What Can Go Wrong Between Exchange and Completion

The Feeling That Something Might Go Wrong

You've exchanged. You're committed. You're waiting for completion. Then you get that nagging feeling: what if something goes wrong?

It usually doesn't. Most sales complete as planned without drama. But things do occasionally go sideways between exchange and completion. The good news is that most issues are solvable. Your conveyancer's job is to spot problems early and fix them before completion day arrives.

Financial Problems: The Mortgage Side

Your Lender Changes Terms

This is rare but it happens. Your mortgage offer might be conditional—it says the lender can withdraw if certain things don't happen between offer and completion. Things like: your employment changes, you miss a credit payment, your property valuation comes in much lower than expected.

If your employment changes (you leave your job, take unpaid leave, go part-time), you must tell your lender immediately. They might be okay with it. They might withdraw the offer. Let your conveyancer know if anything changes with your employment or finances. According to the FCA's mortgage conduct of business rules, lenders have specific requirements around employment verification. They'll contact your lender and sort it.

Property Valuation Issues

Your lender's valuation is done early in the process. If the property actually sells for less than the lender's valuation, there's no problem—you're paying what you agreed with the seller. But sometimes the lender's valuation comes in significantly lower than the purchase price. If the purchase price is £250,000 but the lender's valuation is £235,000, the lender might only release £235,000.

You'd then need an extra £15,000 from your own funds. If you don't have it, the sale can't complete. This is why you should have a buffer of cash available—more than just your deposit. It protects against this exact scenario.

If this happens, your options are:

• Renegotiate the purchase price with the seller
• Find extra funds from family, savings, or another source
• Withdraw from the purchase (and lose your deposit and incur costs)

It's rare and usually only happens if the market's moved significantly or there's something genuinely wrong with the property.

Your Own Funds Get Stuck

Sometimes buyers have promised to bring extra funds (beyond the lender's mortgage) at completion. These funds might be from savings, a family gift, or a personal loan. If you've said you'll bring £20,000 at completion and those funds get stuck (a transfer delays, a family member changes their mind, your loan falls through), completion can't happen.

Solution: Ensure your own funding is as solid as your mortgage. If you're relying on a personal loan, get formal approval weeks before completion. If you're relying on a family gift, get it in writing. If you're using savings, move the money to your conveyancer's account well before completion day.

Property Problems: Damage and Deterioration

Fire, Flood, or Vandalism

If the property is damaged before completion, the contract usually means you still have to complete. You're insured from exchange onwards. So if there's a fire, you complete the purchase, the insurance pays for rebuilding, and you own a property that needs repair. That's why buildings insurance must be confirmed at exchange. According to the Bank of England's CHAPS payment system documentation, completion funds are only released upon proof of insurance.

The practical solution: once you've had buildings insurance in place at exchange, stop worrying about this. Insurance exists for this exact reason. If damage occurs, your insurance claim covers it.

However, if damage is catastrophic (the house burns down, sinks into the ground), you might have legal grounds to withdraw. Your conveyancer would advise if this happened. It's vanishingly rare.

Subsidence, Damp, or Structural Issues

Sometimes issues aren't discovered until after exchange. A crack appears. Damp develops. You get a surveyor's report suggesting subsidence. What now?

If you discovered these issues before exchange, you'd probably have renegotiated or withdrawn. Now you're past exchange, so you're committed. Your options:

• Proceed as planned: Accept the issue and complete the purchase. You can deal with repairs after completion using your own money or insurance claims.
• Renegotiate: Contact the seller and ask for a price reduction or require repairs before completion. The seller might refuse, but it's worth asking. Your conveyancer can negotiate this.
• Seek specialist report: If the issue is uncertain (is it subsidence or just old cracks?), get a specialist report immediately. This might give you grounds to renegotiate or withdraw.
• Withdraw: You can technically withdraw from a purchase at any stage, but after exchange, you lose your deposit and face costs. Only do this for genuinely catastrophic issues.

Most buyers proceed. The issue is flagged, priced in (either by price reduction or insurance reserve), and dealt with after completion.

The Seller Doesn't Vacate

You're counting on getting the keys on completion day. But what if the seller is still in the house? They've moved some belongings but decided to stay a few more days or weeks.

This is a breach of contract. The seller must vacate by completion day. If they don't, your conveyancer can apply to the court for a possession order—forcing them to leave. But this takes time and delays completion.

The practical solution: your conveyancer will contact the seller's conveyancer immediately. Usually the seller cooperates and vacates within a few days. If they don't, the court application is made. You delay completion until they're out. It's not ideal but it's rare and it gets sorted.

Your own removals might be affected. If the seller's still in the property on completion day, you can't move in. Contact your removal company and delay your move by a few days.

Items Missing: Fixtures and Fittings

Agreed Items Removed

The contract specifies what's staying: fitted kitchen, curtain rails, garden shed, etc. But the seller takes them. You notice during the final walkthrough that the curtain rails are gone.

This is a breach of contract. The solution:

• Ask for replacement: Your conveyancer contacts the seller's conveyancer requesting the items be replaced. If the seller agrees, they can still be returned before completion.
• Retention of funds: At completion, your conveyancer holds back money (say, £500 if curtain rails cost £500 to replace). Once you have evidence the rails are reinstalled, the seller gets the money back.
• Compensation: The seller replaces the item or pays you compensation after completion. You then purchase new rails yourself.

Photograph everything during your final walkthrough. If something's missing, document it immediately. Don't wait until after completion.

Delays: Completion Pushed Back

The Lender Takes Longer

Your lender's taking longer than expected to process completion funds. This delays everything. You're waiting for funds. The seller's waiting. The estate agent's waiting.

Your conveyancer can contact the lender and chase them. Usually funds arrive the same day. Sometimes there's a genuine delay (the lender's system is down, there's a backlog, the funds need additional approval).

If completion delays by a day, you adjust your removals date. If it delays by more than a day, you might need temporary accommodation or extended rental of your old property.

The Seller's Conveyancer Can't Complete

The other side's conveyancer is having issues with their lender or the seller. Your conveyancer will keep you updated. In most cases it's a few-hour delay. Very occasionally it's a day or two.

There's not much you can do except wait. Keep your removal company informed. Keep yourself available. Your conveyancer will update you regularly.

You're Not Ready

Sometimes the buyer isn't ready. Your own funds haven't cleared. You've realized you need more time to arrange removals. You've discovered you need more money at completion.

If this is you, tell your conveyancer immediately. They can contact the seller's conveyancer and negotiate a delay. The seller might refuse, but if both parties agree, completion can be pushed back by days or weeks.

Ideally, avoid this. Have your finances confirmed weeks before exchange. Know exactly how much you're bringing and when it's available. Don't exchange if you're not ready.

Stamp Duty Land Tax: Calculation Errors

The SDLT Bill Is Wrong

SDLT (the tax on the purchase) is calculated based on the purchase price. Your conveyancer calculates it, files the return with HMRC, and pays it within 14 days of completion.

Occasionally the calculation is wrong. You were charged 2% when you should have been charged 5%. Or vice versa. This is usually caught by HMRC and corrected, with interest added if you underpaid. If you overpaid, HMRC refunds it (though it takes time).

Your conveyancer is responsible for getting this right. If they make a mistake, you can claim against them. But the most likely scenario is you get a correction notice from HMRC after completion. You pay the difference or claim your refund.

Solution: Check your completion statement with your conveyancer weeks before completion. Query any figures that look wrong. Ask them to explain the SDLT calculation. Don't wait until after completion.

Insurance Problems: Gaps in Coverage

Insurance Doesn't Start When You Thought

You arranged buildings insurance thinking it starts at exchange. But the insurance company needs additional documentation. Or the payment didn't go through. You discover on completion day that insurance hasn't actually started.

This is a problem because your lender won't release funds without insurance proof. Completion delays.

Solution: Check your insurance is actually active and confirmed weeks before exchange. Don't just assume it's in place. Ring the insurance company. Confirm the policy is active from the exchange date. Get written confirmation.

What To Do If Something Goes Wrong

Step 1: Tell your conveyancer immediately. Don't wait. Ring them. Email them. Any problem, however minor, needs to be flagged.

Step 2: Ask them what they'll do. Your conveyancer has dealt with most problems before. They'll have a solution. Listen to them.

Step 3: Keep communication open. Update your conveyancer on any changes. Tell them if funds are delayed. Tell them if you've found damage. Tell them if the seller's moving more slowly than expected.

Step 4: Keep perspective. Most issues are solvable. Most delays are a few hours or days. You'll still get your keys. Your house purchase will still complete.

Step 5: Have a buffer plan. If completion delays, can you extend your old rental? Can your removal company delay? Can you stay with family? Think about what you'd do if something did go wrong. Usually you won't need to, but it's calming to have a plan.

Most completions are straightforward. But knowing what can go wrong and how to handle it means you're prepared if anything does.

What's the most likely problem to occur between exchange and completion?

Delays. Lenders taking longer than expected to process funds, or the seller's conveyancer being slow to respond. Actual deal-breakers are rare. Most issues are just delays measured in hours or a day.

What if my lender changes the mortgage offer terms?

Contact them immediately to ask why. If it's minor (documentation), resolve it. If it's substantial (lower amount offered), you need to renegotiate the purchase price or find extra funds. This is why having confirmed funds weeks before matters.

Can I pull out after exchange if I change my mind?

Yes, but it costs you dearly. You lose your deposit (5–10% of purchase price), your survey costs, your conveyancing fees, and you face potential legal action from the seller for additional costs. Don't exchange unless you're certain.

What's the best way to handle stress if completion is delayed?

Stay calm and communicate with your conveyancer. They experience this regularly and have processes for handling delays. Keep your removal company and mortgage lender informed. Most delays resolve within 24 hours.

Should I have a backup plan if completion doesn't happen?

Yes. Know where you'd stay if you can't move into your new home on schedule. Can you extend your rental? Can you stay with family? Can your removal company reschedule? These contingencies reduce stress if unexpected delays occur.