Prime London Property Glossary

An agreement in principle is a lender’s written indication of how much it is likely to lend, based on basic checks. It is not a formal mortgage offer, but it shows sellers and agents that a buyer’s finance is in hand.

Also called mortgage in principle, decision in principle·See also Proof of funds, Loan to value

An assured periodic tenancy is the standard private tenancy in England since 1 May 2026, when it replaced the assured shorthold tenancy. It has no fixed end date and runs until the tenant gives two months’ notice or the landlord ends it on a legal ground.

Also called rolling tenancy, periodic tenancy·See also Renters’ Rights Act 2025, Section 8 notice

The Annual Tax on Enveloped Dwellings is a yearly tax on UK residential property worth more than £500,000 that is owned by a company, a partnership with a corporate member or a collective investment scheme. Reliefs are available, for example for property let to unconnected tenants, but must be claimed each year.

Also called Annual Tax on Enveloped Dwellings·See also Capital Gains Tax, Inheritance Tax·Our ATED guide

Best and final is the request an estate agent makes when more than one buyer is interested: each is asked to submit their highest offer and final terms by a set time. It is less formal than sealed bids but works in a similar way.

Also called best and final offers·See also Sealed bids, Gazumping

A bridging loan is short-term finance, usually for up to 12 to 24 months, used to buy a property before another is sold or before long-term finance is in place. It can be arranged quickly but costs more than a mortgage.

Also called bridging finance·See also Property chain, Private bank mortgage

A buying agent is a property professional who acts only for the buyer, finding, assessing and negotiating the purchase of a home or investment. Unlike an estate agent, who is paid by the seller, a buying agent is paid by the buyer and has no interest in the sale going through at the highest price.

In prime London Many of the best prime London homes change hands privately, so a buying agent’s value lies as much in access to off-market property as in negotiation.

Also called buyer’s agent, property finder, acquisition agent·See also Estate agent, Off-market property, Retainer fee·Our buying service

Capital Gains Tax is charged on the profit made when selling a property that is not your main home, such as a second home or a rental. For individuals the rates on residential property are 18% and 24%, depending on income, and non-residents pay it on UK property too.

Also called CGT·See also Inheritance Tax, ATED·Our Capital Gains Tax guide

A chain-free buyer or seller does not depend on another sale or purchase to proceed. A chain-free property is one whose seller has no onward purchase, such as an empty home, an investment property or a probate sale.

Also called no onward chain·See also Property chain

Client Money Protection is insurance that letting and managing agents in England must hold, so that the rent, deposits and other money they hold for clients are protected if the agent goes out of business or misuses it.

Also called CMP·See also Tenancy deposit protection·Our property management service

Collective enfranchisement is the legal right of qualifying flat owners in a building to join together and buy the freehold from the landlord, whether or not the landlord wants to sell.

See also Share of freehold, Marriage value

Commonhold is a form of ownership in which each owner holds the freehold of their own flat and the building’s shared parts are owned and run by a company of all the owners. It exists in law but is rarely used, and the government plans to make it the standard for new flats.

See also Leasehold, Share of freehold

Comparable evidence is the record of recent sale prices for similar properties nearby, adjusted for size, condition, floor level and outside space. Valuers, lenders and buyers use it to judge whether an asking price is fair.

In prime London Prime London homes are rarely alike, so comparables need careful adjustment. Price per square foot is a starting point, not an answer.

Also called comps, comparables·See also Price per square foot, Mortgage valuation

Completion is the day the rest of the purchase price is paid, ownership passes to the buyer and the keys are handed over. It usually follows exchange by a few weeks, but can happen on the same day.

In prime London Stamp Duty must be reported and paid to HMRC within 14 days of completion, usually through the buyer’s solicitor.

See also Exchange of contracts, Stamp Duty Land Tax·Our Stamp Duty calculator

A conservation area is an area of special architectural or historic interest where the council applies extra planning controls, for example over demolition, trees and changes to the front of buildings.

In prime London Much of central London lies in conservation areas, which protects its character but limits alterations such as new windows, roof extensions and some basements.

See also Listed building, Searches

Conveyancing is the legal work of transferring ownership of a property from seller to buyer, from checking the title and contract to registering the new owner at HM Land Registry. It is carried out by a solicitor or licensed conveyancer.

In prime London For prime London homes, especially leasehold flats and listed houses, a solicitor who knows the area and the great estates is worth the extra cost.

See also Searches, Exchange of contracts, Completion

The deposit is the sum a buyer pays at exchange of contracts, traditionally 10% of the price, which commits them to the purchase. A buyer who then fails to complete can lose it. The word is also used for the share of the price paid from the buyer’s own money rather than a mortgage.

See also Exchange of contracts, Loan to value

An estate agent markets and sells property on behalf of the seller, who pays their fee, usually a percentage of the sale price. Their duty is to the seller, so their aim is the best price and terms for the seller rather than the buyer.

In prime London In prime London the same few agencies often handle the best homes, and many are shown quietly to trusted buyers and buying agents before, or instead of, being listed.

Also called selling agent, listing agent·See also Buying agent, Off-market property

Exchange of contracts is the point at which a property sale becomes legally binding. Buyer and seller swap signed contracts, the buyer pays a deposit, usually 10% of the price, and a completion date is fixed. Pulling out after exchange carries serious financial penalties.

Also called exchange·See also Completion, Deposit, Subject to contract·The buying process in ten steps

An exclusivity agreement is a written promise from a seller not to negotiate with other buyers for a set period, often a few weeks, while the buyer carries out surveys and legal work. Some are backed by a deposit from the buyer.

In prime London It is one of the few protections against gazumping before exchange and is worth asking for on a sought-after home.

Also called lock-out agreement·See also Gazumping, Under offer

First-time buyer relief lowers Stamp Duty for buyers who have never owned a home anywhere in the world and will live in the property. No tax is due on the first £300,000 and 5% is charged on the part up to £500,000. Above £500,000 the relief does not apply.

See also Stamp Duty Land Tax·Our Stamp Duty calculator

Freehold is outright ownership of a property and the land it stands on, with no time limit. Most houses in England are sold freehold.

In prime London Some prime London houses are long leaseholds held from one of the great estates, so a house is not always a freehold.

See also Leasehold, Share of freehold, The great estates·Leasehold property explained

A garden square is a private communal garden at the centre of a square of houses, open only to residents who hold a key and usually pay an annual garden levy.

In prime London Access to a garden square adds to value in parts of Belgravia, Kensington and Notting Hill where private outside space is scarce.

Also called communal garden·See also Conservation area

Gazumping is when a seller accepts a higher offer from another buyer after already agreeing a sale with you, but before contracts are exchanged. It is legal in England because an agreed sale is not binding until exchange.

In prime London The risk is highest in a rising market. An exclusivity agreement and a quick move to exchange are the usual protections.

See also Gazundering, Exclusivity agreement, Exchange of contracts

Gazundering is when a buyer lowers their offer shortly before exchange of contracts, knowing the seller may be reluctant to start again. Like gazumping, it is legal in England because nothing is binding until exchange.

In prime London A renegotiation backed by genuine survey findings is not the same thing, and is a normal part of buying.

See also Gazumping, RICS Level 3 survey

Ground rent is an annual payment a leaseholder makes to the freeholder under the lease. For most new residential leases granted since 30 June 2022 it is set at a peppercorn, effectively zero.

In prime London Older leases can carry ground rents that rise at intervals, so a solicitor should check the review terms before exchange.

See also Leasehold, Service charge

The higher rates are a 5% Stamp Duty surcharge on top of the standard rates. They apply when a buyer will own more than one home worth £40,000 or more, anywhere in the world, at the end of the day of purchase, and is not replacing their main home.

In prime London A buyer who replaces their main home but has not yet sold the old one can reclaim the surcharge if they sell it within three years.

Also called second home surcharge, 5% surcharge·See also Stamp Duty Land Tax, Non-resident surcharge·Our Stamp Duty calculator

Inheritance Tax is charged on the value of an estate above the tax-free allowance on death, usually at 40%. UK residential property is within its scope whoever owns it, including non-residents and overseas companies holding UK homes.

Also called IHT·See also Capital Gains Tax, ATED·Our Inheritance Tax guide

A lateral apartment is a flat laid out on a single floor across a wide footprint, often spanning two or more original buildings, rather than a conventional flat or a house arranged over several storeys.

In prime London Laterals are prized in prime London for combining house-sized space with the security and services of a portered building.

Also called lateral·See also Portered building

A lease extension adds years to the lease of a leasehold flat in return for a premium paid to the freeholder. Qualifying leaseholders have a legal right to add 90 years at a zero ground rent, and can now claim it as soon as they buy.

In prime London On a short lease the premium can be large, so the cost of extending should be priced into any offer.

See also Marriage value, Leasehold

Leasehold is ownership of a property for a fixed number of years under a lease from the freeholder. Most flats in England are leasehold. The leaseholder usually pays ground rent and a service charge, and the property’s value falls as the lease shortens.

In prime London Lease length matters a great deal in prime London. Below 80 years, extending becomes more expensive and some buyers and lenders will be put off.

See also Freehold, Lease extension, Ground rent, Service charge, Marriage value·Leasehold property explained

A listed building is officially protected for its architectural or historic importance and graded I, II* or II in England. Listed building consent is needed for most alterations, inside and out, and unauthorised works are a criminal offence.

In prime London Many prime London townhouses are Grade II listed. Buyers should check that past works had consent, because the liability passes to the new owner.

See also Conservation area, RICS Level 3 survey

Loan to value is the size of a mortgage as a percentage of the property’s value. A £1.5 million loan on a £2 million home is 75% loan to value. Lower loan-to-value mortgages usually come with better rates.

Also called LTV·See also Deposit, Mortgage valuation

Marriage value is the extra value released when a lease is extended or a freehold is bought, half of which the leaseholder must pay the freeholder when the lease has fewer than 80 years left. The Leasehold and Freehold Reform Act 2024 abolishes it, but that part of the Act is not yet in force.

In prime London Until it is, the 80-year mark still matters: a lease just above it is usually much cheaper to extend than one just below.

See also Lease extension, Leasehold

Material information is what estate agents must tell buyers, under consumer protection law, early enough for them to decide whether to view or buy. It includes the price, tenure, council tax band and lease details, and known issues such as flood risk or restrictions on use.

See also Leasehold, Searches

A mews house is a small house on a cobbled lane behind a grand terrace, originally built as stables and coach houses with living quarters above. Most have long since been converted into homes.

In prime London Mews houses in Belgravia, Kensington and Marylebone are sought after as quiet, private alternatives to a flat, but many are leasehold and have little room to extend.

Also called mews·See also Freehold, The great estates

A mortgage valuation is the lender’s own check of a property’s value, to confirm it is adequate security for the loan. It is brief, carried out for the lender’s benefit, and is not a survey of the property’s condition.

Also called lender’s valuation·See also RICS Level 3 survey, Loan to value

The non-resident surcharge is an extra 2% of Stamp Duty paid by buyers who are not UK resident for Stamp Duty purposes, broadly those who spent fewer than 183 days in the UK in the 12 months before buying. It applies on top of any other rates.

In prime London Buyers relocating to London may be able to reclaim it if they spend enough time in the UK in the year after the purchase, so timing matters.

Also called overseas buyer surcharge, 2% surcharge·See also Stamp Duty Land Tax, Higher rates for additional dwellings·Our Stamp Duty calculator

An off-market property is one for sale without being publicly advertised on portals such as Rightmove or Zoopla or in agents’ windows. Sellers choose this for privacy, to test the market quietly or to avoid a home looking stale if it does not sell quickly.

In prime London Discretion matters at the top of the market, so many prime London homes trade through agent networks and buying agents rather than listings. In 2025, 73% of the properties Black Brick sourced for clients were off-market.

Also called private sale, quiet sale, pocket listing·See also Buying agent, Estate agent·Accessing London’s off-market homes

A party wall agreement, or award, sets out how building work can go ahead when it affects a wall or boundary shared with a neighbour, or involves digging near their foundations. The Party Wall etc. Act 1996 requires the owner doing the work to serve notice first.

In prime London Basements and extensions are common in prime London, so buyers should ask about recent or planned party wall awards on both sides of a property.

Also called party wall award·See also Conservation area

A portered building is a block of flats with a porter or concierge on duty to handle deliveries, security and visitors. Some have a porter 24 hours a day; others staff the desk only during the day.

In prime London It matters to many international and lock-up-and-leave buyers, and is a large part of the service charge.

Also called concierge building·See also Service charge, Lateral apartment

Price per square foot is a property’s price divided by its internal floor area. It lets buyers compare homes of different sizes on a like-for-like basis and is the standard measure of value in the London market.

In prime London It varies sharply by street, building and floor, so two homes at the same figure can be very different propositions.

Also called £psf, psf·See also Comparable evidence

Prime Central London is the property industry’s name for the most expensive residential areas at the heart of the capital, generally taken to include Mayfair, Belgravia, Knightsbridge, Chelsea, Kensington, Marylebone, St John’s Wood, Notting Hill and Regent’s Park.

Also called PCL·See also Super-prime, The great estates·Prime Central London areas explained

A private bank mortgage is a home loan from a bank that serves wealthy clients, usually alongside investment or banking with it. Private banks look at a borrower’s whole financial position, so they can lend on complex income, international wealth and large loans.

See also Loan to value, Bridging loan

Proof of funds is evidence that a buyer can pay for a property, such as a bank statement, a letter from a private bank or a mortgage agreement in principle. Agents ask for it before putting an offer to a seller.

In prime London On a large purchase, a clear account of the source of funds prepared in advance makes an offer stronger and avoids delays later.

See also Source of funds, Agreement in principle

A property chain is a series of linked sales and purchases in which each buyer depends on selling their own home first. If one transaction falls through or is delayed, every sale above and below it can be held up.

In prime London Buyers with no chain, such as those buying with cash or relocating from abroad, are attractive to sellers and can often negotiate on price for that certainty.

See also Chain-free, Exchange of contracts

The Renters’ Rights Act 2025 reformed private renting in England. From 1 May 2026 it ended fixed-term and assured shorthold tenancies, turning them into rolling tenancies, and abolished Section 21 “no-fault” evictions. Tenants can leave with two months’ notice.

In prime London Landlords of prime London homes now need a legal ground to regain possession, such as selling or moving back in, so clear records and good letting advice matter more than before.

See also Assured periodic tenancy, Section 21 notice, Section 8 notice·Our Renters’ Rights Act guide

A restrictive covenant is a legal promise attached to land that limits how it can be used, for example banning business use, extra storeys or changes to the front of a building. It binds later owners as well as the original one.

In prime London The great estates have long controlled alterations through covenants and lease terms, so plans for a property should be checked against them before buying.

See also The great estates, Title register

A retainer is an upfront fee paid to a buying agent on appointment, to begin the search. It is usually deducted from the final fee when a purchase completes, and is normally non-refundable if the client stops the search.

In prime London Most prime London buying agents charge a retainer followed by a success fee on completion.

Also called engagement fee·See also Success fee, Buying agent·Buying agent fees explained

An RICS Level 3 survey is the most detailed inspection a buyer can commission. It covers the structure and condition of the property, describes defects and likely repairs, and is recommended for older, larger or altered homes.

In prime London Most prime London houses are period buildings, often extended or with basements, so a Level 3 survey is usually the right choice.

Also called building survey, full structural survey·See also Mortgage valuation, Gazundering

Sealed bids are a way of selling when several buyers are interested. Each submits a single written offer by a deadline without seeing the others, and the seller chooses, not always the highest, since chain, timing and certainty also count.

In prime London Sealed bids are common for the most sought-after prime London homes. A well-presented offer, with proof of funds and a clear timetable, can beat a higher but less certain one.

Also called informal tender·See also Best and final, Proof of funds

Searches are enquiries a buyer’s solicitor makes to the local council and other bodies about a property, covering planning, building control, roads, drainage and environmental risk. They can reveal issues that are not visible on a viewing.

In prime London In central London they often raise planning history, conservation area status and nearby basement or building works.

Also called local searches·See also Conveyancing, Conservation area

A Section 8 notice is how a landlord in England seeks possession of a rented home on one of the legal grounds in the Housing Act 1988, such as rent arrears, selling the property or moving back in. Since 1 May 2026 it is the only route for private landlords.

Also called grounds for possession·See also Section 21 notice, Assured periodic tenancy

A Section 21 notice was the “no-fault” notice a landlord in England could serve to end an assured shorthold tenancy without giving a reason. The Renters’ Rights Act abolished it from 1 May 2026.

Also called no-fault eviction·See also Section 8 notice, Renters’ Rights Act 2025

A service charge is what leaseholders pay towards running and maintaining their building, such as cleaning, insurance, repairs, lifts and porterage. It is set out in the lease and rises with the building’s costs.

In prime London In portered prime London buildings service charges can be substantial, so buyers should review several years of accounts and the reserve fund for planned major works.

See also Leasehold, Portered building·Service charges in prime developments

Share of freehold means the flat owners in a building jointly own its freehold, usually through a company, as well as each holding a lease on their own flat. It gives them control of the building and lets them extend their leases on agreed terms.

In prime London It is highly valued in prime London mansion blocks and converted houses, but buyers should check the company’s accounts, the lease lengths and any planned major works.

See also Leasehold, Freehold, Collective enfranchisement

Source of funds is where the money for a purchase is coming from, such as a named bank account. Source of wealth is how the buyer built their overall wealth, such as a business sale or employment. Agents, solicitors and lenders must check both under UK anti-money laundering rules.

In prime London International buyers and those buying through companies or trusts should expect detailed questions and documents, and preparing them early prevents delays before exchange.

Also called source of wealth, AML checks·See also Proof of funds, Conveyancing

Stamp Duty Land Tax is the tax a buyer pays on a purchase of property or land in England and Northern Ireland. It is charged in bands on the part of the price within each band, and must be paid within 14 days of completion.

In prime London On a £2 million home bought by a UK resident moving house, Stamp Duty is £153,750.

Also called SDLT, stamp duty·See also Higher rates for additional dwellings, Non-resident surcharge, First-time buyer relief·Our Stamp Duty calculator

Subject to contract means an agreement is not legally binding until formal contracts are exchanged. In England, offers, acceptances and correspondence about price are normally made on this basis.

Also called STC·See also Exchange of contracts, Under offer

A success fee is the main part of a buying agent’s charge, paid only when the purchase completes. It is normally a percentage of the purchase price, sometimes with a minimum, and any retainer already paid is usually deducted from it.

In prime London Because it is paid only on completion, it keeps the agent focused on securing the right property on the right terms.

Also called completion fee·See also Retainer fee, Buying agent·Buying agent fees explained

Super-prime is the very top of the property market. In London the term usually describes homes selling for £10 million or more.

In prime London Much of this market trades privately, and a single buyer’s requirements can narrow the realistic choice to a handful of homes.

See also Prime Central London, Off-market property

A landlord or agent in England who takes a deposit for an assured tenancy must protect it in a government-approved scheme within 30 days and give the tenant the required information. The deposit is capped at five weeks’ rent, or six weeks where the annual rent is £50,000 or more.

Also called deposit protection scheme·See also Client Money Protection, Renters’ Rights Act 2025·Our rental search service

The great estates are the historic landowners that still own large parts of central London, including Grosvenor in Mayfair and Belgravia, Cadogan in Chelsea, Howard de Walden and The Portman Estate in Marylebone. Many homes on their land are sold as long leaseholds.

In prime London Estate leases often carry rules on use, alterations and upkeep, and the estate’s consent may be needed before works.

Also called London estates·See also Leasehold, Restrictive covenant

The title register is the official record, kept by HM Land Registry, of who owns a property, what land it includes and the rights, restrictions and charges that affect it, such as mortgages and covenants.

Also called title deeds, Land Registry title·See also Restrictive covenant, Conveyancing

Under offer means a seller has accepted an offer but contracts have not yet been exchanged. The property may still be shown to other buyers and the sale can still fall through.

Also called sale agreed, sold subject to contract, SSTC·See also Subject to contract, Gazumping