At the start or end of a tenancy, a rent period may cover more or fewer days than the tenant occupies the property. A pro rata calculation divides rent in proportion to the relevant time. The first step is to agree which dates and rent period the calculation covers; do not assume every tenancy uses the same convention.
A simple daily-rate method
For a straightforward illustration, divide the rent for the period by the number of days in that period, then multiply by the days being charged. If monthly rent is £1,200 and the relevant month has 30 days, the illustrative daily amount is £40. Ten days would therefore equal £400 (£1,200 ÷ 30 × 10). In a 31-day month, using the same monthly rent, the result would differ if the parties use the actual calendar days. A 365-day annual method or another agreed contractual basis can produce a different figure. State the method, dates and arithmetic so both parties can check it.
For a tenancy starting part-way through a month, identify whether the first payment covers only the days to the next rent date or a different agreed period. For a tenancy ending part-way through a period, check the agreement, the date rent is due, any notice or surrender arrangements and the precise period being settled. A worked calculation is not, by itself, a decision about what the contract or law requires. If there is a dispute, ask a qualified adviser or a housing advice service to review the documents.
Rent in advance in England: a separate rule
Pro rata arithmetic should not be confused with the rules about when advance rent may be requested. For most new assured periodic private tenancies in England entered into from 1 May 2026, the landlord cannot ask for, encourage or accept rent before the tenancy agreement has been signed. During the signed agreement’s pre-tenancy period, the usual maximum request is one month’s rent for monthly payers, or up to 28 days for tenants paying more frequently than monthly. Government guidance describes exceptions, including specified social or supported housing and homelessness arrangements. Existing agreements and payments made before 1 May 2026 are treated differently. Check the current rules and the tenancy type before acting.
A clear record helps
Write down the period covered, start and end dates, rent amount, calculation basis and total. Show whether the final day is included, and explain how you treated a short or long month. Keep receipts and written agreement about any adjustment. If the dates or contractual terms are uncertain, pause before demanding or withholding money and seek independent advice. This guide is general information, not legal or financial advice, and the England-specific advance-rent rules do not apply automatically across the rest of the UK.