Form 4 served 30 April vs Form 4A served 1 May 2026: which regime applies to you

A rent increase notice that lands in your letterbox on 3 May 2026 but is dated 28 April 2026 is not what it looks like. The serving date — not the date typed at the top of the form — decides whether the old regime or the new regime applies to your case. And on this cliff-edge week, the difference is the single biggest tenant protection in the Renters' Rights Act 2025: whether the tribunal can set your rent higher than your landlord proposed.

This guide walks you through what "served" means in law, how to spot which regime applies to your notice, the worked examples that come up in this 30-April-to-1-May fortnight, and three response templates for the most common scenarios.

If you have a rent increase notice in front of you right now, run our free Section 13 check and we will tell you whether it is procedurally valid and whether you have grounds to challenge.

The two regimes at a glance

	Form 4 (old, served on or before 30 April 2026)	Form 4A (new, served on or after 1 May 2026)
Statutory form	GOV.UK Form 4	GOV.UK Form 4A
Notice period	1 month (weekly/fortnightly), 2 months (monthly), 6 months (annual)	2 months minimum, all frequencies
Tribunal can set rent higher than proposed	Yes — the historic deterrent	No — capped at the landlord's proposed figure
Tribunal decision backdated to notice date	Sometimes	Never — runs from decision date
12-month gap between increases	Yes	Yes (carries through)
Hardship deferral	Discretionary	Discretionary, more limited

The critical difference: under the old Form 4 regime, the tribunal could weigh the open-market rent and decide the proposed rent was actually too low — pushing you into a worse position than if you had not challenged. That deterrent is gone under Form 4A. Under the new regime, the worst the tribunal can do is confirm the landlord's proposed rent. There is no longer an upside for the landlord in an over-confident notice.

This is why the serving date you hand to the tribunal matters so much in this fortnight.

What "served" means in law

The serving date is the date the notice reaches you — not the date the landlord wrote at the top, not the date they posted it, not the date your agent typed it into a system.

The Housing Act 1988 and the Civil Procedure Rules treat service in three ways for a Section 13 notice:

1. By hand — served on the day the landlord or their agent physically gives it to you (or posts it through your letterbox).
2. First-class post — deemed served on the second working day after posting (this is the standard assumption).
3. Email or other electronic method — only if your tenancy agreement expressly authorises service by that route, and only at the email address listed there. If this clause is missing, electronic service is not valid.

A notice posted on Friday 1 May 2026 by first-class post is therefore deemed served on Tuesday 5 May 2026 (Saturday and Sunday are not working days, Monday 4 May is a bank holiday for the Early May bank holiday, so service runs to Tuesday 5 May). That notice is firmly in the new Form 4A regime — even if the form on the desk says "Form 4".

A notice handed to you in person on Wednesday 30 April 2026 at 5pm is served that day. If the landlord used Form 4, it is in the old regime. If the landlord used Form 4A, the form is wrong for the date and you have grounds to challenge it (see [[content/blog/2026-04-22-form-4a-minor-errors-tenant-invalidate]]).

The three serving-date scenarios you will see this fortnight

Scenario A — Form 4 served on or before 30 April 2026

The most common case for landlords trying to get one last increase under the old regime.

Example: Form 4 dated 15 April 2026, posted first-class on 28 April, deemed served on Wednesday 30 April. The notice specifies a new rent starting 1 July 2026.

What applies:

• Old Form 4 regime
• Two months' notice from the serving date (30 April → 30 June minimum) — start date of 1 July is valid for monthly rent
• Tribunal can set the rent higher than the proposed figure
• The 12-month minimum gap between increases applies
• If the tribunal rules, decision can be backdated to the start date of the proposed increase

Tenant strategy: Be very careful before applying to tribunal. Get strong comparable evidence ([[content/blog/2026-04-26-open-market-rent-tribunal-evidence-guide]]) and only escalate if your comparables are clearly below the proposed rent. The tribunal-can-go-higher risk is real here. Consider a negotiation letter first — many landlords would rather settle at slightly under the proposed rent than risk a tribunal finding that confirms it.

Scenario B — Form 4A served on or after 1 May 2026

The new regime. The launch-week wave.

Example: Form 4A dated 1 May 2026, posted first-class on 1 May, deemed served on Wednesday 6 May (Monday 4 May is the May bank holiday, then Tuesday and Wednesday are the two working days). The notice specifies a new rent starting 1 August 2026.

What applies:

• New Form 4A regime
• Two months' notice from the serving date (6 May → 6 July minimum) — start date of 1 August is valid for monthly rent
• Tribunal cannot set the rent higher than the proposed figure
• The 12-month minimum gap between increases applies
• Tribunal decision is not backdated — runs from the decision date

Tenant strategy: Challenging is much lower risk. Even if your evidence is mixed, the worst the tribunal can do is confirm the proposed rent. There is no longer a downside to applying for a hearing on the merits. Use [[content/blog/2026-04-25-first-week-rra-form-4a-arrives-tenant-playbook]] for the day-by-day actions.

Scenario C — Form 4 served on or after 1 May 2026 (procedural defect)

Some landlords or agents will use the wrong form by mistake. From 1 May 2026, only Form 4A is valid.

Example: Form 4 dated 1 May 2026, posted on 1 May, served Wednesday 6 May.

What applies:

• The notice is procedurally invalid — the wrong statutory form has been used.
• A landlord cannot rely on it to increase your rent.
• You do not need to apply to the tribunal — the notice cannot bite.

Tenant strategy: Send a written reply pointing to the defect and asking the landlord to withdraw and reissue using Form 4A. Do not pay the increased rent on the date the notice claims it starts. Keep paying the existing rent. If the landlord persists, file a tribunal application — a rejection on procedural grounds carries no risk under the new regime.

[!tip] If the form is wrong for the date, the notice is dead A Form 4 served on or after 1 May 2026 cannot increase your rent. Reply in writing pointing to the defect, keep paying the existing rent, and let the landlord re-serve under Form 4A if they want to push the increase forward. The 12-month minimum gap restarts from the date of the new (valid) notice.

The worked example: 28 April typed, 3 May posted, 5 May served

This is the most common cliff-edge case we will see in advice queries this fortnight.

Facts:

• Tenant pays rent monthly, on the 1st
• Landlord types the notice on 28 April 2026 (typed date "28-04-2026")
• Notice is on Form 4 (old form)
• Posted first-class on Sunday 3 May (royal mail collection Monday 4 May, but 4 May is the bank holiday — collection deferred to Tuesday 5 May)
• Deemed served on Thursday 7 May 2026 (second working day after collection)

Which regime applies? Form 4A regime. The serving date is 7 May 2026, after the 1 May 2026 cliff. The form on the desk says "Form 4" but the regime is decided by the serving date. Because the form is now wrong for the regime, the notice is procedurally invalid (Scenario C above).

Result: Notice cannot bite. Tenant replies in writing pointing to the defect. Landlord must reissue on Form 4A if they want to pursue the increase. The two-month notice clock would start fresh from the day the new Form 4A is served.

Common mistake: Tenants assume the typed date "28-04-2026" puts the notice into the old regime. It does not. The serving date — when the notice physically reaches the tenant — is what counts.

How to record the serving date (do this on day one)

You may need to prove the serving date at tribunal. The five-minute first-day audit:

1. Photograph the envelope if the notice arrived by post — capture both sides, including the postmark and any "first-class" indicia. Postmarks carry a date and confirm the posting day.
2. Photograph the notice itself — front and back, including any signature page.
3. Note the date and time you received it in writing — a one-line diary entry: "Notice arrived through letterbox at 09:15, Wednesday 6 May 2026."
4. Save the photographs to cloud storage (iCloud, Google Drive) so you have a timestamped backup.
5. Reply to the landlord by email or letter acknowledging receipt and stating the date you received it: "I write to acknowledge receipt of the rent increase notice dated 28 April 2026, which I received by post on the morning of 6 May 2026." This creates a written record of the date you say you received it.

If the notice is hand-delivered, ask the person delivering it to confirm the date. If you can record the moment on your phone (audio is fine, no need for video), do so. A door-camera time stamp is useful.

Three response templates

Template 1 — Acknowledge receipt and confirm serving date (Scenario A or B)

Dear [Landlord/Agent],

I write to acknowledge receipt of the rent increase notice dated [date on form], which I received by [post / hand / email] on [date received]. I am reviewing it and will respond in full within 14 days.

Could you confirm in writing the precise date on which the notice was sent (i.e. the postmark date), and confirm whether you treated this as service under the [Form 4 / Form 4A] regime?

Yours sincerely,

[Tenant name]

Template 2 — Reject Form 4 served on or after 1 May (Scenario C)

Dear [Landlord/Agent],

I write to confirm receipt of your rent increase notice dated [date on form], which I received on [date received].

The notice has been served using Form 4. From 1 May 2026, the prescribed form for a notice under section 13 of the Housing Act 1988 is Form 4A. As your notice was served (i.e. received by me) on [date received] which is on or after 1 May 2026, Form 4A is the correct form.

The notice is therefore procedurally invalid and cannot increase the rent payable under my tenancy. I will continue to pay the existing rent of £[amount] on the usual payment date.

If you wish to propose an increase, you may serve a fresh notice on Form 4A. The two-month notice period will run from the date that fresh notice is served on me.

Yours sincerely,

[Tenant name]

Template 3 — Confirm Form 4A regime applies and signal you may challenge (Scenario B)

Dear [Landlord/Agent],

I write to confirm receipt of your rent increase notice on Form 4A dated [date on form], which I received on [date received] and which proposes a new rent of £[proposed] from [start date].

I am reviewing the proposed rent against open-market evidence for the local area. I may apply to the First-tier Tribunal (Property Chamber) before the start date if I do not consider the proposed rent to be at the open-market level.

Under the Renters' Rights Act 2025, the tribunal cannot set a rent higher than your proposed figure of £[proposed]. I will write again within 21 days to confirm whether I intend to apply or to negotiate.

Yours sincerely,

[Tenant name]

What to do next

1. Photograph the envelope and notice today. Record the serving date in writing.
2. Run our free Section 13 check to confirm whether the notice is procedurally valid and which regime applies.
3. If Form 4 served before 1 May: decide whether to negotiate or apply to tribunal carefully — the tribunal-can-go-higher risk is still live. Build comparable evidence first.
4. If Form 4A served on or after 1 May: challenge confidently — the tribunal can no longer set rent higher than the proposed figure.
5. If Form 4 served on or after 1 May: reply in writing rejecting the notice as procedurally invalid; keep paying the existing rent.

Three days out from 1 May 2026, the difference between the two regimes is the single biggest tenant protection the Renters' Rights Act delivers. Get the serving date right and you have the right framework to act.

Key takeaways

• The serving date decides which regime applies — not the date typed on the form, not the date posted. First-class post is deemed served on the second working day after posting.
• Form 4 served on or before 30 April 2026 keeps the old regime: tribunal can set the rent higher than proposed, and decisions can be backdated.
• Form 4A served on or after 1 May 2026 activates the new regime: tribunal cannot set the rent above the proposed figure, and decisions are not backdated.
• Form 4 served on or after 1 May 2026 is procedurally invalid — reply in writing, keep paying the existing rent, let the landlord reissue on Form 4A if they want to proceed.
• Photograph the envelope and notice on day one, log the serving date in writing, and acknowledge receipt with the date you received it — this is the evidence the tribunal will use if there is a dispute.

FAQs

Q: My notice was dated 28 April but the postmark says 1 May. Which regime applies? A: Form 4A. The serving date is what counts, and a first-class letter posted on 1 May is deemed served on Tuesday 5 May (Monday 4 May is the May bank holiday). Tuesday 5 May is firmly inside the new regime. If the form was the old Form 4, it is procedurally invalid (Scenario C above) and cannot increase your rent.

Q: My landlord emailed the notice. Does that count as served? A: Only if your tenancy agreement specifically allows service by email and you have agreed to receive notices at that email address. Most older ASTs do not include such a clause. Without it, an emailed notice is not validly served — even if you have read the email. Check your tenancy agreement; if there is no electronic-service clause, reply pointing this out and refuse to treat the notice as served.

Q: The landlord says they served it by hand on 30 April but I was on holiday. When was it served? A: A notice handed to a person at the property is served on that day. A notice posted through a letterbox is served on the day the landlord can prove it went through the door — which usually means a witness, photo, or door-camera timestamp. If the landlord cannot prove the 30 April delivery and you have evidence (boarding pass, holiday booking) that you were not at the property, the notice may not be validly served until you returned. Keep the evidence.

Q: I received Form 4 by post on 5 May. Should I just pay the increased rent to keep things easy? A: No. Paying the proposed rent before the notice is procedurally valid risks creating an implied agreement to vary the rent — a contractual increase by conduct. Keep paying the existing rent. Reply in writing rejecting the notice (Template 2 above). If the landlord re-serves on Form 4A you will have a fresh two-month window to decide whether to challenge.

Q: If I challenge a Form 4 (old regime) notice, can the tribunal really set my rent higher than my landlord proposed? A: Yes. Under the old regime, the tribunal sets the rent at the open-market level it determines, even if that is higher than the landlord's proposed figure. This was historically the deterrent that kept tenants away from tribunal. From 1 May 2026 (Form 4A regime) that risk is gone. If you have a Form 4 served before 1 May, weigh your evidence carefully — only apply if your comparables are clearly below the proposed rent.

Need to confirm whether your notice is procedurally valid and which regime applies? Run our free check. It takes about two minutes and we will tell you the serving date analysis, the regime that applies, and whether you have grounds to challenge.