⚠️Renters Rights Act — 1 May 2026.See what changes →

⚠️Renters Rights Act — 1 May 2026.See what changes →

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Section 219 min read1 March 2026

7 Reasons Your Section 21 Notice Will Be Invalid in 2026

One compliance mistake can make an entire Section 21 eviction notice unenforceable. Here are the 7 most common reasons Section 21 notices fail — and how to avoid them.

Why Section 21 Notices Fail

Section 21 allows landlords to regain possession of a property without needing to prove fault. But it has strict procedural requirements, and courts take non-compliance seriously. If any precondition is not met, the judge will simply strike out the possession claim — leaving you to start from scratch.

Here are the 7 most common reasons Section 21 notices are declared invalid.

Mistake 1: Lapsed Gas Safety Certificate

Your Gas Safety Certificate (CP12) must be in date at the time you serve the notice and throughout the possession claim. If your CP12 expired even one day before you served the notice, the Section 21 is invalid.

The fix: Never let your Gas Safety Certificate lapse. LetCompliance sends reminders before expiry so this never catches you out.

Mistake 2: Deposit Not Protected (or Prescribed Information Not Served)

This is the most common cause of invalid Section 21 notices. Your tenant's deposit must be:

  • Protected in DPS, TDS or mydeposits within 30 days of receipt
  • Subject to Prescribed Information served within 30 days
  • If either step was missed, or if the deposit was re-protected but the Prescribed Information wasn't re-served on renewal, your Section 21 is invalid.

    Important: Even if you protect the deposit late, the Section 21 remains invalid for that specific tenancy period unless you first return the deposit and negotiate afresh.

    Mistake 3: EPC Not Provided to Tenant

    The tenant must have received a copy of a valid EPC before the tenancy started. If there's no record that you provided it, or if the EPC was expired when you provided it, the Section 21 is at risk.

    The fix: Keep a signed receipt or email evidence that you provided the EPC. Store a copy in LetCompliance.

    Mistake 4: EICR Not Valid or Not Provided

    Since 2021, your EICR must be valid and provided to the tenant. An expired EICR or one where there's no evidence the tenant received it can invalidate your Section 21.

    The fix: Ensure your EICR is within the 5-year cycle and that you have a record of providing it to the tenant.

    Mistake 5: Wrong Form Used

    Section 21 notices must be served on Form 6A — the prescribed government form. Using an old or unofficial form, or writing your own letter, will likely result in the notice being invalid.

    Form 6A is available from GOV.UK. Always use the current version. LetCompliance generates a correctly formatted Section 21 notice pre-filled with your property and tenancy details.

    Mistake 6: Served Too Early or Too Late

  • Too early: You cannot serve Section 21 within the first 4 months of a fixed term tenancy.
  • Too late: A Section 21 notice expires 6 months after it's served. If your tenant doesn't leave and you haven't started possession proceedings within 6 months, the notice expires and you must start again.
  • Also: you must give at least 2 months' notice. You cannot specify an end date that is less than 2 months from the date of service.

    Mistake 7: How to Rent Guide Not Provided

    The current government How to Rent guide must have been provided to the tenant at the start of the tenancy. If it wasn't, or if you provided an outdated version, your Section 21 may be invalid.

    The government updates this guide periodically. Always download the current version from GOV.UK and provide it at move-in.

    Pro tip: Send it by email with a read receipt, or include it as an attachment to the tenancy agreement signing — so you have clear evidence of delivery.

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    LetCompliance checks all 7 preconditions before generating a Section 21 notice — so you'll never unknowingly serve an invalid notice. Get started →

    Track all this automatically with LetCompliance

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