RPI (Retail Price Index) Rent Review in Commercial Leases

When you're entering into a commercial lease, the way future rent increases are structured is just as important as the starting rent itself. One of the most common rent review methods in the UK is the RPI rent review, which ties rent to the Retail Price Index (RPI), a measure of inflation published by the Office for National Statistics (ONS).

An RPI rent review is a mechanism that automatically adjusts rent in line with inflation. The calculation is straightforward: if RPI has gone up by 5% since the last review, the rent also increases by 5%.

For landlords, this ensures rental income keeps pace with inflation. For tenants, it offers predictability and avoids protracted disputes about market value. But during times of economic volatility, it can also mean sudden, steep increases in rent.

In this guide, we'll break down exactly how RPI rent reviews work, what to watch out for, and what the upcoming phasing out of RPI means for the future of commercial lease agreements.

Table of Contents

What is an RPI Rent Review in a Commercial Lease?

An RPI rent review in a commercial lease is a method of adjusting rent based on the Retail Price Index (RPI), which tracks inflation in the UK. An inflation index is published every month by the Office for National Statistics (ONS).

Unlike open market rent reviews, where rent is reassessed based on comparable properties (often leading to negotiation or disputes), RPI reviews are formula-based and transparent. Both landlords and tenants know in advance how the rent will be adjusted.

How Does an RPI Rent Increase Work?

With an RPI rent increase, the rent is adjusted according to the percentage change in the RPI published by the Office for National Statistics. For example, if the RPI rises by 4% during the review period, the rent also increases by 4%. Some leases include caps and collars to prevent excessive rent rises or ensure a minimum increase, giving both landlords and tenants more certainty.

Example of an RPI Rent Review in Practice

Imagine a retailer signs a 10-year lease with rent set at £40,000 per year. The lease has an RPI rent review every three years, with a cap of 5% and a collar of 2%.

• Year 1–3: Rent = £40,000
• Year 3: RPI has increased by 7%. Because of the 5% cap, the rent only rises by 5% → £42,000
• Year 6: RPI has fallen by 1%. Because of the 2% collar, the rent still rises by 2% → £42,840
• Year 9: RPI has increased by 3%. Rent rises accordingly → £44,125

This example shows how caps and collars protect both parties while keeping rent aligned with inflation.

Key Lease Terms to Check in RPI Rent Reviews

When reviewing a lease with an RPI rent clause, there are several important points to look out for.

Review Frequency

The lease should state how often the rent review takes place, whether annually, every three years, or at another interval. More frequent reviews mean rent keeps pace with inflation more closely, but they can also lead to higher cumulative costs for tenants.

Version of RPI

There are different versions of the Retail Price Index, so the lease should be clear about which one is being used for the calculation. This ensures transparency and consistency throughout the lease term.

Caps and Collars

To protect both landlords and tenants, leases often include a cap (maximum increase) or collar (minimum increase). This prevents rent from skyrocketing in times of high inflation or stagnating in periods of low inflation. For example, a clause might state that the rent cannot increase by more than 5% or fall below 1% at each review.

Compounding

Some leases apply rent increases on a compounded basis, meaning each year's increase builds on the previous one. Tenants should check whether the rent increase is compounded annually or calculated only at specific review dates. Compounding can have a significant effect on long-term affordability.

Considerations for Tenants Facing an RPI Rent Review

For tenants, agreeing to an RPI-linked rent review requires careful thought.

Uncertainty and Risk

While the formula is transparent, the actual rent increase depends on inflation. During times of economic volatility, tenants may face much higher rent than expected. This uncertainty can make long-term budgeting more difficult.

Alternatives to RPI Rent Reviews

Instead of linking rent to RPI, tenants may negotiate for alternatives such as:

• CPI rent review (Consumer Price Index), which tends to rise more slowly than RPI.
• Open market rent review, where rent is aligned with current market conditions.
• Fixed rent increases, offering stability with pre-agreed increments.

Each option has pros and cons, but the key is negotiating terms that reflect both business needs and the market environment.

Professional Legal Advice

Because the wording of rent review clauses can significantly impact financial obligations, it is always advisable for tenants to seek advice from a commercial lease solicitor. A solicitor can explain the risks, negotiate fair caps and collars, and ensure that the rent review mechanism is clear and enforceable.

Is an RPI Rent Review Fair for Tenants?

An RPI rent review clause can be fair because it uses a transparent formula rather than subjective market valuations. However, during times of high inflation, tenants may find their rent rising faster than expected. Many tenants negotiate caps and collars in leases or explore alternatives like CPI rent reviews or fixed rent increases to make costs more predictable.

Can Tenants Negotiate RPI Rent Review Terms?

Yes, tenants can negotiate the terms of an RPI rent review in a commercial lease. This might include the frequency of reviews, which version of RPI is used, or setting caps to limit maximum increases. Some tenants also prefer fixed rent increases or open market rent reviews, depending on their long-term financial strategy. Seeking advice from a commercial lease solicitor is essential to secure fair and manageable terms.

What Happens to Existing Leases When RPI is Phased Out?

Since RPI will be phased out by 2030, existing leases that reference RPI may need updating or interpretation. In most cases, RPI will be aligned with CPI, which tends to result in smaller increases. Landlords and tenants should review their contracts and seek legal advice to understand how this change could affect their rent review clauses in the future.

Conclusion: Protecting Your Interests in RPI Rent Reviews

An RPI rent review provides a clear, formula-based way of linking commercial lease rent to inflation. While it reduces disputes, it also exposes tenants to the risk of sharp rent increases during high inflation. With RPI being phased out in favour of CPI by 2030, businesses entering into leases today need to consider whether this mechanism remains the best option.

Both landlords and tenants should carefully check lease terms, negotiate fair caps and collars, and seek expert advice before committing to an index-linked rent review. With the right legal guidance, you can ensure that your lease strikes a balance between predictability and fairness.

Need advice on your RPI rent review? Contact our commercial lease solicitors today at 0203 959 7755 for advice on RPI clauses, caps, and collars.