Martin Lewis Debit Card Warning: Why Using Your Debit Card Could Cost More Than You Think?

Martin Lewis has warned UK debit card users that spending while overdrawn can be more expensive than borrowing on a credit card. With some high-street overdrafts charging around 40% annual interest, a debit card is not always the cheaper or safer option.

The warning challenges the common belief that debit cards automatically prevent debt while credit cards create it. In reality, the difference depends on the account balance, borrowing costs, repayment behaviour and protection available if a purchase goes wrong.

Our review of UK consumer-protection guidance, banking costs and practical spending scenarios highlights another important concern: choosing Pay by Bank at an online checkout can mean losing the chargeback or Section 75 protections normally associated with card payments.

For households, freelancers and small business owners managing tight budgets, understanding these differences can help prevent unnecessary interest charges and expensive purchasing mistakes.

What Is Martin Lewis’s Debit Card Warning in 2026?

The Martin Lewis debit card warning centres on a simple financial misunderstanding: many consumers believe paying with a debit card is always safer because they are spending money from their own bank account.

That is true when the account has sufficient funds. However, when the balance drops below zero and an overdraft is used, further debit-card purchases are effectively funded by borrowing.

Speaking about overdraft costs, Martin Lewis warned:

“If you are overdrawn your debit card is a debt card too.”

His wider point is that consumers should examine the actual cost of borrowing instead of assuming one type of card is automatically better.

For example, a credit card charging 24.9% APR could have a lower borrowing rate than an overdraft charging 39.9% EAR. However, those percentages use different rate conventions, and the real cost depends on repayment timing and account terms.

There are four main issues behind the warning:

• Overdraft Interest: Debit-card spending while overdrawn can attract substantial interest.
• Debt Repayment: Clearing expensive overdraft borrowing may sometimes deserve priority over cheaper credit-card debt.
• Purchase Protection: Credit cards may provide stronger statutory protection for qualifying purchases.
• Payment Security: Choosing Pay by Bank instead of a card can remove important card-scheme protections.

The warning is not an instruction to stop using debit cards. It is a reminder that responsible money management matters more than the name printed on the card.

Why Can Using a Debit Card Become More Expensive Than a Credit Card?

Debit cards normally access existing money held in a current account. The problem begins when customers spend beyond their available balance.

Consider someone with £150 remaining in their account.

During the week, they make the following purchases:

The account holder has spent £120 more than the £150 available.

If their bank permits this through an interest-bearing overdraft, that £120 becomes borrowed money.

Additional spending could increase the overdraft further, with interest continuing until the borrowed amount is repaid.

How Much Interest Do UK Overdrafts Charge?

Many mainstream UK current accounts have offered arranged overdrafts with rates close to 40% EAR, although individual banks and accounts may charge different rates.

Our financial assessment highlights the importance of distinguishing between borrowing rates and interest-free spending.

Rates are illustrations, not current quotes for every product. APR and EAR are not identical measures, so the figures should not be treated as an exact like-for-like cost calculation.

Why Do Overdraft Costs Often Go Unnoticed?

Our analysis identified three reasons overdraft borrowing can be underestimated.

First, an overdraft is attached to an everyday bank account, making the debt less visible than a separate credit-card statement.

Second, people regularly moving between positive and negative balances can begin treating their overdraft limit as part of their available income.

Third, overdraft interest can accumulate through repeated borrowing, even when individual purchases are relatively small.

Someone with a £1,000 overdraft limit may feel they have additional spending capacity. Financially, however, that facility is borrowed money that the bank may charge interest on.

Should You Pay Off Your Overdraft Before Your Credit Card?

Paying down the debt with the highest effective borrowing cost can save money, provided priority bills and required repayments remain covered.

Consider the following example:

The overdraft carries the higher quoted annual borrowing rate.

If both debts are accruing interest and there are no unusual fees or promotional arrangements, directing affordable extra repayments towards the overdraft could reduce borrowing costs.

However, repayment decisions should not be based on headline interest rates alone.

Households should first ensure they can cover priority commitments such as rent, mortgage payments, council tax and essential utilities.

They should also maintain the required payments on credit agreements to avoid arrears and additional charges.

Our assessment is that an overdraft should be treated as a genuine debt rather than an extension of monthly income.

Could a 0% Credit Card Help Clear an Overdraft?

Potentially, but the type of credit card matters.

A money-transfer credit card may allow customers to move funds into their bank account, which can then be used to reduce an expensive overdraft.

This differs from a standard balance-transfer card, which is generally designed to transfer eligible credit-card debts.

Before using a money-transfer offer, compare:

• Transfer Fee: The upfront percentage charged for transferring money.
• Interest-Free Period: How long the promotional rate lasts.
• Reversion Rate: The interest rate after the offer expires.
• Monthly Repayments: Whether the borrowing can realistically be cleared.
• Credit Eligibility: Whether an affordable offer is actually available.

People managing existing card debts can also compare balance transfer credit cards in the UK to understand how promotional rates, transfer fees and repayment periods affect their finances.

The important distinction is that a balance transfer and a money transfer are different facilities.

Does Martin Lewis Recommend Credit Cards Instead of Debit Cards?

Martin Lewis’s warning should not be interpreted as a blanket recommendation to replace debit cards with credit cards.

Both payment methods have advantages and disadvantages.

A credit card may offer useful purchase protection and an interest-free period on ordinary purchases when the statement balance is paid in full according to the provider’s terms.

However, a credit card can become expensive if customers repeatedly carry balances or make only minimum repayments.

A debit card can support better spending discipline because transactions normally reduce the customer’s available bank balance.

For someone who finds borrowing difficult to control, that visibility may be particularly valuable.

Our assessment is that the strongest approach depends on three factors: affordability, repayment discipline and the purpose of the purchase.

How Does Section 75 Protect Credit Card Purchases?

Section 75 of the Consumer Credit Act 1974 is one of the most important protections available to eligible UK credit-card customers.

It can make the credit provider jointly liable with the supplier when there has been a qualifying breach of contract or misrepresentation.

This may help customers recover money when a retailer fails to deliver goods, a company becomes insolvent before supplying a service or a product is materially misrepresented.

The normal purchase-price requirement is:

More than £100 and no more than £30,000.

This means a qualifying £100.01 purchase may receive Section 75 protection, whereas an individual item costing exactly £100 generally falls below the threshold.

Can You Pay Only a Deposit by Credit Card?

Yes, potentially.

Imagine a couple booking a £3,000 holiday.

They pay £50 as a deposit using a credit card and the remaining £2,950 using another payment method.

If the purchase meets the relevant Section 75 requirements, paying only the deposit by credit card may still make the credit provider liable for a qualifying claim relating to the wider purchase.

The protection is not necessarily restricted to the amount charged to the credit card.

However, several conditions matter, including the relationship between the customer, creditor and supplier.

Payments through certain intermediaries or third-party services can complicate eligibility.

Does Spending More Than £100 Always Qualify?

No.

The cash price of the qualifying item or set of items matters, rather than simply the overall checkout total.

For example:

A £150 shopping basket containing three unrelated £50 items does not automatically qualify simply because the combined bill exceeds £100.

Consumers should therefore consider Section 75 requirements before making expensive purchases, not only after a dispute occurs.

What Protection Do Debit Card Users Have?

Debit-card users may be eligible for chargeback when a purchase goes wrong.

Unlike Section 75, chargeback is not a statutory consumer-credit right. It operates through card-network rules, including arrangements associated with Visa and Mastercard.

Chargeback may help when:

• Goods never arrive.
• A service is cancelled without the required refund.
• Products are defective or significantly different from their description.
• A merchant agrees to refund a payment but fails to process it.
• A retailer stops trading before supplying the goods.

However, chargeback is not guaranteed. Banks must assess whether the transaction meets the relevant card-scheme requirements.

How Long Do You Have to Make a Chargeback Claim?

A common chargeback timeframe is 120 days.

The starting point can depend on the circumstances. For example, where goods or services are due to be provided at a future date, the relevant period may begin from the expected delivery or event date.

Some card-scheme rules also involve other limits and exceptions.

Customers should therefore contact their card provider as soon as a problem becomes apparent rather than assuming they have unlimited time.

What Is the Difference Between Section 75 and Chargeback?

These protections serve different purposes and should not be confused with deposit protection under the Financial Services Compensation Scheme.

The official MoneyHelper explanation of Section 75 and chargeback confirms these important distinctions.

MoneyHelper explains the purchase-price limits for Section 75 protection and why debit-card payments rely on different refund arrangements.

The screenshot illustrates a crucial distinction: an eligible credit-card payment can create a statutory claim against the credit provider, whereas a debit-card chargeback follows the applicable card-scheme process.

Why Has Martin Lewis Warned People About Pay by Bank?

Another important warning concerns the growing availability of Pay by Bank at online checkouts.

Customers may increasingly encounter payment options that allow them to authorise purchases directly through their banking app.

This can be convenient, but it is fundamentally different from paying with a debit or credit card.

Pay by Bank generally uses Open Banking payment initiation technology to arrange a bank transfer.

It does not automatically turn that transfer into a card transaction.

MoneySavingExpert highlighted Martin Lewis’s warning about the limited card-style protection associated with this payment method.

How Does Pay by Bank Work?

The process typically involves four steps:

1. The customer selects Pay by Bank at checkout.
2. The customer chooses their bank.
3. The banking app opens to authorise the payment.
4. The payment is made directly from the account.

Although the experience can resemble an ordinary app-based card payment, the underlying transaction is different.

This matters because normal card chargeback rules and Section 75 protection generally do not apply to an ordinary bank transfer.

That does not mean customers lose their underlying rights against the retailer. It means they may have fewer ways to recover the money through their payment provider.

Is Pay by Bank Safe for Large Purchases?

The technology itself is not necessarily unsafe. The concern is the protection available when a transaction goes wrong.

For example, someone purchasing a £2,000 laptop from an unfamiliar online retailer might have a stronger financial safety net by using a qualifying credit card.

If they instead use Pay by Bank and the retailer never delivers the laptop, they cannot simply make a conventional debit-card chargeback claim because no debit-card transaction took place.

Our assessment is that buyers should be particularly cautious when paying unknown retailers or making expensive purchases where delivery or service fulfilment will happen later.

What Happens If a Bank Transfer Turns Out to Be a Scam?

A distinction must be made between an ordinary commercial disagreement and authorised push payment fraud.

A customer who knowingly pays a legitimate retailer and later disputes the product is not automatically entitled to reimbursement under scam-protection rules.

By contrast, someone deceived into transferring money to a criminal may be eligible for reimbursement under UK authorised push payment (APP) scam protections.

Since 7 October 2024, qualifying APP scam payments made through Faster Payments or CHAPS have been covered by a mandatory reimbursement framework, subject to the rules and exclusions.

The standard maximum reimbursement is £85,000 per qualifying claim.

According to the Payment Systems Regulator’s July 2026 reporting, 88% of the value of money lost in in-scope APP scam cases was reimbursed during the first 18 months of the regime, totalling approximately £316 million.

That is a reported market outcome, not a guarantee that any particular individual claim will succeed.

The Payment Systems Regulator’s APP scam reimbursement information helps explain how the system has performed.

Important: APP scam reimbursement is not a substitute for Section 75 or chargeback when a normal purchase dispute arises.

How Do Debit Cards, Credit Cards and Pay by Bank Compare?

Our editorial review considered borrowing costs, purchase protection, spending control and convenience.

The following percentages are illustrative editorial suitability scores, not customer survey findings, refund probabilities or guarantees. They assess each payment method in the scenario specified.

How Were These Ratings Assessed?

The ratings reflect our editorial judgement across four considerations:

• Borrowing Costs – 40% weighting: Whether interest, fees or borrowing are involved.
• Purchase Protection – 30% weighting: The nature of the applicable consumer protections.
• Debt Control – 20% weighting: How effectively the payment method can help avoid unaffordable spending.
• Convenience – 10% weighting: Ease of use and transaction management.

These are scenario-based assessments, not results from an independently conducted customer survey.

The scores would change for a consumer with different needs or repayment habits.

For example, someone unable to control credit-card spending may reasonably prefer a debit card even for purchases where credit-card protection could otherwise be useful.

What Should You Do If a Debit Card Payment Goes Wrong?

Consumers should distinguish between three situations: a retailer dispute, an unauthorised card transaction and a bank-transfer scam.

Each can involve a different complaints or reimbursement process.

Step 1: Identify the Transaction

Check the amount, merchant name, date and payment method.

Determine whether the transaction was made using a debit card, credit card or bank transfer.

Step 2: Contact the Retailer Where Appropriate

For ordinary purchase disputes, explain the problem and request a suitable remedy.

Keep copies of receipts, order confirmations and correspondence.

If the transaction was unauthorised or fraudulent, contact the bank immediately rather than waiting for the retailer.

Step 3: Contact Your Card Provider

If the retailer refuses an appropriate refund, ask the card provider whether chargeback or Section 75 applies.

For debit-card purchases, explain that you want the bank to consider a chargeback request.

For qualifying credit-card purchases, ask the lender to assess a Section 75 claim.

Step 4: Provide Supporting Evidence

Useful documents can include:

• Purchase receipts.
• Order confirmations.
• Bank or card statements.
• Screenshots of the advertised product.
• Delivery records.
• Correspondence with the retailer.
• Photographs showing faults or damage.

Step 5: Escalate an Unresolved Complaint

If the bank or credit provider handles a claim unfairly, customers can make a formal complaint.

The Financial Ombudsman Service may be able to investigate if the provider issues an unsatisfactory final response or does not respond within the applicable deadline.

For many complaints, the standard period is eight weeks, although certain payment-service complaints can have shorter response deadlines.

Consumers should check the applicable process and referral time limits.

What If Your Debit Card Is Used Without Permission?

An unauthorised transaction is not the same as a customer voluntarily paying a retailer for goods that never arrive.

If somebody steals a debit card or card details and makes unauthorised payments, separate payment-services protections may apply.

The account holder should immediately:

• Freeze or cancel the affected card.
• Notify the bank’s fraud department.
• Review recent transactions.
• Change compromised banking credentials.
• Preserve messages or other evidence.
• Report additional suspicious activity.

Banks must investigate disputed transactions under the relevant legal framework. Refund rights can apply, but the circumstances and any applicable exceptions must be considered.

Customers should not assume they have to accept financial losses merely because criminals obtained their card details.

Are Monzo and Other Digital Debit Cards Affected by the Same Warning?

Yes. The key principles also apply to app-based banking.

A debit card issued by a digital bank remains a debit card.

It does not automatically acquire Section 75 protection because the bank offers sophisticated fraud detection, spending notifications or savings products.

However, digital banking tools may help customers manage their spending more effectively.

For example, instant transaction alerts, spending limits and card-freezing controls can help users identify suspicious activity or prevent accidental overspending.

Our comparison of digital banking protections found that understanding the difference between deposit guarantees, fraud reimbursement and card purchase disputes is especially important. These issues are also relevant when assessing whether Monzo is safe for everyday banking.

Customers comparing account features may also find practical differences between Revolut and Monzo, particularly around budgeting, borrowing and international payments.

Neither bank’s app-based convenience changes the basic distinction between debit-card chargeback and credit-card Section 75.

Should You Use a Debit Card or Credit Card Abroad?

International spending introduces another layer of financial risk.

Both debit and credit cards can charge fees for transactions made in foreign currencies, although some products are designed to reduce these costs.

Consumers should consider:

• Foreign transaction fees.
• Exchange rates.
• Cash withdrawal charges.
• Interest on credit-card cash advances.
• Purchase protection.
• Dynamic currency conversion.

For example, a card with no foreign transaction fee may be economical for overseas purchases but expensive for ATM withdrawals.

Customers checking Monzo’s overseas card charges can see why foreign purchases and cash withdrawals need to be assessed separately.

Why Should You Avoid Credit Card Cash Withdrawals?

A credit-card cash withdrawal is normally treated differently from an ordinary purchase.

It may trigger a cash-advance fee and interest from the transaction date.

That means a credit card offering an interest-free period for retail spending can still be expensive when used at an ATM.

Before travelling, understanding the costs of withdrawing cash from a credit card can help prevent avoidable charges.

What Changed About Buy Now Pay Later Protection in 2026?

Another important development concerns Buy Now Pay Later agreements.

From 15 July 2026, the Financial Conduct Authority began regulating certain third-party Deferred Payment Credit arrangements.

Qualifying agreements entered into from that date may now benefit from additional consumer-credit protections, including Section 75 where the legal requirements are satisfied.

However, this does not mean every instalment arrangement or retailer-funded payment plan receives identical protection.

Consumers must check the agreement date, provider, legal structure and purchase eligibility.

These changes reinforce the importance of examining how a purchase is financed rather than assuming all digital payment options carry the same rights.

What Are the Biggest Debit Card Mistakes to Avoid?

Based on our financial assessment, several mistakes create unnecessary costs or weaken consumers’ financial position.

Treating an Overdraft as Available Income

An overdraft is borrowing, not a salary increase or an extension of savings.

Regular dependence on the facility can make household finances harder to control.

Paying Expensive Debts in the Wrong Order

Consumers sometimes focus on the debt that feels most worrying rather than comparing its borrowing cost.

The better approach is to protect essential commitments, maintain required payments and assess which debts are most expensive.

Assuming Debit Cards Have No Consumer Protection

Debit-card chargeback can be valuable when a retailer fails to provide goods or services.

The problem is not that debit cards offer no protection, but that their protection differs from Section 75.

Believing Every Credit Card Purchase Is Covered

Section 75 has eligibility conditions.

The purchase price, type of credit, supplier relationship and payment arrangement can all influence whether a claim succeeds.

Using Credit Cards Without a Repayment Plan

Purchase protection should never be used as an excuse to borrow more than a household can afford.

A credit card with a high interest rate can quickly erase any benefit associated with rewards or additional protection.

Customers considering a card primarily for borrowing or credit-building should compare the actual offered APR. For instance, our assessment of the Zable credit card shows how different products within one provider’s range can have substantially different interest rates.

Choosing Pay by Bank Without Checking the Risks

Bank-transfer checkout options can be convenient, but they do not automatically provide the same protection as paying by card.

This matters particularly for high-value purchases and unfamiliar retailers.

What Is Our Final Assessment of Martin Lewis’s Debit Card Warning?

The strongest lesson from Martin Lewis’s debit card warning is that the real cost of spending depends on how the payment is funded.

A debit card is usually sensible for everyday purchases when sufficient money is available.

The situation changes when the account enters an expensive overdraft.

A credit card can provide useful protection for qualifying purchases and may allow interest-free spending when repaid under the correct terms. However, carrying expensive credit-card debt is not a responsible alternative to overdraft borrowing.

Pay by Bank introduces a further consideration. Consumers should understand that a bank transfer does not automatically provide the same card-based refund mechanisms as a debit or credit card.

Our review therefore supports a straightforward approach: compare borrowing costs, protect essential spending, review the payment method before expensive purchases and understand what happens if something goes wrong.

For people regularly using an overdraft, reviewing the interest rate and repayment options may be one of the most valuable financial decisions they can make.

Frequently Asked Questions

Is Martin Lewis Telling Everyone to Stop Using Debit Cards?

No. His warning concerns expensive overdraft borrowing and the different protections offered by payment methods, not a universal recommendation to avoid debit cards.

Is a 40% Overdraft More Expensive Than a 25% Credit Card?

It can be. However, overdraft EAR and credit-card APR are different measures, so actual costs must be compared using the balance, fees and repayment period.

Can You Get a Refund for a Debit Card Purchase?

Potentially. Chargeback may help when goods are not delivered, services are cancelled or a retailer fails to provide an appropriate refund.

Does Paying £1 by Credit Card Provide Section 75 Protection?

It can for a qualifying purchase, provided the full cash price of the relevant item exceeds £100 and all other Section 75 requirements are satisfied.

Is Pay by Bank the Same as Paying With a Debit Card?

No. Pay by Bank generally initiates a bank transfer and does not automatically provide card-scheme chargeback or credit-card Section 75 protection.

Are Contactless Debit Card Payments Protected Against Fraud?

Unauthorised contactless transactions may be covered by payment-services refund protections. Customers should report suspicious transactions immediately.

Can You Use a Credit Card Without Paying Interest?

Usually, ordinary purchase interest can be avoided by paying the required statement balance in full on time, subject to the card’s terms. Cash advances and certain other transactions are treated differently.