How Private Banks Are Underwriting Mortgages in 2025 Using Investment Portfolios & Asset-Based Lending
Investment Portfolios & Net Worth Underwriting — How Private Banks Are Approving High-Value Mortgages in 2025 for Clients With Complex Wealth Structures
Why Traditional Mortgage Underwriting Doesn’t Fit HNW Borrowers
High-net-worth individuals are rarely a neat fit for high street lending. Whether they receive irregular income, hold wealth in investments, or operate across jurisdictions, conventional affordability models often fall short.
In 2025, private banks continue to lead the way in underwriting mortgages based on total wealth, not just taxable income — and investment portfolios are playing a larger role than ever.
🔗 For a full breakdown of how lenders now view high-net-worth profiles, see High Net Worth Mortgages in 2025: What Lenders Look for Beyond Income.
How Private Bank Underwriting Works in 2025
Private banks take a more bespoke, relationship-led approach. Rather than applying blanket affordability rules, they assess the broader financial picture, including:
- Net worth and liquidity
- Discretionary investment portfolios
- Income across trusts, SPVs, or family offices
- Global real estate or business holdings
- Long-term banking or custody relationships
This flexibility allows clients with complex or fluctuating income to secure mortgage funding based on assets, credibility, and repayment strategy — not payslips.
🔗 See how private banks structure finance in How Private Banks Are Underwriting Mortgages in 2025 Using Investment Portfolios.
Using Investment Portfolios as Security
In many cases, borrowers can use investment holdings to support or even secure their borrowing. This includes:
- Pledged portfolios: assets remain invested but are pledged as collateral
- Asset drawdown models: lender assesses portfolio’s yield as de facto income
- Cash sweep facilities: interest or capital gains are used to cover loan payments
- Lombard lending: using liquid investments to secure short-term or bridging finance
Some private banks may even offer reduced interest rates for clients who move assets under management — creating a win-win for both sides.
🔗 For more on this strategy, read How Foreign Currency Income & Liquidity-Based Lending Are Reshaping UK Mortgage Approvals.
When This Strategy Works Best
Portfolio-backed or asset-based lending is especially effective when:
- Income is unpredictable (e.g. bonuses, dividends, distributions)
- The borrower is in a low-tax or no-tax jurisdiction
- There is a need for speed, discretion, or higher LTV
- The client prefers to avoid asset sales that would trigger tax events
- Lending is needed against prime UK residential or investment property
🔗 Buying a luxury property? See How to Finance Luxury Property in the UK: A 2025 Guide for HNW Buyers.
How Willow Private Finance Can Help
We work with a broad panel of private banks, wealth-aligned lenders, and boutique finance providers who understand complex client profiles and value long-term relationships.
We support clients by:
- Packaging applications based on net worth and portfolio performance
- Introducing lending opportunities tied to custody and AUM incentives
- Structuring loan-to-value and repayment terms flexibly
- Coordinating with your wealth manager or accountant to avoid tax leakage
- Navigating cross-border rules, compliance, and risk thresholds
🔗 You may also be interested in
Private Client Finance in 2025: Tailored Lending for Complex Profiles.
🔗 Or explore
Trusts and Property Finance in 2025: Lender Attitudes, Risk Appetite, and What’s Changing.
Whether you’re leveraging investments to purchase a property or refinancing with asset efficiency in mind, we can align the right lender and terms to your goals.
📞 Want Help Navigating Today’s Market?
Book a free strategy call with one of our mortgage specialists.
We’ll help you structure a smarter mortgage using your full financial profile.
About the Author: Wesley Ranger
This article was written by Wesley Ranger, Director at Willow Private Finance. Wesley leads our team of specialist brokers, supporting clients in the UK and internationally. Over his career, he has arranged complex and high-value property finance transactions ranging from bespoke residential mortgages in the hundreds of thousands to structured facilities exceeding £100 million for major developments.
Operating within an FCA-regulated, whole-of-market brokerage, Wesley works closely with clients to design tailored strategies that align with their broader financial goals. His experience spans private banks, specialist lenders, and international financing structures, giving clients a competitive advantage in even the most challenging lending environments.
Important Notice:
Willow Private Finance Ltd is authorised and regulated by the Financial Conduct Authority (FCA No. 588422). The information contained in this article is provided for general guidance and information purposes only and does not constitute personal financial advice. Property finance products are subject to status, affordability, and lender criteria, and may not be suitable for all borrowers. Rates, terms, and product availability can change without notice. You should seek regulated, tailored advice before making any financial decisions. Your home or property may be repossessed if you do not keep up repayments on your mortgage or any other debt secured against it.
