Travelling with a large amount of cash might seem harmless—especially if it’s for a business deal, buying property, or helping family abroad. But UK law takes it seriously. If you’re entering or leaving the country with substantial cash, you must declare it to customs in advance.

Failing to do so can lead to much more than a warning. Border officers are authorised to seize the full amount of undeclared cash on the spot, even if the money is legally yours. The process that follows can be slow, stressful, and expensive if you’re not properly informed.

If your cash has already been taken, or you’re trying to avoid issues before your trip, this guide walks you through what happens—and how to protect yourself.

What Counts as “Cash”?

Under UK law, “cash” covers far more than notes and coins. Many travellers don’t realise that items commonly used for financial transactions can also fall under the legal definition—so it’s important to understand what you’re actually carrying.

Here’s what counts:

  • Coins and banknotes in any currency
  • Bearer bonds, cheques, and traveller’s cheques
  • Negotiable instruments, such as promissory notes or any documents that can be transferred or cashed without needing a bank account

Anything that can easily be exchanged for money or used to make a payment may need to be declared. So even if you’re not carrying stacks of banknotes, you could still be over the threshold without realising it.

When Do You Need to Declare?

If you’re travelling into or out of Great Britain with more than £10,000 in cash, you must declare it. The declaration can be made online up to 72 hours before you travel using the HMRC service or at the border by speaking to a customs officer.

The requirement applies to individuals, families, and groups—so if you carry more than the threshold between you, you’ll still need to declare it.

Missing this step can lead to seizure and potential penalties, regardless of your intent.

What Happens If You Don’t Declare?

Customs officers can take swift action if you haven’t submitted a declaration. They have the authority to seize the full amount immediately and hold it for up to 48 hours while they assess the situation.

If they believe the money could be linked to crime or tax evasion, they can apply to the court to keep it longer. This often leads to formal forfeiture proceedings. A civil penalty of up to £5,000 may also be imposed, usually deducted from the seized funds.

Importantly, the law allows officers to act on reasonable suspicion alone. They don’t need proof that the cash is tied to illegal activity. As a result, even travellers who are carrying funds lawfully can face serious consequences if they fail to declare the amount in advance. Being unaware of the rules isn’t considered a valid defence.

How Does the Seizure Process Work?

After a seizure, officers will give you a notice explaining why the money was taken. If they want to keep the cash longer than 48 hours, they must request permission from a magistrates’ court.

You’ll then have a chance to challenge the seizure through what’s known as forfeiture proceedings or apply to have your money returned through restoration.

The key to success is showing evidence that the cash was obtained legally and for a legitimate purpose. This includes:

  • Bank withdrawal records
  • Invoices or contracts
  • Business transaction documents
  • Travel receipts

Delays are common if documentation is incomplete or if the appeal isn’t handled correctly.

Can You Get the Money Back?

Yes—but it’s not automatic. You’ll need to provide clear evidence proving the money came from a legitimate source. You must also act within strict time limits, usually 30 days from the date of seizure.

If your application for restoration is denied or delayed, you may need to go to court to argue your case. This is where having legal advice can make a real difference.

Final Thoughts

Being stopped at the border with undeclared cash can feel overwhelming—but understanding the process helps you respond confidently. The best protection is prevention: declare large sums in advance, keep your paperwork in order, and act quickly if anything is seized.

And if your money has already been taken, don’t wait. Responding promptly and providing clear proof of ownership gives you the best chance of recovery.