Post-Merger Integration That Keeps Bank Clients

Transferring Clients Between Banks

Schwab moved over 17 million TD Ameritrade accounts in five waves. In post-merger integration, clients stay when told early and moved well.

Alexander Kiel

Business Analyst · Banking & Wealth Management

16.04.2025 · 7 MIN READ · BUSINESS INTEGRATION

ON THIS PAGE

1. Define the Perimeter

2. Choose the Legal Route

3. Ask Clients Early

4. Map Products and Mandates

5. Run Post-Merger Integration in Waves

6. Watch the First Weeks

Sample case: Charles Schwab

In short

FAQ

Banks are consolidating. KPMG counted a fall from 85 to 80 Swiss private banks in 2025 and expects the number to drop well below 70 by 2030. Each sale or merger ends with the same post-merger integration task: moving clients, accounts and assets from one bank to another.

When that move goes wrong, clients notice at once. In April 2018, TSB moved the data of about five million customers to a new platform. Up to 1.9 million of them could not use online or mobile banking and the bank received 135,403 complaints in the months that followed. The UK regulators later fined it £48.65 million for operational resilience failings.

Clients rarely choose to change bank in such a deal. How do you make sure they still want to stay once the move is done?

STEP 1

Define the Perimeter

Not every client in a book can or should move. Start with a clear list of what transfers: which clients, accounts, products and booking centres. Then decide what stays behind, such as clients from countries the buyer does not serve, products it does not offer or relationships that do not pass its risk checks.

The UK transfer of Sainsbury's Bank's business to NatWest shows how precise this must be. It covered certain credit cards, personal loans and savings accounts, with excluded assets and liabilities listed separately. For cross-border clients, FINMA expects banks to define a service model appropriate for each individual target market. A client the buyer cannot serve legally should not be part of the deal.

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List every client, account and product in scope

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Check each client's domicile against the buyer's target markets

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Agree in writing what happens to excluded clients

Does your team know today how many clients in the book the buyer cannot take?

Keep in mind: Excluded clients still need a solution. Plan their exit or transfer to a third bank as carefully as the main move.

STEP 2

Choose the Legal Route

There are two main ways to move clients. In the first, each client agrees to the transfer and opens a relationship with the new bank. In the second, a legal scheme moves the accounts collectively, without individual consent but under the supervision of a court or regulator.

In the UK, Part VII of the Financial Services and Markets Act allows such schemes. The court must be satisfied that, in all the circumstances of the case, it is appropriate to sanction the scheme, based on a skilled person's report on whether clients are adversely affected. Where no such route exists, client consent and confidentiality rules become decisive. When Fibi Bank (Switzerland) sold its banking relationships and clients' assets to CBH, completion was subject to FINMA approval.

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Clarify which legal route applies in each booking centre

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Check what client data may be shared with the buyer before consent

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Build regulatory approvals into the timeline from the start

Which of your clients would have to sign something before their account can move?

Keep in mind: The legal route decides the timeline. A consent-based transfer takes months longer than most business plans assume.

STEP 3

Ask Clients Early

Clients who hear about the transfer from the press or from a competitor are more likely to leave. Tell them early, in plain words: what changes, what stays the same, when it happens and what they need to do. Relationship managers should speak to key clients before any letter is sent.

In the Barclays ring-fencing case, the court required notices to be sent at least 42 days before the hearing, with a dedicated website as the main source of information. The FCA's Consumer Duty sets the standard for the content: firms should help consumers to understand the information they are given and make timely and informed decisions. My article on getting client transfer right in a bank merger shows how to plan one letter per client segment.

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Brief relationship managers before clients are informed

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Send one clear letter per client segment, with dates and actions

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Set up a dedicated hotline and website for questions

Would your clients understand from your first letter what they need to do and by when?

Keep in mind: Every unanswered question becomes a reason to look elsewhere. Publish answers to the most frequent questions before the first letter goes out.

STEP 4

Map Products and Mandates

Every account, product, fee, mandate and power of attorney needs an equivalent at the new bank. Where none exists, decide in advance what the client receives instead and tell them before the move. A discretionary mandate that becomes an advisory one is a change the client must know about.

The new bank also takes on responsibility for advice from the first day. ESMA's suitability guidelines require firms to ensure that client information is reliable and consistent without unduly relying on clients' self-assessment. Use the transfer to update outdated profiles and documents. My article on running a KYC refresh without a backlog shows how to plan the update of outdated files.

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Map every product and fee model to its target equivalent

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Flag clients whose terms will change and contact them first

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Check that KYC and suitability data meets the buyer's standards

How many of your clients hold a product the new bank does not offer?

Keep in mind: Selling and rebuying securities to fit a new product range can trigger taxes for the client. Transfer assets in kind wherever possible.

STEP 5

Run Post-Merger Integration in Waves

A single weekend for all clients leaves no room to learn. Split the book into waves, starting with a smaller group of less complex clients. Rehearse each wave in full beforehand, including reconciliation of every account and position after the move. In a decommissioning project I worked on, we switched off the least critical applications first, so the team had learned from its mistakes before the critical ones.

Rehearsals alone are not enough if they do not test what clients will do. Before its 2018 migration, TSB's board relied on nine successful dress rehearsals and transition events and a pilot with more than 1,600 employees. The data moved correctly, yet the platform failed under real use. The PRA expects banks to test regularly their ability to remain within impact tolerances in severe but plausible scenarios.

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Start with a pilot wave of less complex clients

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Define clear go and no-go criteria for each wave

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Test the new platform under full client load, not only data accuracy

Who in your team would stop a migration weekend at midnight if a check failed?

Keep in mind: A wave plan needs a fallback plan. Agree in advance how to return clients to the old platform if a wave fails.

STEP 6

Watch the First Weeks

The weeks after a move decide whether clients stay. Track logins, failed payments, complaints and call waiting times daily. Fix the most frequent problems first and tell clients what has been fixed.

Fraudsters also use the confusion. After the TSB migration, the bank received over 10,600 fraud alerts and 1,300 customers had money stolen. Warn clients before the move how the new bank will contact them. The FCA expects that ongoing consumer service should be as easy to access as sales. My article on the integration readiness check shows how to plan hypercare after each wave.

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Track complaints, logins and assets transferred out every day

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Warn clients about fraud attempts before and after the move

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Keep extra staff on hotlines for at least the first month

Would you notice within a week if key clients began moving assets out?

Keep in mind: Attrition rarely shows on the first day. Compare assets per client at one, three and six months against the level before the transfer.

We've Stopped Trusting Institutions and Started Trusting Strangers | Rachel Botsman (Associate Fellow @ Saïd Business School, University of Oxford)

SAMPLE CASE

Charles Schwab

In October 2020, Charles Schwab closed its $22 billion acquisition of TD Ameritrade. It then had to move millions of retail and advisor clients onto its own platform. Over five client transition groups in 2023 and 2024, it converted about $1.9 trillion in client assets across more than 17 million accounts.

Each group informed the next. Schwab sent information to affected advisors for about a year and answered more than 15,000 questions in webcasts and information sessions. The final group of about 1.8 million accounts moved in May 2024, after which the TD Ameritrade platforms were closed.

Schwab planned for some clients to leave. It expected attrition of about 4% of Ameritrade's pre-deal revenue, or roughly 1% of combined client assets. By the final wave, a spokesperson said Schwab had comfortably outperformed its expectations for client attrition.

Key takeaway: Schwab moved more than 17 million accounts without a major disruption by splitting the transfer into waves, preparing clients for a year in advance and planning for attrition from the start.

"We may just ask for time sometimes to correct things. Give us a chance to make it right."

Bernie Clark (Head of Schwab Advisor Services @ Charles Schwab)

In Short

In a post-merger integration, transferring clients between banks is not an IT project with a client letter attached. It is a change of relationship for every client, with legal, regulatory and personal consequences.

Banks that define the perimeter, choose the right legal route, inform clients early, map every product and move in rehearsed waves keep more of the book they paid for. The first weeks after the move then show whether clients trust the new bank as much as the old one.

Frequently Asked Questions

Do clients have to agree before their account moves to another bank?

It depends on the legal route. In a consent-based transfer, each client agrees and opens a relationship with the new bank. Some countries, such as the UK, allow a court-approved scheme that moves accounts collectively without individual consent. Clients are notified in advance and may object in court. Client confidentiality rules may also limit what the buyer sees before the transfer.

How long does a client transfer between banks usually take?

A transfer can take from several months to well over a year from signing. The timeline depends on regulatory approvals, the legal route, the number of clients and the complexity of products. Consent-based transfers take longer because every client must respond. Large books usually move in several waves, each with its own rehearsal, review and fallback plan.

How can a bank limit client attrition during a transfer?

Inform clients early through their relationship managers, before letters arrive. Keep advisers and service levels stable, explain any changed terms in plain words and transfer assets in kind to avoid tax costs. After the move, track complaints and asset outflows daily and fix the most frequent problems first. Planning for some attrition from the start also helps to set realistic targets.