A rent review on a private tenancy in England now runs through a single statutory route, a Section 13 notice served on Form 4A. This glossary defines the terms that process uses in plain English, from the 52-week rule to service, and links each one to a fuller article where one exists.

The Renters' Rights Act 2025 rebuilt the vocabulary of rent reviews along with the rules. This glossary defines the terms letting agents in England meet in that process, in alphabetical order, each with a link to a fuller article where one exists. For the process end to end, start with the complete guide to rent reviews under the Act.

52-week rule to comparable evidence

52-week rule. Rent on a private assured tenancy can rise no more than once every 52 weeks, and never within the tenancy's first 52 weeks.[2][9] A 53-week adjustment stops review dates creeping earlier each year; the mechanics are in How often can a landlord increase rent?

Assured shorthold tenancy (AST). The default private tenancy type before 1 May 2026, now abolished. Existing ASTs converted automatically to periodic assured tenancies when the Act's tenancy reforms took effect.[4][7]

Assured tenancy. The standard private tenancy type in England under the Housing Act 1988, broadly a dwelling let as a separate dwelling to an individual who occupies it as their only or principal home.[1] Every private assured tenancy has been periodic since 1 May 2026.[7]

Backdating. What no longer happens to tribunal-determined rents. Where a tenant refers an increase, the old rent stays payable until the decision, and the new rent is never backdated to the start date on the notice.[5]

Comparable evidence. Evidence of what similar nearby properties, of similar size, features, and location, actually let for. Government guidance points challenging tenants to exactly this, which is why it belongs in your file before a notice goes out.[11] See What evidence supports a rent increase?

Determination to Form 4A

Determination. The First-tier Tribunal's decision on a referred rent. The tribunal determines the open market rent and cannot set a figure higher than the one on the notice.[3][5]

First-tier Tribunal (Property Chamber). The independent tribunal that decides rent referrals in England. A tenant's application must be received before the start date on the Section 13 notice.[11] The route is walked through in What happens if a tenant challenges a rent increase at tribunal?

Form 4A replaced Form 4, which now serves the social rented sector only.[10] The form itself is covered field by field in Form 4A: where to get it and how to complete it, and room-by-room lets in Section 13 and HMO room rents.

Open market rent to PIPR

The full picture, including what the tribunal can take into account, is in What is open market rent? For what the benchmark means for the size of an increase, see How much can a landlord increase rent?

Periodic tenancy. A tenancy that runs from rent period to rent period with no fixed end date. Since 1 May 2026 every private assured tenancy in England is periodic, and fixed terms are gone.[6][7]

Prescribed form. A form whose content is fixed by regulations rather than left to the sender. Section 13 notices in the private rented sector must be served on prescribed Form 4A, so serving the wrong form means no valid notice.[8][10]

Price Index of Private Rents (PIPR). The ONS's official measure of private rent price change. It tracks the whole stock of tenancies rather than just new lets, published down to local-authority level, so it shows average movement across an area, not the value of one property.[12] See What is PIPR, the ONS rent index?

Relevant low-cost tenancy to RHW12

Relevant low-cost tenancy. The social-housing carve-out. The amended Section 13 applies to any assured tenancy other than a relevant low-cost tenancy, which keeps social-sector rents outside the new process for now.[2]

Rent period. The recurring interval the rent is paid for, weekly or monthly for most tenancies. A Section 13 increase must take effect at the beginning of one: on a monthly tenancy running from the 20th, the new rent starts on a 20th.[2][9] Timing is covered in How much notice must a landlord give?

The statutory route prevails because the Act closed every other route to an increase; government guidance is explicit that rent increases by any other means are not permitted.[7] Why the clauses died, and what to do with agreements that still contain them, is in Are rent review clauses still valid?

Renters' Rights Act 2025. The Act that reshaped England's private rented sector. Its core tenancy reforms, including the reworked Section 13 process and prescribed Form 4A, took effect for the private rented sector on 1 May 2026.[4][6]

RHW12. Wales's equivalent form, and a reminder that this glossary stops at the border. A landlord in Wales varies the rent under a periodic standard contract by notice on form RHW12, with at least two months' notice and no more than once a year.[13][14] MarketRent covers England; the regimes are compared in England, Wales and Scotland rent increase rules

Section 13 notice and service

The notice runs on Form 4A, needs at least two months, and takes effect at the start of a rent period.[2][9] The whole notice is unpacked in What is a Section 13 notice?

Service. Getting the notice to the tenant in a way you can prove. Form 4A's own guidance is to use a method agreed in the tenancy agreement, hand the notice to the tenant, leave it at the tenant's address, or send it by registered post.[9] The options are compared in Ways to serve a Section 13 notice

Terms only get you so far; the dates and the evidence do the work. MarketRent applies these rules as part of the rent review workflow: it checks the 52-week rule, the rent-period start date, and the notice length, generates Form 4A, and keeps the record of service and evidence behind every review. For an indexed reference point before you propose a figure, try the Free Rent Indexation Tool.

This article is general information for letting agents in England, not legal advice.

Sources

  1. Housing Act 1988, section 1 (meaning of assured tenancy)
  2. Housing Act 1988, section 13 (as amended)
  3. Housing Act 1988, section 14 (as amended)
  4. Renters' Rights Act 2025 (c. 26)
  5. Renters' Rights Act 2025, section 7
  6. The Renters' Rights Act 2025 (Commencement No. 2 and Transitional and Saving Provisions) Regulations 2026 (SI 2026/421)
  7. Guide to the Renters' Rights Act, GOV.UK (MHCLG)
  8. The Assured Tenancies (Private Rented Sector) (Prescribed Forms and Transitional Provisions) (England) Regulations 2026 (SI 2026/354)
  9. Form 4A, landlord's notice proposing a new rent for assured tenancies in the private rented sector (GOV.UK)
  10. Assured tenancy forms, GOV.UK
  11. Apply for an open market rent determination, GOV.UK
  12. Price Index of Private Rents, quality and methodology information, ONS
  13. Renting Homes (Wales) Act 2016, section 123
  14. Notice of variation of rent, form RHW12, GOV.WALES