Bank Account Aggregation for HNW Individuals: Managing Multiple Accounts Across Jurisdictions

A typical internationally mobile HNW individual might hold accounts at a UK clearing bank, a private bank in Switzerland, a current account in the UAE, a savings account with an Isle of Man offshore provider, an investment account with a London-based stockbroker, and a Cyprus property holding account. Logging into six separate institutions to understand their financial position takes time, creates fragmentation, and makes it nearly impossible to obtain a consolidated real-time view of net worth.

Bank account aggregation addresses this problem. But the tools available vary enormously in sophistication, international scope, and privacy risk. This guide explains the landscape and how to choose the right approach.

What Is Account Aggregation?

Account aggregation is the process of combining account data from multiple financial institutions into a single interface. In its most basic form, this might be a spreadsheet updated manually each week. At the sophisticated end, it involves real-time API connections to multiple banks and investment platforms, automated currency conversion, and adviser-facing reporting dashboards.

The aggregated view typically covers:

• Current account balances and recent transactions
• Savings account balances and accrued interest
• Investment portfolio valuations
• Pension and SIPP values
• Property portfolio estimated values (manually entered or via automated valuation tools)
• Credit card balances
• Loan and mortgage outstanding balances

Aggregation does not move money — it is a read-only view. The underlying accounts remain separate, and all transactions and payments are made through each institution's own interface.

Open Banking Aggregation: UK and Europe

For accounts at UK banks, open banking provides the cleanest and most secure aggregation mechanism. Authorised aggregation providers connect to banks via standardised APIs, with explicit user consent and FCA oversight. You grant permission, and data flows securely without sharing your login credentials.

The main UK aggregation applications with open banking connectivity include:

Moneyhub: One of the most comprehensive UK platforms. Connects to most major UK banks, building societies, pension providers, and investment platforms via open banking. Also supports manual account entry for institutions not API-connected. Used by financial advisers as a client-facing platform. Particularly strong for HNW individuals due to its ability to aggregate property values, investment accounts, and multi-currency balances.

Snoop: More focused on consumer switching and rate comparison, though useful for identifying better savings rates across existing accounts and for transaction categorisation across multiple accounts.

Emma: Popular with younger HNW clients. Strong on subscription tracking and spending analytics.

For European accounts, PSD2 provides equivalent open banking rights across EU member states, though coverage varies by institution and country. Some EU banks have been slower to implement PSD2 connections than their UK equivalents.

Private Bank Consolidated Reporting Platforms

For larger, more complex wealth structures, institutional-grade wealth aggregation platforms offer significantly more functionality than consumer aggregation apps — at a correspondingly higher cost.

SEI: A portfolio management and client reporting platform used by many private banks, family offices, and independent wealth managers. Can aggregate across asset classes, currencies, and jurisdictions. Advisers use SEI to provide clients with consolidated monthly reporting.

Addepar: A data aggregation and analytics platform designed for family offices and wealth managers. Particularly strong for alternative investments, private equity, and real assets — categories that consumer apps do not handle. Used by many of the world's largest family offices.

Masttro: Consolidates investments, banking, real estate, and alternative assets. Used by family offices and wealth managers with HNW clients who have complex, multi-jurisdiction portfolios.

Calastone / InvestCloud: Used more frequently by fund managers and platform providers, but available to sophisticated end-clients through their wealth managers.

These platforms typically require engagement through a wealth manager or family office — they are not direct-to-consumer products. Their advantage is the depth of integration with institutional custodians and their ability to handle non-standard assets.

Manual Aggregation via Spreadsheet

For individuals who are not ready to share data with a third-party application, or whose accounts are predominantly held at non-API-connected international banks, manual aggregation via spreadsheet remains the most privacy-preserving option.

A well-designed spreadsheet aggregation model includes:

• One row per account, with institution, account number (last four digits), currency, and balance
• A separate reference table of currency exchange rates (updated weekly or monthly via a data feed)
• A "functional currency" column that converts all balances to a single currency (typically GBP, USD, or EUR) at the current rate
• A net worth summary calculating total assets, total liabilities, and net position

The limitation is obvious: manual updates are time-consuming, and the view is only as current as the last update. For busy individuals, gaps of weeks or months make the spreadsheet increasingly unreliable.

A practical hybrid approach uses open banking aggregation for UK accounts (automated, real-time) and manual entry for international accounts (monthly update via spreadsheet or into the aggregation app's manual entry feature).

International Account Coverage: The Key Limitation

The most significant gap in consumer aggregation tools is international bank coverage. Open banking as a framework operates within the UK and EU. Banks in the UAE, Singapore, Switzerland, Channel Islands, Isle of Man, Cayman Islands, and most other international private banking centres are not connected to the UK open banking infrastructure.

This means that for many HNW individuals with significant offshore holdings, the most valuable accounts are precisely the ones that cannot be auto-connected.

Workarounds include:

• Manual entry: Most aggregation platforms allow manual balance entry for unconnected accounts
• CSV upload: Some international banks allow transaction export as a CSV file, which can be imported into aggregation platforms
• Adviser platform integration: For clients who use a discretionary fund manager (DFM) or private bank with their own reporting platform, consolidated statements from that platform can supplement the aggregation app
• Screen scraping (with caution): Some older aggregation tools use screen scraping — automated login using your credentials — to access accounts that do not have APIs. This is a fundamentally less secure method, is being phased out by many banks, and should be avoided where possible

Privacy Considerations: What Data Are You Sharing?

Connecting accounts to an aggregation application means sharing financial transaction data with the application provider. The key questions to ask before connecting any account are:

Is the provider FCA-authorised? For UK accounts via open banking, only FCA-regulated providers can legally access your data via the API framework. Check register.fca.org.uk.

How is data stored? Is your transaction data encrypted at rest? Where are the servers located (UK/EU, or elsewhere)? What are the data retention policies?

Who has access? Can employees of the aggregation provider see your transaction data? Under what circumstances?

Is data sold or shared? Some free aggregation apps monetise through anonymised data sharing or targeted financial product recommendations. Review the privacy policy carefully.

Can you revoke access? Any open banking connection can be revoked through your bank's app or website — the consent is yours to withdraw at any time. Verify that revocation is immediate and complete.

OAuth vs credential sharing: Open banking uses OAuth, meaning you never share your bank login password with the aggregation app. If an app asks for your banking password directly, it is not using proper open banking infrastructure and the security risk is significantly higher.

GDPR and Data Subject Rights

Under the UK GDPR, you have rights over your personal financial data that aggregation providers must respect:

• Right of access: You can request a copy of all data held about you
• Right to erasure: You can request deletion of your data (subject to regulatory retention requirements)
• Right to portability: You can request your data in a machine-readable format
• Right to restrict processing: You can limit how your data is used beyond the core service

If you close an account with an aggregation provider, confirm in writing that your historical transaction data is deleted and request confirmation of deletion.

Functional Currency Choice in Consolidated Reporting

For multi-currency aggregators, the choice of "functional currency" — the base currency in which all balances are converted for consolidated reporting — matters. GBP is natural for UK-based individuals. USD is often preferred by those with significant US-denominated assets. EUR may be appropriate for those with primary exposures in the eurozone.

The key is consistency: using the same functional currency over time allows meaningful trend analysis. Switching functional currencies mid-stream distorts historical comparisons significantly.

Revaluation gains and losses — changes in the aggregated value caused solely by exchange rate movements rather than actual gains — should be tracked separately so you understand the drivers of changes in your consolidated net worth.

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This guide is for general information only and does not constitute financial or legal advice. Technology platforms evolve rapidly and availability of specific features may change. Privacy and data protection rights vary by jurisdiction. Seek appropriate professional advice before connecting accounts to third-party aggregation platforms.

How Global Investments Can Help

Global Investments works with HNW clients to design consolidated financial reporting structures that span UK banking, offshore accounts, investment portfolios, and property holdings. We can advise on appropriate aggregation platforms for your complexity level, help establish secure adviser data-sharing arrangements, and provide regular consolidated net worth reporting as part of an ongoing wealth management engagement.

For clients with complex international structures, we offer manual aggregation as part of our quarterly financial review service, ensuring a complete and accurate picture regardless of which accounts can be connected automatically. Contact our team to discuss your specific requirements.