Exchange of contracts and completion

Buying a home in England, Wales or Northern Ireland ends with two separate legal steps: exchange of contracts and completion. Exchange is the moment the buyer's and seller's legal representatives swap signed contracts and the buyer pays a deposit¹. From that point both sides are legally bound to complete the deal and can no longer change their minds without financial repercussions². Completion is the move-in date: your solicitor transfers the money and you collect the keys³.

The gap between the two is usually short but not instant. Which? puts completion at often around two weeks after exchange, though the date is flexible and agreed with the seller¹. Citizens Advice says it usually takes place about four weeks after exchange, although it can be earlier⁴. Either way, exchange is what makes the sale binding, and completion is what makes it yours.

Exchange and completion: two separate legal steps

Until contracts are exchanged, nothing in a house purchase in England, Wales or Northern Ireland is binding. Offers can be withdrawn, prices renegotiated and buyers can walk away. Exchange of contracts is the point where that changes: the buyer's and seller's legal representatives swap signed contracts, and the buyer pays the deposit¹. nidirect, the Northern Ireland government service, puts it plainly: "The exchange of the contracts to buy the property is the point where the sale is legally binding"⁶. From then on, both parties are legally bound to complete the deal and can no longer change their minds without financial repercussions².

The deposit paid at exchange is typically a percentage of the purchase price, agreed in advance, and it is held as the seller's protection against the buyer pulling out. Which?'s guide to selling describes exchange as "the moment when your buyer pays a deposit and things become legally binding"⁷. The exact completion date is written into the contracts at the same time, so both sides know when the money and keys must change hands.

Completion is the second step. On the agreed date, the buyer's solicitor sends the balance of the purchase money to the seller's solicitor, the seller releases the keys, and ownership transfers. Shelter Scotland describes it from the buyer's side: "On the move-in date, sometimes called the completion date, your solicitor will transfer the money and get the keys"³. After completion the buyer registers their ownership, pays any property tax due, and the seller hands over any guarantees and documents.

Scotland works differently. There is no exchange of contracts in the English sense: a Scottish offer, once accepted and concluded, is binding much earlier in the process, and the move-in date is called the date of entry. The practical insurance consequence is covered below.

Pulling out after exchange and delays to completion

Because exchange makes the deal binding, pulling out afterwards has consequences. A buyer who withdraws after exchange can lose the deposit they paid, and a seller who withdraws can face a claim for compensation from the buyer, who may have already spent money on surveys, legal fees and a mortgage offer. Before exchange, by contrast, either side can walk away, which is why gazumping and collapsed chains happen before that point and not after.

Delays to completion are a separate problem. If one side cannot complete on the agreed date, for example because a related sale has fallen through or funds have not arrived, the other side can be left in a difficult position. Citizens Advice describes a scheme called exchange with delayed completion, used in some situations where completion is put off for a few years: "you agree a sale price for your home with a buyer. When you exchange contracts, the buyer typically pays you an agreed deposit. However unlike a normal house sale, completion of the contract is delayed for a few years"⁸. Under such arrangements the buyer may take over paying the seller's mortgage, either directly or to the lender, and may also take over buildings insurance costs and agree to pay for repairs⁸.

These arrangements are unusual and carry real risks for both sides, and anyone offered one should take legal advice before signing. The general rule for a standard purchase is simpler: once you have exchanged, you are committed, so the time to resolve doubts about the price, the survey or the mortgage is before exchange, not after.

How long between exchange and completion

There is no fixed gap. Which? says completion often takes place around two weeks after exchange, but this is flexible and you can agree a convenient date with the seller¹. Citizens Advice gives a longer typical figure: completion usually takes place about four weeks after exchange of contracts, although it can be earlier⁴. The same guidance describes the legal work between the two steps as taking up to four weeks⁴.

The difference between the two figures reflects how varied real transactions are. A cash buyer and a seller with nowhere to move to can exchange and complete within days of each other. A buyer waiting on a chain of sales, a mortgage offer or a search result may need the longer window. The date is written into the contract at exchange, so it is fixed once exchanged, and missing it can trigger financial consequences.

Buildings insurance starts at exchange, not completion

This is the point that catches buyers out. In England, Wales and Northern Ireland, the buyer becomes responsible for the building at exchange, not completion, so buildings insurance must be in place from the day you exchange contracts. Which? is emphatic: "It's vital that you have buildings insurance in place on your new home from the day you exchange contracts - in fact, most mortgage providers will make this a condition of lending"¹. The Homeowners Alliance says the same: "You must insure your new property from the point you exchange contracts, which is the time you become liable for the building"².

The reason is risk. Between exchange and completion the buyer has paid a deposit and is legally committed, but does not yet live in the property. If the building burns down in that window, the buyer is still bound to complete the purchase, and a lender will not lend against a ruined building. Most mortgage lenders require buildings insurance from the date of exchange⁹, and most will require you to hold it as a condition of the mortgage¹⁰.

There is one exception in the guidance. Which? notes that if you are buying a new-build property, the insurance does not need to come into effect until the day of completion¹, because the builder remains responsible for the building until it is finished and handed over. Buyers of older homes get no such grace period.

Scotland: cover from the date of entry

Scotland's process has no exchange of contracts, so the insurance rule attaches to a different date. Shelter Scotland advises that "You'll usually need to get buildings insurance for the move-in date"³, which in Scotland is called the date of entry. Because a concluded Scottish contract is binding before the buyer takes ownership, the practical effect is similar: cover should be arranged so it is live by the day you move in.

Buyers using Scottish shared equity schemes should check the scheme rules as well as their lender's. The Open Market Shared Equity scheme guidance is published by the Scottish Government¹¹, and scheme homes carry their own conditions. The wider differences in the Scottish process, including when an offer becomes binding, are covered in the guide to buying a home in Scotland.

Insuring for the rebuild cost, not the price you paid

Buildings insurance is not based on what you paid for the property. It is based on what it would cost to completely rebuild the home, which is usually less than the sale price, because the land is not part of the rebuild¹². Which? explains that "Buildings insurance is based on this rebuild cost, not the market value"⁵.

Getting this figure wrong is expensive. The Financial Ombudsman Service sets out the position: "For example, if the rebuild cost of your home is £400,000 but you valued it at £200,000 in your insurance policy, you are 50% underinsured", and some insurers would only pay 50% of a claim, with the consumer paying the rest¹³. Which? warns in the same terms that if the figure on your policy is too low, your insurer may reduce any payout if you need to claim⁵.

Policies differ in how they set the figure. Your policy may be based on a specific buildings sum insured, a high standard limit, bedroom-rated cover, or unlimited cover⁵. Which? advises checking the rebuild cost at renewal, particularly if the figure has not changed for years, and after major changes such as an extension, loft conversion, structural work or major renovation⁵.

The ombudsman's case studies show how rebuild figures play out in real claims. In one, a homeowner's insurer told her it would actually cost £600,000 to rebuild her home, based on a loss adjuster's valuation¹⁴. In another, a loss adjuster estimated the cost of rebuilding a house at around £150,000 when it was only insured for £100,000¹⁵. In a third, an insurer argued that stabilisation work was "preventative, not restorative" and not strictly part of its liability, since its policy only covered the cost of repairs, before an investigation found otherwise¹⁶. A separate case turned on betterment: the insurer was only responsible for repairing what was already there, not adding to it¹⁷. The lesson from all of them is to keep the sum insured under review and to challenge valuations you do not accept.

What buildings insurance covers when you move in

A buildings policy covers the structure of the home itself and its permanent fixtures, and the scope is broader than many buyers expect. Citizens Advice notes that "Garages, sheds and fences are also covered, as well as the cost of replacing items such as pipes, cables and drains"⁹.

Weather damage is the core of most policies. Which? reports that buildings insurance should cover damage caused by hail, wind, rain, snow or ice, including broken roofs, frozen pipes, falling trees and loss of power¹⁸. Flood cover is usually included as standard with buildings insurance and is widely available, even for homes in high-risk areas¹⁹. A typical policy covers damage caused by floodwater entering the home from an external source, such as heavy rainfall, storms and high tide, or a river bursting its banks¹⁸.

The limits matter as much as the cover. Some insurers will not cover damage to patios, garden walls or driveways unless the main building is affected²⁰. Damage resulting from general wear and tear, such as water entering through a poorly maintained roof, is typically excluded from a standard policy¹⁸. Even where a cause is excluded, its consequences may not be: while chewed wires from rodents might not be covered, any fire they cause should be¹⁹.

Leasehold flats and new builds: who arranges the cover

If you are buying a leasehold flat, you usually do not arrange the buildings insurance yourself. Independent Age notes that "If it's a leasehold flat, the building may be insured by" the freeholder¹², with the cost passed to leaseholders through the service charge. Renters are in a similar position: if you are renting you probably do not need buildings cover, because the landlord is responsible for insuring the building, though you need your own cover for personal belongings²⁰.

Leaseholders have gained protections over how this insurance is arranged and paid for. The Leasehold and Freehold Reform Bill's provisions include replacing buildings insurance commissions for managing agents, landlords and freeholders with transparent administration fees²¹, and ensuring freeholders and developers are unable to escape their liabilities to fund building remediation work²¹. Where building safety costs are capped, the protections and caps are tied to the lease, so they automatically transfer to any future buyers of the leasehold property²².

Shared owners should check their lease too. Under the national model for shared ownership, the cost of repairs and maintenance is met by the landlord for the first 10 years after purchase of a new property, with some limits²³. In shared ownership flats, the cost of external repairs is divided between the flat owners if the reserve fund does not cover it²⁴. In Northern Ireland's House Sales Scheme, the leaseholder is responsible for maintenance and repairs regardless of how much equity they buy²⁵. New-build buyers have a further backstop: building warranties cover you if the builder is insolvent or commits fraud and does not complete the build, with the insurer refunding money, part-refunding, or arranging for the building to be finished²⁶.

Sellers between exchange and completion

Sellers have their own insurance to think about in the gap. You remain the owner until completion, so your buildings insurance should stay in place until the day the sale completes, not the day you exchange. Cancelling it early leaves a window in which a fire or flood would leave you with a damaged building you are still contractually able to sell, but at a reduced value, and a claim you cannot make.

The same principle applies in reverse to anything bought on hire purchase. National Debtline warns that "Terminating and ending your hire purchase agreement does not terminate a subsidiary insurance agreement. You will remain liable for it"²⁷, and that under hire purchase and conditional sale agreements, you do not own the goods until you have paid off the agreement²⁷. The general rule is that insurance follows responsibility, and responsibility follows ownership.

Excesses, exclusions and empty-property limits

Every policy has an excess, and some perils carry a much higher one. Subsidence cover is included in most buildings insurance policies but often comes with a higher excess, typically around £1,000²⁰.

Empty properties are a common trap, especially for buyers renovating before moving in, or sellers whose sale has completed before their purchase. Most insurers have a limit on how long a property can be left empty, typically 30 days, though some allow up to 60²⁰. Which? advises that if your home is going to be empty for more than 30 consecutive days, you may need a specialist unoccupied home insurance policy²⁰. Landlord insurance may cover an empty property for up to three months between tenants, but this varies¹⁰.

What buildings insurance costs

Costs vary widely by property type, and only limited average figures are published. One insurer review quotes an average combined home insurance premium of £288 for a detached bungalow, for quotes between 1 January and 1 July 2026¹⁰. Non-standard homes cost considerably more: data from October to December 2025 shows average combined policy costs ranging from £176 for non-listed buildings to £1,355 for thatched roof homes.

The cheapest way to buy is rarely the lender's own policy. Independent Age recommends shopping around for insurance rather than accepting the first quote¹², and a broker can help where a home is non-standard: the British Insurance Brokers' Association points to brokers' support at the time of a claim as well as their access to specialist markets²⁸.

Complaints about buildings insurance and where to get help

Buildings insurance generates a steady flow of complaints to the Financial Ombudsman Service. In the first quarter of 2026/27, 1,766 buildings insurance complaints were opened, and 33% were upheld in the consumer's favour²⁹. A year earlier, in Q1 2025/26, the figure was 1,668 complaints³⁰. The volume is not new: the ombudsman was already handling 3,447 buildings insurance complaints in 2008/09³¹.

The most common disputes are about claims. The ombudsman lists the recurring examples: the insurer arranged the repairs but has not fixed the damage; the repairs caused additional damage; the insurer says repair but the customer thinks replacement; the replacement is not the same as the lost item; the money offered is not enough; and dissatisfaction with the quality of the insurer-appointed builder's work³².

The process is fixed. Complain to the insurer first, setting out what went wrong. If the answer is not accepted, the complaint can go to the Financial Ombudsman Service, a free and easy-to-use complaints service²⁸. The ombudsman looks at whether the insurer acted fairly, including whether it gave proper guidance on the rebuild cost, as its case studies on valuations show¹⁴. Related products have their own complaint routes: 100 building guarantees complaints were opened in Q1 2026/27, alongside 550 home emergency insurance complaints²⁹.