deposit protection rules, the right to a copy of the gas safety certificate and the energy performance certificate, and (from 2015) protection from a Section 21 notice served in retaliation for a legitimate complaint about disrepair. What it did not give the tenant was indefinite security once the fixed term ended. That is the feature that has now changed for tenancies in England.

For most of its history, the AST worked reasonably well for both sides. Tenants got a clear, fixed period of guaranteed occupation and a known set of rights during that period, while landlords retained a straightforward, predictable route to regain possession, via Section 21, once that period had run its course, without needing to prove fault or build a legal case. That predictability is precisely why so much of the private rented sector, from letting agent paperwork to lender requirements to standard tenancy templates, was built around the AST-plus-Section-21 model for so long, and why the reform has meant a genuine, sector-wide change in how tenancies are drafted and managed, rather than a minor tweak to existing practice.

Who an AST applied to

Not every letting was automatically an AST, even during the decades when it was the default. The tenant had to occupy the property as their only or main home, and the landlord could not live in the same property as a resident landlord, since that arrangement falls under separate "excluded occupier" rules with far less tenant protection. Tenancies with a very high rent (above a set annual threshold) or where the landlord was a local authority, housing association or certain other social landlords also sat outside the standard AST regime, following their own separate rules. For the overwhelming majority of private landlords letting an ordinary house or flat to a family or individual tenant, though, the AST was the applicable framework by default, whether or not the paperwork used the term explicitly.

Fixed term and periodic

A typical AST began with a fixed term, commonly six or twelve months, during which neither party could normally end the tenancy early without the other's agreement or a serious breach. If neither party took action to end the tenancy when the fixed term expired, it did not simply lapse. Instead, it rolled on automatically as a "statutory periodic tenancy," continuing on the same terms as the original agreement but running week to week or month to month instead of for a fixed period, without either side having to sign anything new.

The practical importance of the fixed term versus periodic distinction was mostly about how and when a landlord could serve a Section 21 notice, and about the tenant's own flexibility to leave. Ending a tenancy during a fixed term generally required a break clause or mutual agreement, whereas a periodic tenancy could be ended by either side giving the appropriate notice at any point, without needing to wait for a term to expire. Many landlords used repeated fixed terms deliberately, renewing every six or twelve months, partly to keep this Section 21 mechanism straightforward and partly to allow a scheduled rent review at each renewal.

This is also where the phrase "assured shorthold" itself comes from: the tenancy was a form of assured tenancy, but a "shorthold" one, meaning the landlord's underlying right to get the property back at the end of a fixed term (or during a periodic tenancy, with notice) was built into the tenancy type from the start, rather than needing to be negotiated case by case. A full assured tenancy, the older and rarer alternative still seen occasionally on tenancies granted before 1997, gave the tenant considerably stronger long-term security than an AST, and did not carry the equivalent shorthold ground for possession, which is one reason the assured shorthold model became the near-universal choice for new lettings once it was introduced.

Reform trajectory

The Renters' Rights Act 2025 changed this model for tenancies in England from 1 May 2026. Fixed-term ASTs no longer exist for new tenancies; every private tenancy, new or continuing, is now an assured periodic tenancy, with no fixed term at all. A tenant can stay indefinitely, subject only to the landlord's ability to end the tenancy using a specific ground under Section 8, since Section 21 "no-fault" evictions were abolished at the same time. Our full guide to the Renters' Rights Act sets out the possession grounds, notice periods and rent increase rules that now apply in place of the old AST-and-Section 21 model, and our guide to tenancy agreement essentials covers what your paperwork should look like under the new rules.

Existing tenancies that were still running as ASTs on 1 May 2026 converted automatically to assured periodic tenancies on that date, by operation of law, without any new agreement needing to be signed. Landlords with tenancies already running did not need to do anything to trigger the change, though it is worth updating your own tenancy paperwork and records so they reflect a periodic arrangement rather than referring to a fixed term that no longer has any legal effect. A small number of tenancy types, notably purpose-built student accommodation covered by a recognised code, sit outside the assured tenancy regime entirely and were not affected by this transition.

The term "AST" itself is now largely a historical one for England, describing how the private rented sector worked for nearly thirty years rather than the tenancy type you will grant on a new letting today. It remains a useful reference point for understanding older tenancy agreements, older guidance, and how the sector arrived at its current rules, and it is still the relevant framework in Wales, which has its own separate occupation contract system, and in Scotland, which uses private residential tenancies under different legislation again.

How Property HQ helps

Property HQ's compliance register tracks each tenancy's key dates, from the original start date to notice periods and rent review dates, so you can see at a glance where a tenancy sits under the current rules rather than working from an old fixed-term end date that no longer determines anything.

Disclaimer

This guide reflects the position in England as understood in August 2026, following the Renters' Rights Act reforms. It is general information, not legal advice, and does not cover Wales or Scotland. Check GOV.UK or a qualified solicitor for guidance on a specific tenancy.