7 Mistakes London Landlords Make Self-Managing in 2026

Self-managing a rental property has always required time, patience, and a reasonable grasp of landlord law. In 2026, the bar is higher than it has ever been. The abolition of Section 21, the introduction of the Renters’ Rights Act, tighter enforcement powers for local councils, and a raft of compliance obligations that now carry five-figure penalties have fundamentally changed the risk profile of going it alone. For landlords in South West London, where rental values are high and tenant expectations are equally so, the cost of getting something wrong is not abstract. It is financial, immediate, and in some cases, career-ending for a landlord’s portfolio.

These are the seven mistakes that are catching self-managing London landlords out right now.

1. Failing to Comply with the Renters’ Rights Act

The Renters’ Rights Act came into force on 1 May 2026 and represents the most significant structural shift in private rented sector law in a generation. Section 21 no-fault evictions are abolished. All tenancies are now periodic assured tenancies. And the process for recovering possession is more procedurally demanding than it has ever been.

For self-managing landlords, the most immediately punishing mistake has been failing to issue the official government Renters’ Rights Act Information Sheet to existing tenants. The deadline for doing this was 31 May 2026. Landlords who missed it now face civil penalties of up to £7,000 per tenancy.

Two things catch landlords out here. First, the deadline itself, which many were simply unaware of. Second, the method of delivery: emailing tenants a link to the relevant government webpage is not compliant. The legislation requires that you either print the document and hand it over, or send the official PDF as a direct attachment to each named tenant.

Rent increases are equally tightly controlled under the new regime. Informal adjustments are not permitted. Any increase must happen no more than once per year, must reflect local market rates, and must follow the correct written notice procedure.

2. Misunderstanding HMO Licensing Obligations

Houses in multiple occupation carry their own licensing regime, and the penalties for non-compliance are severe: civil penalties of up to £40,000, and tenants can apply for a rent repayment order covering up to 24 months of rent paid during the unlicensed period.

The common assumption among self-managing landlords is that smaller properties are safe. Many London boroughs have introduced additional licensing schemes that apply to properties with just three or four occupants, well below the mandatory HMO threshold. Wandsworth, for example, introduced its selective licensing scheme in 2026 covering large parts of the borough. If your property sits within a designated area, a licence is required regardless of how straightforward the letting arrangement appears.

The stakes are particularly high now that Section 21 is gone. An unlicensed property can invalidate a Section 8 possession notice, which means a landlord who discovers mid-claim that their property required a licence they never obtained may be unable to recover the property at all until the position is regularised.

If you let property in South West London and are uncertain whether your property requires a licence, our Wandsworth licensing guide covers the 2026 scheme in detail.

3. Rushing Tenant Selection

Filling a void quickly is understandable. Every week a property sits empty costs money. But poor tenant selection consistently ranks among the most expensive mistakes a landlord can make, and under the current reforms, removing a problem tenant is a slower and more procedurally demanding process than it was before May 2026.

Around 16% of UK landlords have reported financial losses directly attributable to inadequate tenant vetting (NRLA, 2025). Skipping credit checks, accepting verbal references, or failing to verify employment status are the most common shortfalls.

Right to Rent checks are a separate legal obligation that self-managing landlords also frequently handle inconsistently. Every adult occupant must have their right to rent in the UK verified before the tenancy begins. Fines for failing to carry out checks correctly reach £20,000 per tenant. Most professional agents use digital verification systems that produce a clear audit trail; self-managing landlords often rely on manual processes that leave gaps.

4. Getting Deposit Protection Wrong

The rules here are straightforward, which makes it all the more frustrating when landlords fall foul of them. Any deposit taken for an assured tenancy must be protected in one of three government-approved schemes within 30 days of receipt. The prescribed information, covering which scheme holds the deposit, how disputes are resolved, and the conditions under which deductions may be made, must also be served on the tenant within the same window.

Failure to protect a deposit correctly can result in a penalty of up to three times the deposit amount. It can also prevent you from serving a valid possession notice, which, now that Section 21 is gone, means your only route to possession is through Section 8 grounds. If those grounds are not made out, or if your paperwork is defective, you have no fallback.

A landlord in Camberwell recently had a Section 8 claim rejected by the court because the gas safety certificate was not attached to the notice. The tenant remained in the property without paying rent for a further five months while the landlord restarted the process.

5. Letting Compliance Certificates Lapse

The compliance obligations sitting on a landlord in 2026 are not onerous in isolation, but they require consistent management. Self-managing landlords who treat compliance as an annual event rather than an ongoing process tend to find that certificates expire unnoticed, documentation goes missing, and enforcement action follows.

The core certificates that must be kept current are:

• Gas Safety Certificate: a Gas Safe registered engineer must carry out an annual inspection. The certificate must be issued to tenants within 28 days and retained for at least two years.
• Energy Performance Certificate: a valid EPC with a minimum E rating is required for all lettings unless the property is exempt. Future legislation is expected to tighten the minimum standard, and landlords who have not begun improving their properties are already behind the curve.
• Electrical Installation Condition Report (EICR): required every five years, or at change of tenancy. Remedial work identified in the report must be completed within 28 days.

Councils now have the power to request repair logs, maintenance invoices, and correspondence records as part of enforcement checks. The shift in 2026 is not just about doing the right thing; it is about being able to demonstrate that you have done it. Documentation is everything.

6. Mishandling Rent Increases

This is an area where the gap between informal landlord practice and legal requirement has widened sharply. Under the Renters’ Rights Act, rent can only be increased once every 12 months and must be proposed using the correct statutory notice. Tenants have the right to challenge any proposed increase at the First-tier Tribunal, which will assess whether the new rent reflects genuine local market rates.

Self-managing landlords who have historically raised rents informally, by letter, verbal agreement, or simply by mutual understanding at renewal, are now operating outside the law. A rent increase that does not follow the statutory procedure is unenforceable, and attempting to collect it could be treated as a prohibited payment.

Keeping a close eye on what comparable properties in your area are actually achieving is now a practical necessity, not just useful background knowledge. It is the evidence base for any increase you propose, and the tribunal will use it to assess whether your figure is reasonable.

7. Treating Self-Management as a Cost Saving

The final mistake is the one that underlies all the others: treating self-management primarily as a way to avoid agent fees, rather than as a management responsibility that requires active time, expertise, and systems.

For landlords with one property and a straightforward tenancy, self-management can work well if approached seriously. For those with more complex arrangements, HMO elements, older properties with higher maintenance demands, or tenancies in areas with selective licensing, the risk-adjusted cost calculation looks very different.

Professional letting agents carry professional indemnity insurance, use regulated deposit schemes, maintain compliance calendars, and have established relationships with qualified contractors. They also keep up with legislative changes as a core part of their work, rather than discovering them after a deadline has passed.

The risks of self-managing in the Putney rental market have been well-documented locally, and the pattern holds across South West London more broadly: the landlords facing enforcement action in 2026 are, in the majority of cases, those who were managing their own properties without professional support.

If you are weighing up whether self-management is still the right approach for your portfolio, Chartwell Residential can help you work through the compliance picture and what a managed service would actually cost against what you currently carry as risk. Speak to our lettings team directly through our contact page to arrange a conversation.