The mistakes below can each cost a London renter hundreds or thousands of pounds, and each comes with a check you can make at the right moment. Since the Renters’ Rights Act 2025 took effect on 1 May 2026, several of them have also become things a landlord or agent is not allowed to ask of you: rent before you sign, offers above the advertised rent, and months of rent up front (GOV.UK, Assured periodic tenancies: a guide for tenants). The figures in the examples use a one-bed flat in Lewisham at £1,457 a month, the borough’s average one-bed rent in August 2026 (ONS Price Index of Private Rents, from the London Rent Index on FTR London).
1. Paying before you have seen the home and signed
One kind of rental scam asks for money before you can view the home in person: a ‘deposit to secure it’ for a flat the scammer doesn’t own. Since 1 May 2026 a landlord or agent may not ask for or accept any rent before the tenancy agreement is signed (Tenant Fees Act 2019 s.5A), so a request for rent before signing is either a scam or a breach of the law. Before you sign, a landlord can take a holding deposit of up to one week’s rent, about £336 on the Lewisham flat, and it should come with the terms in writing.
View in person, or send someone you trust. Check that the person letting it is the owner or acts for them: if the property is registered, the owner’s name is on the title register at HM Land Registry (GOV.UK, get information about property and land). Never pay by bank transfer to a personal account because an advert says others are interested.
2. Offering more rent, or rent up front, to win the flat
Rental bidding has been banned in England since 1 May 2026. Adverts must state one rent, and landlords and agents must not ask for, encourage or accept offers above it, with fines of up to £7,000 per breach (GOV.UK, guide for landlords).
Offering six months’ rent up front, for example because you have no UK guarantor, is also off the table: between signing and moving in, the most a landlord may take is one month’s rent (GOV.UK, guide for landlords). On the Lewisham flat, that is £1,457 rather than £8,742 for six months. If you are asked to bid or pay more, you can report it to the council, even after you have signed. Our guide to tenant referencing covers the lawful alternatives, such as a guarantor.
3. Paying fees that are banned
Since 1 June 2019 the Tenant Fees Act has barred landlords and agents in England from charging tenants any payment not on its permitted list, which rules out fees for viewings, referencing, credit checks, inventories, contracts or ‘admin’ (Tenant Fees Act 2019, Schedule 1). They also can’t make you buy insurance, a guarantor service or a deposit replacement product as a condition of the tenancy (GOV.UK, Tenant Fees Act guidance). The payments allowed are rent, a capped deposit, a capped holding deposit, a fee of £50 for a change to the tenancy you ask for (more only if the landlord’s costs are higher), rent for the notice you didn’t give if you leave early, interest on rent more than 14 days late, lost-key costs, and bills you agree to pay. If you paid a banned fee, ask for it back in writing; your council’s trading standards or private housing team can investigate, and the First-tier Tribunal can order the landlord or agent to repay it.
4. Skipping the checks at the viewing
Ask to see three documents before you commit: the gas safety record (renewed every 12 months), the electrical safety report (at most five years old) and the energy performance certificate. A home rated F or G on its EPC can’t lawfully be let without a registered exemption (GOV.UK, minimum energy efficiency standard), and a low rating means higher heating bills. Look for damp and mould in corners, behind furniture and around windows, check that there is a working smoke alarm on each floor, and run the taps and shower. Our viewing checklist has the full list.
5. Signing without knowing which terms still count
Almost every private tenancy in England is now an assured periodic tenancy with no end date. An agreement, particularly one on a template written before May 2026, can still contain terms that no longer have effect: a fixed end date, a ‘break clause’, an automatic yearly rent rise, or a demand for rent before it is due. Read the whole agreement and the written statement of terms your landlord must give you before you agree. The statement must include the rent and when it is due, the amount of any deposit, and whether bills such as council tax are paid to the landlord (SI 2026/324); the name of the scheme protecting your deposit follows within 30 days of paying it. Ask about anything you don’t understand before you sign, not after.
6. Not recording the condition on the day you move in
If you dispute a deduction, the scheme’s adjudicator decides ‘on a balance of probabilities’ from the evidence both sides send (Deposit Protection Service). On the day you move in, photograph or film every room, including marks, stains and the insides of the oven and fridge, and check the inventory line by line. Email your photos and any corrections to the inventory to your landlord within a few days, so both of you hold a dated record. Take the same photographs when you leave. Our move-in day checklist sets out what to record.
7. Not checking that your deposit is protected
Your landlord must protect your deposit in one of three government-approved schemes (the Deposit Protection Service, MyDeposits or the Tenancy Deposit Scheme) within 30 days and give you the scheme details. If they don’t, a court must order them to pay you between one and three times the deposit (Housing Act 2004 s.214). On the Lewisham flat, the maximum five-week deposit is about £1,681, so the award would be between £1,681 and £5,043. Each scheme lets you check online whether your deposit is registered. See deposit protection schemes compared and how to get your full deposit back.
8. Forgetting council tax, or assuming it’s included
If you rent a whole flat or house, you normally pay council tax to the borough, on top of your rent; if you rent a room in a shared house let room by room, the landlord is usually liable. London bills vary a lot. For 2026/27 the average Band D bill in Lewisham is £2,237.33, against £1,028.21 in Wandsworth (MHCLG, council tax levels 2026 to 2027). If you live alone, you can claim 25% off: on a Lewisham Band D home that takes the bill from £2,237 to about £1,678 a year, but only if you apply. Ask for the council tax band before you sign, and see our guide to council tax and utilities.
9. Accepting a rent rise without checking it
Your landlord can raise the rent only once a year, not in the first year, and only by serving Form 4A at least two months before the new rent starts. An email saying ‘the rent goes up next month’ is not enough, and an automatic yearly increase written into the agreement no longer works. If you think the proposed rent is above the local market, you can apply to the First-tier Tribunal before the new rent starts, and it can’t set a rent higher than your landlord proposed (Housing Act 1988 s.14ZB). Compare your rent with the borough averages first; our guide to your rights as a London tenant explains the process.
10. Going without contents insurance
Your landlord’s insurance is for the property, not your belongings: ‘it’s up to you to insure your own belongings against theft and damage’ (Which?). A burst pipe from the flat upstairs or a burglary can mean replacing everything you own yourself. Contents insurance is your choice: a landlord or agent can’t make you buy it as a condition of renting. The price depends on what you insure, where you live and the cover you choose, so compare quotes for your postcode and check whether items you take out of the home, such as a laptop or bike, are covered.
11. Subletting or taking in a lodger without permission
Subletting all or part of your home without your landlord’s consent, including letting your room on a short-let site, breaks a term implied into every assured periodic tenancy (Housing Act 1988 s.15), and your agreement may also require consent before you take in a lodger. Breaking a term of the tenancy is a ground on which a landlord can ask the court for possession (Ground 12), although it is discretionary: the court decides whether eviction is reasonable (GOV.UK, grounds for possession). If the home is in a borough with property licensing, extra occupants can also put the landlord in breach of the licence. Ask first, in writing, and keep the reply.
12. Leaving without the right notice
To end an assured periodic tenancy you must give at least two months’ written notice, ending on a rent day or the day before, unless your agreement from before 1 May 2026 allowed less or your landlord agrees in writing to less. If you move out without enough notice, you can be charged the rent until the two months would have ended: £2,914 on the Lewisham flat. In a joint tenancy, one tenant’s notice will usually end the tenancy for everyone, so agree a plan with your flatmates before anyone gives notice (GOV.UK, guide for tenants).
What the mistakes cost on one London flat
| Mistake | What is at stake |
|---|---|
| Paying a scammer six months up front | £8,742, which a landlord couldn’t lawfully accept anyway |
| Leaving without two months’ notice | Up to £2,914 in rent |
| Not claiming the single-person discount on a Band D home | About £559 a year |
| No dated evidence of condition at move-in | Part or all of a £1,681 deposit |
| Not checking deposit protection | A court award of £1,681 to £5,043 you might not claim |
For the full monthly budget beyond the rent, see the hidden costs of renting in London.
Find your next home
You can browse flats to rent in Lewisham, or anywhere in London by borough, zone, bedrooms and property type, on FTR London and contact landlords directly, then check the asking rent against the London Rent Index. Landlords can list a home directly, stating one rent as the law now requires.
How we researched this: legal points checked against GOV.UK guidance and legislation.gov.uk on 24 September 2026; rents from the ONS Price Index of Private Rents (August 2026); council tax from MHCLG’s 2026 to 2027 release.
Correction, 24 September 2026: an earlier version of this article presented examples about named renters, such as ‘Sarah’ and ‘Emma’, as if they were real cases, and said the list came from analysing ‘hundreds of rental disasters’ and speaking with agents, landlords and tenants. The cases were invented and no such research was done; they have been replaced with worked scenarios using published figures. The earlier version also gave statistics without a source, such as ‘1 in 15 London renters’ losing money to scams and a claim that renting at the wrong time of year costs 15% more, and described listings on FTR London as ‘verified’.
It predated the Renters’ Rights Act: it assumed fixed-term tenancies and break clauses, said leaving early could cost the landlord’s full loss, and did not reflect the bans on rental bidding and rent in advance that took effect on 1 May 2026. It also said tenants rather than landlords always pay council tax, which is wrong for rooms let individually, and that a deposit must be returned within 10 days of moving out, when the 10 days run from agreeing the amount. The article has been rewritten to the law in force.