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Pro rata rentfree, in seconds
Work out the part-month rent when a tenancy starts on a day that is not the rent day. Shows both the annual daily rate and the calendar-month rate, the days charged, and the date the first full month falls due.
Part-month rent for a tenancy that starts mid-month, on both of the conventions agreements use.
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The tenancy
- No law sets the formula. Your tenancy agreement decides which of the two below applies.
- The part period is charged for the days from move-in up to the day before rent day.
- Rent taken before the tenancy is entered into is a prohibited payment on an assured tenancy (Tenant Fees Act 2019, Schedule 1, paragraph 1(1A), from 1 May 2026).
Then £1,200 on 1 September 2026 and the same day each month after.
- Days charged
- 17
- Annual daily rate (£1200 × 12 ÷ 365)
- £39
- Part month on that rate
- £671
- Calendar-month rate (£1200 ÷ 31)
- £39
- Part month on that rate
- £658
- Difference between the two
- £13
The headline uses the annual daily rate, which is the more common wording and the one that gives the same daily figure in every month of the year. If your agreement divides the monthly rent by the days in that particular month, use the second figure. Whichever you use, write the calculation into the first rent demand so the tenant can check it.
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How part-month rent is worked out when a tenancy starts mid-month
Almost no tenancy starts on the day rent falls due. The tenant moves in on the 15th, rent is due on the 1st, and the first payment has to cover the days in between. That first figure is called pro rata rent, and there is no statute that says how to calculate it: the tenancy agreement decides, and different agreements decide differently.
Two conventions are in general use. The first takes the annual rent and divides by 365, so a daily rate that is the same in every month of the year. The second divides the monthly rent by the number of days in that particular month, so the daily rate is higher in February than in March. On a £1,200 rent the two can differ by around £8 for the same set of days.
Neither is wrong. What causes disputes is a first rent demand with a number on it and no working, because the tenant cannot reproduce it and assumes they have been overcharged. Whichever method your agreement uses, put the arithmetic on the demand: the daily rate, the number of days, and the date the first full month begins.
The days charged run from the move-in date up to the day before the next rent day. If somebody moves in on the rent day itself there is no part period at all, and the first payment is simply a full month.
One thing changed on 1 May 2026 and it catches people out. Under the Tenant Fees Act 2019 as amended by the Renters’ Rights Act 2025, rent that is payable before the tenancy is entered into is a prohibited payment on an assured tenancy. Taking the first month plus a part month up front, before the agreement is signed, is no longer a safe practice.
How to calculate pro rata rent for a mid-month move-in
Work out the part-month rent for a UK tenancy that starts on a day other than the rent day, using either the annual daily rate or the calendar-month rate.
- 1
Enter the monthly rent
Use the rent stated in the tenancy agreement, before any deductions.
- 2
Enter the move-in date
The date the tenancy begins, which is the first day rent is charged for.
- 3
Set the rent day
The day of the month rent falls due under the agreement. Most agreements use the 1st.
- 4
Read the days charged
The part period runs from the move-in date up to the day before the next rent day.
- 5
Pick the method your agreement uses
Annual daily rate (rent x 12 / 365) or calendar-month rate (rent / days in that month). Use the one your agreement specifies.
- 6
Show the working on the first demand
State the daily rate, the number of days and the date the first full month starts, so the tenant can check it.
Frequently asked questions
Is there a legal formula for pro rata rent in the UK?
No. No statute sets a method, so the tenancy agreement governs. The two conventions in general use are the annual daily rate (monthly rent x 12 / 365) and the calendar-month rate (monthly rent / days in that month). If the agreement is silent, the annual daily rate is the more common reading because it gives the same daily figure all year.
Should I use 365 or 366 in a leap year?
Most agreements say 365 and most agents use 365 regardless. The difference on a £1,200 monthly rent is under 11p a day. If your agreement specifies a divisor, use that one.
Can I ask for the part month and the first full month together, before the tenancy starts?
Be careful. Since 1 May 2026, rent payable before the tenancy is entered into is a prohibited payment on an assured tenancy under Schedule 1 paragraph 1(1A) of the Tenant Fees Act 2019, inserted by the Renters’ Rights Act 2025. Rent for a period after the tenancy has started is unaffected.
What if the tenant moves in on the rent day?
Then there is no part period. The first payment is a full month’s rent and every payment after it falls on the same day.
What if the rent day is the 31st?
A rent day later than the 28th does not exist in every month, which is why most agreements avoid it. Where one is used, it normally falls on the last day of a shorter month rather than rolling into the next one.
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