Wales Notice Period Calculation: Clear Days and Expiry Dates

One miscounted day can invalidate a possession notice in Wales. The Renting Homes (Wales) Act 2016 uses a clear days rule that differs from how many landlords instinctively count, and the prescribed forms require you to enter specific dates. This post walks through the calculation for each notice route.

The Clear Days Rule

Under RHWA 2016, the day you serve or deliver the notice does not count as Day 1 of the notice period. It's Day 0. The statutory period begins on the next calendar day.

This means the possession date you enter on the form must be calculated from the day after service, not from the service date itself. Courts apply this strictly.

Section 173 (Form RHW16) — Six Calendar Months

This is the standard no-fault notice for periodic contracts.

• Service date: 10 October 2026 (Day 0)
• Notice period starts: 11 October 2026
• Duration: Six calendar months
• Earliest possession date: 11 April 2027
• Court claim window opens: 11 April 2027
• Court claim window closes: 11 June 2027 (two months after expiry)

If you write 10 April 2027 on the form instead of 11 April, the notice is one day short. An error that small can be fatal if challenged.

Section 182 (Form RHW20) — Serious Rent Arrears, 14 Calendar Days

• Service date: 10 October 2026 (Day 0)
• Notice period starts: 11 October 2026
• Duration: 14 calendar days
• Earliest possession date: 25 October 2026
• Court claim window: Starts 14 days after service, closes six months after service (10 April 2027)

The arrears must still meet the statutory threshold on the hearing date. If the contract-holder pays down to below two months' rent before the hearing, the mandatory ground falls away.

Section 157/181 (Form RHW23) — Breach, One Calendar Month

• Service date: 10 October 2026 (Day 0)
• Notice period starts: 11 October 2026
• Duration: One calendar month
• Earliest possession date: 11 November 2026
• Court claim window: Closes six months after service (10 April 2027)

For anti-social behaviour or prohibited conduct, there is no notice period at all — the landlord can file a court claim immediately on the day of service.

Section 194 (Form RHW24) — Break Clause, Six Months

This applies to fixed-term contracts of two years or more. The calculation mirrors section 173:

• Six calendar months from the day after service
• Cannot be exercised in the first 18 months of occupation
• Two-month court claim window from the notice expiry date

What "Calendar Months" Means

Six calendar months from 11 October means 11 April — not "180 days" or "26 weeks." Calendar months follow the month boundaries. For example, if you serve on 31 August, the period starts on 1 September and runs to 1 March; count six calendar months from that date, not a fixed number of days.

The Two-Month Court Window

For no-fault notices (RHW16, RHW17, RHW22, RHW24), the court claim window is exactly two calendar months starting from the notice expiry date. For fault-based notices (RHW20, RHW23), the window is six months from the date of service.

Missing the court window means the notice is spent. For section 173 specifically, you then face an additional six-month bar before you can serve a new notice.

Practical Tips

Write out the calculation longhand before entering dates on the form. Double-check the calendar — months vary in length. For postal service, factor in the deemed service date: the day after posting for first class, two business days after posting for second class.

Keep a written record of your calculation alongside the served notice and proof of service. If the contract-holder or their solicitor challenges the dates, you want the working to hand.

For printable notice period calculators and a full step-by-step process guide, see our Ending an Occupation Contract in Wales guide.

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