Building society mergers and name changes

Building societies merge with one another, take over smaller societies, and sometimes change their names, and when they do the practical question for customers is what happens to their money, their mortgage and their paperwork. In most cases the answer is reassuring: accounts carry on, direct debits keep running, and the society writes to you before anything changes. But a merger can change your account terms, your membership rights and, in one important respect, how much of your money is protected by the Financial Services Compensation Scheme (FSCS), which covers up to £120,000 per person, per banking licence¹.

A merger is not the same as a society converting into a bank. Between 1989 and 2000, ten building societies changed their status completely, converting into or merging with a plc bank², and the Building Societies Association (BSA) publishes details of mergers, name changes and conversions going back to 1937². Today the BSA represents all 42 UK building societies, including both mutual-owned banks, which together operate through approximately 1,300 branches³ and hold total assets of almost £650 billion⁴.

This page explains what a merger means for your accounts, your cards, your mortgage and your vote as a member, how to trace an old account with a society that has disappeared or been renamed, and where to complain if the change goes wrong for you.

What happens when building societies merge

A merger combines two mutual organisations into one. Building societies are "mutuals", meaning they are owned by their members rather than by outside shareholders⁷. When two societies merge, the smaller or transferring society's business, its savings accounts, mortgages and branches, is absorbed into the continuing society, and its members normally become members of the combined organisation. A name change is simpler still: the same society keeps trading under a new name, and nothing about its legal structure or licence changes.

For customers, the process usually begins with a letter. The society or societies involved write to savers and borrowers explaining what is proposed, what will happen to accounts, and when any changes take effect. Mergers between building societies require the approval of members, so the letter is normally accompanied by voting papers and information about the proposal, and the merger proceeds only if members approve it. The BSA, the trade association representing mutual lenders and deposit takers including all of the UK's building societies⁵, keeps records of past mergers and name changes stretching back to 1937, which is useful if you need to work out which society now holds an account you opened decades ago².

In practice, most customers notice three things after a merger: new branding on statements, cards and passbooks; a change of app or online banking platform in some cases; and, occasionally, changes to account terms. What does not usually change is the money itself. Your balance, your mortgage debt and your payment arrangements carry across, and the merged society becomes responsible for them. The sections below take each of these in turn.

Is a building society merger the same as demutualisation?

No, and the difference matters for what you own and what you are entitled to. A merger between two building societies keeps the mutual structure intact: the combined society remains owned by its members, and members keep their say in how it is run⁷. Demutualisation, usually called conversion, is when a society abandons mutual status and becomes a bank owned by shareholders. That ends member ownership, which is why a conversion has to be put to a member vote before it can happen.

Conversions were a feature of a particular period: between 1989 and 2000, ten building societies changed their status completely, converting into or merging with a plc bank². Some of the best-known high street banking names began life as building societies. The BSA's records of mergers, name changes and conversions, going back to 1937, let you check what happened to any society you once saved with or borrowed from².

The tax and windfall rules treat the two differently. Regulations define a "building society bonus" and normally exclude any bonus paid on the demutualisation of a building society from that definition⁸. The same regulations exclude from the definition any bonus, distribution of funds or conferring of rights in shares made in connection with an amalgamation, transfer of engagements or transfer of business of a building society⁹. In plain terms: a merger between societies is not normally a windfall event, whereas a conversion to a bank historically was, and any payout on conversion is treated under its own rules rather than as an ordinary bonus.

Your account number, sort code and card after a merger

What happens to your account number and sort code depends on how the merger is structured. Some building societies hold their own unique sort code, send funds for customers over CHAPS or Faster Payments, and have accounts that consumers and businesses can make and receive payments from¹⁰. Where the transferring society's sort codes are absorbed into the continuing society's banking arrangements, account details can change, and the society will write to you with new details and new cards before the old ones stop working.

When details change, the society normally handles the transition. Where there is an arrangement in place, your bank or building society must transfer any account balance and make arrangements for your direct debits and standing orders, and you do not have to pay for bank charges caused by mistakes or delays in the transfer¹¹. If you are moving accounts yourself rather than waiting for the merger to complete, the process involves opening the new account before closing the old one, cancelling or moving standing orders and direct debits, returning unused cheques, and cutting cards into pieces¹¹. The step-by-step guide to switching your bank account covers this in detail.

Cards are usually reissued in the new society's name, and old cards stop working on a stated date. Keep an eye on any recurring card payments tied to the old card number; the page on what happens to recurring card payments when you get a new card explains the difference between these and direct debits. If you hold documents such as passbooks or share certificates issued by the old society, keep them: they remain evidence of your holding even after the name on the front has changed. NS&I, which runs its own account-merging process, asks customers writing in about merging accounts for their name, date of birth and home address, plus the type of investment, its approximate start date, the amount invested, and any holder's, customer, account, Bond or Certificate numbers¹², and a society absorbing accounts will ask for similar details.

Savings rates and account terms: what can change

A merger can change the terms of your savings accounts, but not instantly and not silently. The merged society must tell you before changes take effect, and the merger letter usually sets out which accounts continue unchanged, which are renamed or replaced, and what happens to notice periods, withdrawal rules and rates. Interest rates themselves are set by the society, and rates on savings accounts can move over time regardless of any merger; interest on cash deposits often fails to keep pace with inflation¹³, so it is worth reviewing where your money sits after a change, not because the merger has cost you anything but because it is a natural moment to check.

Some account features are protected by rules that a merger does not override. Savings accounts must display a Summary Box setting out the key terms, and where a firm uses the annual equivalent rate (AER) it should take account of the British Bankers' Association and Building Societies Association code of conduct for the advertising of interest bearing accounts¹⁴. So after a merger you can still expect the new society's literature to show the AER and the terms in a standard format, making accounts comparable.

One structural point is worth knowing. Building societies generally offer share accounts, which carry membership, and some also offer deposit accounts, which do not. Under the Building Societies Act 1997 there are exceptions where customers may still open deposit accounts, including current accounts, client or trustee accounts, qualifying time deposits, deposits at overseas branches, and where the society has announced publicly that it intends to transfer its business to a company¹⁵. If you hold a deposit account rather than a share account, you are a customer rather than a member, and depositors are not members and have no member rights⁵. A merger does not change which kind of account you hold, but it may matter for your vote, covered below.

If you are unhappy with the new terms, your options depend on the account. Notice accounts require the stated notice, fixed-term accounts may restrict access, and instant access accounts can usually be closed freely. Some banks and building societies offer incentives to switch, such as money, lower overdraft fees or a better interest rate¹³, so it can be worth comparing. The guide to savings accounts explains the account types, and dormant bank accounts covers what happens if you leave an account untouched.

Mortgages after a merger or name change

If you have a mortgage with a society that merges or changes its name, the loan itself is unaffected: the debt, the term and the agreed rate continue under the new society, which steps into the shoes of the old one. Your monthly payment arrangement, normally a direct debit, carries across, and the society writes to confirm who to contact and where to send any correspondence. What may change over time is the range of products on offer when your current deal ends, since the merged society will have a single mortgage range rather than two.

When a fixed or discounted rate ends, you move to the merged society's standard variable rate or can choose a new deal, either with the same society or by remortgaging. Remortgaging occurs when existing borrowers redeem their current mortgage in favour of a new one secured on the same property, but with a different mortgage lender¹⁶. A merger does not lock you in: you remain free to remortgage elsewhere at the end of any tie-in period, subject to any early repayment charges in your original terms. Many building societies have signed the Mortgage Charter, a government-backed commitment whose signatories include societies such as Nationwide, Coventry, Leeds, Skipton, Yorkshire, Principality, Newcastle and many others, alongside the major banks¹⁷.

Name changes on a mortgage can also arise from personal circumstances rather than mergers. If a joint mortgage is restructured after a separation, the person whose name is taken off the mortgage should be able to borrow more to buy themselves a home than if their name was still on their ex-partner's mortgage¹⁸. And if you have been through repossession, you might have to pay a higher deposit or interest rate on a later mortgage¹⁸, whoever the lender is. The guide to mortgages covers these situations, and changing your name on bank and financial accounts explains the paperwork for a personal name change.

FSCS protection: up to £120,000 per person, per banking licence

This is the one area where a merger can genuinely change your protection, so it is worth understanding how the limit works. FSCS protection for banks, building societies and credit unions is up to £120,000 per person, per banking licence¹. The limit applies per authorised firm, not per brand or per account: if you hold money with two building societies that merge, and they come under a single banking licence, your combined balances now count together towards one £120,000 limit¹. Before the merger you had two separate limits, one with each society.

The current figure of £120,000 is the one that applies to failures from 1 December 2025 onwards, when FSCS began compensating up to £120,000 per eligible person, per bank, building society or credit union¹⁹. Earlier FSCS literature put the limit at £85,000 per person or company, per authorised firm²⁰, so older guides and leaflets you may still have will show the previous figure. If a merger letter tells you the combined society holds a single licence, and your total balances across the two old societies exceed £120,000, the excess is not protected, and you may want to consider spreading your money across separately licensed firms. The FSCS publishes a list of banking licences showing which brands share one¹.

There is one further rule specific to building society mergers. Under the FSCS compensation sourcebook, in the event of a merger between two building societies there is a separate and additional £50,000 maximum payment limit for a claimant with respect to claims for protected deposits held under the name of the dissolved building society²¹. The rule, which dates from the 2008 to 2009 period when the general limit was lower, also applies to mergers between a building society and the subsidiary of another mutual society, and the successor entity must make and retain a written record of potential claimants for whom the separate limit applies²². In practice this means a depositor of a society that was dissolved in a merger may have an additional protected amount for deposits held under the old society's name, on top of their limit with the combined society. If you think this might apply to a large historic balance, ask the society and check with FSCS, which can confirm what is covered¹⁹.

Your member vote and what it covers

Building societies operate on the principle of "one member, one vote"⁵. Members have a say in how the organisation is run, including charity partnerships and decisions about running the society⁷, and a merger is one of the biggest decisions members are asked to make. Shareholders, as members, have the right to receive information on the activity of the society, including the summary financial statement, and notification of the annual general meeting and any special general meeting¹⁵. They can vote in elections for the board of directors, attend annual general and other meetings and, providing the correct procedures are followed, propose motions or stand for election themselves¹⁵.

Voting eligibility has conditions. Members have one vote each regardless of the size of their savings account or mortgage loan, subject to there being a minimum savings balance or mortgage debt of £100, being over the age of 18, and being a member throughout the period between the end of the financial year and the date of the AGM⁵. Saving members with less than £100, borrowing members with a mortgage of less than £100, and members under 18 have restricted rights, allowing them only to receive information on request⁵. Most societies have a financial year ending in December and usually hold their AGMs in the following April⁵.

One detail is specific to mergers. If you are both a saver and a borrower with a society, you will still normally have just one vote, except when asked to vote on a conversion or merger, when two separate votes are given⁵. Most societies also hold an advisory vote on the directors' remuneration report at the AGM, although this is not required by law⁵. If you want to raise an issue at the AGM rather than just vote, the guide to putting forward a resolution at a building society AGM explains the procedure.

Branches, apps and ways to bank after the change

A merger often means a reshaping of how you bank day to day. Branch networks can be combined, with some branches closing where two societies overlapped in the same town, and apps and online banking platforms are sometimes merged into one. Building societies and mutual-owned banks as a whole operate through approximately 1,300 branches, a 30% share of branches across the UK³, so branch access remains a real strength of the sector, but the pattern in your area can change after a merger. A bank or building society current account is the easiest way to access your payments²³, and that does not change: whichever society holds your account after the merger, your current account keeps doing the same job.

Service disruption is possible during the transition, as with any systems change. When Nationwide, the UK's largest building society, suffered a technical issue in February 2025, faster payments were delayed and temporarily queued, while Bacs payments were unaffected, meaning direct debits and standing orders continued as normal, and cards, internet banking and ATM withdrawals kept working²⁴. The lesson for a merger is that payment types can be affected differently: a delay to one system does not necessarily stop your direct debits. If a payment goes missing during a merger transition, contact the society, and keep a note of what was due and when.

If the merged society's ways of banking do not suit you, for example if your nearest branch closes and you need counter service, you are free to move your current account elsewhere. Guidance on changing your bank or building society suggests opening a new account before closing the old one, cancelling or moving standing orders and direct debits, and returning unused cheques and cut-up cards¹¹. The page on provider takeovers and account migrations covers the wider picture when firms combine.

Dormant and lost accounts from societies that no longer exist

Many people hold, or are owed money in, accounts with societies that have since merged or vanished under a new name. The money does not disappear with the name. The Dormant Bank and Building Society Accounts Act 2008 set up a framework under which money in dormant bank and building society accounts can be distributed for social or environmental purposes, while ensuring the right of owners to reclaim their money is protected²⁵. Banks and building societies that opt into the scheme can transfer the money held in dormant accounts to a central reclaim fund²⁶, and the dormant assets scheme introduced by the Dormant Assets Act 2022 supersedes the general scheme under Part 1 of the 2008 Act²⁷.

Crucially, transferring a dormant balance to the reclaim fund does not extinguish your right to the money. Once a transfer has happened, the customer no longer has any right against the bank or building society to payment of the balance, but has against the reclaim fund whatever right to payment of the balance the customer would have against the bank or building society if the transfer had not happened²⁸. The Act also covers accounts of people who have died: a reference to an account a person holds includes an account held by a deceased individual immediately before their death, with the customer read as the person to whom the right to payment has passed²⁸. For building society members, membership rights are preserved where the balance of a dormant account held by a member is transferred, until the point at which the customer is repaid²⁹.

To trace an old account, use My Lost Account, a free service that brings together three tracing schemes: UK Finance, the Building Societies Association and National Savings and Investments (NS&I)³⁰. The service is associated with UK Finance and the Building Societies Association³¹, and a search can be carried out by using a free application online³². There are separate paper forms depending on where the account was held: a UK Finance form for lost accounts with banks, or with building societies that have become banks; a BSA form for current building societies; and an NS&I form for NS&I products³⁰. Because the BSA's records of mergers, name changes and conversions go back to 1937², you can first work out what happened to your old society, then direct your search to the right scheme. The guides to dormant bank accounts and the Dormant Assets Scheme and Reclaim Fund explain the process in full.

Where to complain if a merger affects you

If something goes wrong, for example a payment missed during a systems change, an account term changed without proper notice, or a dormant balance you cannot get repaid, complain to the society first. Every building society must have an internal complaints procedure, and using it is a necessary step before anything else can happen: the Financial Ombudsman Service, which handles complaints data across financial products³³, will normally only look at a complaint once the firm has had the chance to resolve it, or after eight weeks. The guide to writing an effective complaint letter or email covers how to set out what went wrong and what you want done, and what to do if a company hasn't replied to your complaint covers the next step.

If the society's answer is not satisfactory, you can refer the complaint to the Financial Ombudsman Service, which is free for consumers. Where a merger has left you unsure who is responsible, complain to the society that now holds your account, since it has taken over the old society's obligations. If the issue concerns FSCS protection or a dissolved society's deposits, FSCS itself can confirm what is covered and how to claim¹⁹. For general help at any stage, free consumer advice is available, and in Northern Ireland the Consumer Council can help with some complaints.

A few practical points strengthen a merger-related complaint. The merger letter and any terms notices you received serve as evidence, as do the dates of any missed payments or charges, and a society can be asked to confirm in writing what changed and when. If charges were caused by mistakes or delays in a transfer of your account, you do not have to pay them¹¹, and a refund can be requested as part of the complaint. And if the complaint is about someone else's account, for example a relative who has died, the guide to complaining on behalf of a relative or friend explains what authority you need.