Fair rent calculator

A regulated tenancy is a protected or statutory tenancy under the Rent Act 1977, usually a private let that began before 15 January 1989. A rent officer at the Valuation Office Agency registers its rent, and the landlord cannot recover more than the rent registered (sections 44 and 45). When a new rent is applied for and one is already registered for the home, article 2 of the Rent Acts (Maximum Fair Rent) Order 1999 caps it: the existing registered rent, raised by the change in the Retail Prices Index since it was registered, plus 5%, or 7.5% on the first application since the Order came into force on 1 February 1999, then rounded up to the next 50p. The full guide, with what the tribunal decided in 2026, is how the maximum fair rent is worked out.

The Order writes it as MFR = LR × [1 + (x - y) ÷ y + P]. LR is the existing registered rent, the one on the register when the new rent was applied for; y is the RPI for the month it was registered; x is the RPI published in the month before the month the new rent is decided; and P is 0.05, or 0.075 on the first application since 1 February 1999. The index is the Office for National Statistics’ all items Retail Prices Index, which is published the month after the one it measures, so x is in effect the figure for two months before the decision: a rent decided in November 2026 takes the RPI published in October 2026, September 2026’s 422.1. If the rent officer has registered a new rent and it has gone to the tribunal on an objection, LR is still the rent registered before that application, not the rent officer’s figure, and y the RPI for the month that earlier rent was registered: the tribunal works the cap on those.

A flat registered at £725.00 a month in October 2024, not for the first time since 1999, with the new rent decided in November 2026: y is 390.7 and x is 422.1. (x - y) ÷ y is 0.080369; adding P makes 0.130369, so the multiplier is 1.130369 to six places, and £725.00 times the exact multiplier is £819.5172. Rounded up to the next 50p, the maximum is £820.00 a month. P is 0.05 because a rent registered in October 2024 came from an application made after 1 February 1999, so the next one cannot be the first since the Order, and the same goes for any rent registered from 2000 on. P is 0.075 only where no application for the home has been made since 1 February 1999. A weekly rent is worked on the weekly figure: £167.50 a week registered on the same dates comes to £189.3367, so £189.50 a week.

The Order rounds up, not to the nearest 50p (article 2(3)), and the Valuation Office Agency’s own page says the same: £819.5172 becomes £820.00, not £819.50. The calculator works the sum exactly and rounds once, at the end, because rounding along the way can move the answer by 50p. One tribunal sheet published in 2026 (LON/00AZ/F77/2026/0087) cut the multiplier, 1.146296, to three places: £725.00 × 1.146 is £830.85, which it rounded up to £831.00. Worked exactly on the sheet’s own figures, (x - y) ÷ y is 0.096296 (the sheet prints it as 0.097) and the sum is £831.0648, which the Order rounds up to £831.50.

Tribunal sheets do not all read y the same way. The Order asks for the published index for the month in which the rent was last registered, and the calculator takes that. Of three sheets published in 2026, one did the same (LON/00AG/F77/2026/0151: registered in August 2024, y 389.9), one took the RPI published in the month of registration, the previous month’s figure (LON/00AZ/F77/2026/0087: registered in February 2024, y 378.0, January 2024’s), and one the figure two months before, as for x (LON/00AY/F77/2026/0039: registered in December 2023, y 377.8, October 2023’s). On the example above the three readings give £820.00, £824.00 and £821.50. The calculator shows all three, so a sheet can be checked on the reading it used.

Three rules change the sum. A variable sum to be included in the registered rent under section 71(4), one that moves with the cost of services or of maintenance and repair works, is left out (article 2(5)). The tribunal’s sheets take the variable service charge off before the formula and add it to the result, and the calculator does the same: the variable sum in the existing registered rent comes off LR, and the variable sum in the new registration, which can differ, is added to the capped figure. Any other sum for services in the registered rent is part of LR and is capped with the rest. If repairs or improvements by the landlord, or a superior landlord, lift the newly decided rent at least 15% above the previous registered rent, the cap does not apply (article 2(7)). And if (x - y) ÷ y + P comes out below zero, the maximum is the existing registered rent (article 2(4)).

The maximum is a ceiling, not the rent. The rent officer values the home under section 70, leaving out personal circumstances and assuming that the people looking for similar homes in the locality do not substantially outnumber the homes available, and registers that figure or the maximum, whichever is lower. Landlord or tenant applies on form RR1. Neither can apply alone within two years of the date the last registration, or confirmation of the registered rent, took effect, unless the home, the terms or the circumstances have changed so much that the registered rent is no longer fair, but a landlord may apply in the last three months of those two years (section 67(3) to (5)), and the new rent then takes effect only when the two years end (section 72(3)). The Valuation Office Agency says a joint application may be accepted at any time. Either side can object in writing within 28 days of the rent officer’s notice; the First-tier Tribunal then values the home afresh, and it too cannot go above the maximum (Schedule 11, paragraphs 5A, 6, 9 and 9B).

Registering a higher rent does not raise it by itself. During the contractual term the rent is what the agreement says, up to the registered rent (section 44). On a statutory tenancy the higher rent is due from the date in a notice of increase in the prescribed form (sections 45(2)(b) and 49), and that date cannot be earlier than the date the registration took effect, or more than four weeks before the notice is served (section 45(3)). Anything charged above the registered rent cannot be recovered from the tenant, whatever the agreement says.

Sources, read on 26 October 2026: on legislation.gov.uk, the Rent Acts (Maximum Fair Rent) Order 1999 (article 2) and the Rent Act 1977 (section 18, section 44, section 45, section 49, section 67, section 70, section 71, section 72 and Schedule 11); the Office for National Statistics’ Retail Prices Index, series CHAW, as released on 21 October 2026; and on GOV.UK, Fair rents, Fair rent forms, the register of fair rents and residential property tribunal decisions, where the three sheets above are published.