CP12 renewal rules: how the MOT-style 10–12 month window works

The single most common CP12 question is about timing: if I renew early, do I lose the remaining weeks on my current certificate? Since April 2018, the answer is no — as long as you renew inside the right window. Here is how the rule works and how to build a renewal habit that never lapses.

The MOT-style rule

A regulatory change in 2018 brought CP12 renewals in line with how car MOTs work:

• If the annual check is done in the final two months of the current certificate (months 10–12), the new certificate is dated 12 months from the old expiry date.
• Renew earlier than month 10 and the clock resets from the check date instead.

In practice: a certificate expiring 30 September can be renewed any time from 1 August, and the new one still runs to 30 September the following year. The expiry date becomes a stable anniversary — much easier to manage across a portfolio.

Why the window matters

Before 2018 landlords had a perverse incentive to renew at the last possible moment, because renewing early "wasted" the remaining validity. That is exactly how certificates lapse: everything is left to the final week, then the tenant is away, the engineer is booked up, or the reminder simply never arrives.

The 10–12 month window removes the trade-off. The rational strategy now is:

1. Book at the start of the window — week one of month 10.
2. Leave the rest of the window as slack for access problems, holidays, and rebooking.
3. Keep the anniversary date stable year after year.

The access problem

The most common reason renewals drift is tenant access. If a tenant refuses or repeatedly misses appointments, you cannot force entry — but you are expected to demonstrate reasonable steps:

• request access in writing, with dates
• offer alternatives and follow up
• keep a dated record of every attempt

If it comes to enforcement or possession proceedings, that trail is your evidence. A structured record of attempts (who was contacted, when, what was offered) is far more credible than a memory of phone calls.

What good renewal hygiene looks like

Whether you self-manage one flat or run a portfolio, the mechanics are the same:

| Habit | Why it works | | --- | --- | | Reminders at 8 and 4 weeks out | Two chances before the window closes, none dependent on memory | | One permanent link per property | The current certificate and its expiry date are always findable | | Book at the start of the window | The whole window becomes slack, not deadline | | Keep an access-attempt trail | Evidence of reasonable steps if a tenant blocks the check |

Engineers increasingly automate this: when the certificate is issued, the renewal reminders are scheduled in the same system, and the landlord gets a link that shows the property's compliance status all year round. If your engineer offers that — take it. If you are the engineer, offering it is what keeps the renewal coming back to you.

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