How the Current Account Switch Service Works in the UK
CASS can move an eligible UK current account to another participating bank or building society in seven working days. The important part is knowing exactly what moves, what does not, and what evidence to keep if the switch goes wrong.
What the Current Account Switch Service actually does
The Current Account Switch Service, usually shortened to CASS, is the UK service used to move an eligible current account from one participating bank or building society to another. The service itself is free. A full CASS switch is designed to complete in seven working days once the new account is open and the switch date has been agreed.
On the agreed switch date, the old current account is closed, the remaining balance is transferred to the new account and regular incoming and outgoing payments are moved. That normally includes salary or benefit payments, Direct Debits and standing orders. Payments accidentally sent to the old account after the switch are redirected to the new one, and the sender is told about the new account details so they can update their records.
CASS is not a general transfer service for every banking product. It does not switch savings accounts or ISAs. If you want to move a Cash ISA, use the provider's ISA transfer process rather than withdrawing the money yourself if preserving the tax wrapper matters. Savings balances also need to be moved under the rules of the savings product, not through CASS.
It is also important to separate the account switch from any switching bonus. CASS controls the mechanics of moving the current account. A bank's promotional offer has its own eligibility rules, deadlines, pay-in requirements and Direct Debit conditions. You can complete a valid CASS switch and still miss a promotional reward if you fail one of the separate offer conditions.
The seven-working-day process step by step
Account opening and account switching are separate processes. Your new bank first has to complete its account-opening checks. Only after the new account is ready can you agree the CASS switch date. The switch date must allow at least seven working days and cannot be a Saturday, Sunday or bank holiday.
Before the switch starts, compare the old and new accounts on the features you actually use. Check monthly fees, overdraft pricing, cash access, branch or app access, card use abroad, rewards and any linked savings products. If the new account only looks attractive because of a one-off bonus, calculate the value again with the bonus removed. The destination account should still make sense after the promotion is over.
During the seven-working-day switching period, avoid setting up new Direct Debits or standing orders on the old account. CASS says new payment arrangements created at the old bank during the seven working days leading up to the switch date will not be transferred automatically. If you need to create a new regular payment in that period, set it up on the new account instead.
On the switch date, the new bank becomes the main account. The old account is closed, the balance is moved and regular payments are transferred. CASS also transfers saved payee details that are directly linked to the old account for internet or telephone banking. Keep the old account statements somewhere safe before the account closes, especially if you may need them later for tax, proof of payment or a complaint.
What to check before you start the switch
Start with eligibility. Both the old and new providers need to participate in CASS. If either provider is outside the service, you will need to ask the new bank what alternative transfer process it offers. For a personal joint account, both account holders must agree to the switch, and CASS says a joint account can be switched only to another joint account, not to a sole account.
Check any overdraft before you choose the switch date. You can use CASS while overdrawn, but an overdraft does not automatically follow you to the new bank. You need to agree any new overdraft facility with the destination bank, subject to its lending checks. If no new facility is agreed, you need another plan to repay the old overdraft.
Make a written list of the important payment flows on the old account. Include salary, benefits, Direct Debits, standing orders, card subscriptions and any large payments due close to the switch date. CASS should move regular incoming and outgoing payments, but a simple checklist makes it easier to spot a problem quickly. It also gives you useful evidence if a bill is missed or a salary payment is delayed.
If you are switching for a promotional incentive, save a copy of the offer terms on the day you apply. Record the application date, switch date, required pay-in, number of Direct Debits, debit-card-use requirements and the promised reward-payment date. Treat each condition as a separate item. This prevents a common problem where the account switch succeeds but the customer later discovers that the bonus had a different deadline.
What happens to payments, cards, overdrafts and joint accounts
Regular incoming payments such as salary should be redirected if they are sent to the old account after the switch. CASS also redirects payments accidentally sent to the old details after closure. This is useful, but you should still update important organisations directly when practical, especially employers, pension providers, benefit administrators and anyone who pays you infrequently.
Direct Debits and standing orders are transferred as part of a full switch. Even so, check the first collection after the switch for critical bills such as rent, mortgage, council tax, utilities, insurance and credit commitments. A moved instruction can be correct while a separate merchant issue still causes a payment problem. Keeping enough money in the new account for the first payment cycle reduces the risk of an avoidable shortfall.
Debit cards do not transfer between banks. Your old card belongs to the old account and will stop being usable when that account closes. Make sure the new card, PIN and app access are working before the switch date if you depend on the account for everyday spending. Card refunds sent to the old debit card after the switch should be routed to the new bank, but if an expected refund does not arrive, contact the new provider.
For joint accounts, both parties must consent and the destination account must also be joint. For overdrafts, agree the new facility before the switch if you need one. Do not assume the old limit, interest rate or terms will be reproduced. The new bank assesses the overdraft under its own lending criteria, so the approved amount may be lower or the application may be declined.
What to do if something goes wrong
The Current Account Switch Guarantee covers failures in the switching process. If the switch causes you to incur charges or lose interest, the new bank or building society is responsible for correcting the problem under the Guarantee once it is told about the issue. The Guarantee also covers the core switch tasks such as moving the balance and payments and closing the old account.
If a problem appears, contact the new bank first. Write down the date, the payment affected, the amount, what should have happened and what actually happened. Keep screenshots, statements, offer terms and any messages from the bank. If a Direct Debit failure caused a late fee or affected your credit file, include evidence of that consequence as well as evidence of the failed payment.
If the issue is not resolved, make a formal complaint to the provider. The Financial Ombudsman Service says it deals with complaints about current account switching, including delayed switches, Direct Debit problems, charges, credit-file issues, missing switch incentives and overdraft problems. The Ombudsman looks at whether the provider met the switch guarantee and what information it gave the customer.
The practical lesson is to separate three questions. First, did CASS complete the mechanical switch correctly? Second, did the bank meet any promotional offer terms it promised? Third, did the destination account remain suitable after the switch? Keeping those questions separate makes it much easier to work out what went wrong and what evidence you need.
BankOfferScout editorial view
The editorial lens on How the Current Account Switch Service Works is deliberately practical: model the complete qualification checklist and destination-account fit, then judge eligibility, deadlines, switching mechanics and the ongoing value of the destination account. This reduces the chance that a temporary headline benefit dominates a decision it should not control.
The editorial test for How the Current Account Switch Service Works is whether the choice still works under normal behaviour. We stress-test the comparison for missing a qualifying action or moving to a poor-fit destination account. If two options are close, simpler conditions and a better fit for normal behaviour can be more valuable than a marginal numerical edge that is easy to lose.
Before acting on How the Current Account Switch Service Works, verify cash incentives, eligibility exclusions, pay-in rules, Direct Debit requirements, deadlines and account features using the provider switching page, incentive terms and destination-account tariff. If the answer depends on a rule outside the provider, confirm it through the Current Account Switch Service or another authoritative process source. BankOfferScout supplies the decision framework rather than freezing live product data in time.
Sources and next steps
Primary sources checked for this guide include the Current Account Switch Service pages on the service, personal switching process, common personal questions and the Current Account Switch Guarantee, plus Financial Ombudsman Service guidance on current account switching complaints. Product-specific fees, bonuses, eligibility rules and overdraft terms can change and should be checked with the provider immediately before acting.
Related BankOfferScout guides to link from this page: Bank Switching Eligibility Explained, Bank Switching Deadlines Explained, What Happens to Direct Debits When You Switch, What Happens to Salary Payments When You Switch, Can You Switch a Joint Account and Bank Switch Delayed: What to Check. For future reviews, recheck the seven-working-day CASS timetable, redirection guarantee, joint-account rules and complaint guidance against the Current Account Switch Service and Financial Ombudsman Service before changing any worked example. Product-specific switch bonuses should be kept out of this core process guide unless they are clearly date-stamped, because promotional eligibility changes much faster than the underlying CASS mechanics. Related Guides are listed above for the reader's next practical step.