Buy Borrow Die Strategy: How the Ultra Rich Use Debt to Pay Almost No Tax
Elon Musk paid an effective federal tax rate of just 3.27% between 2014 and 2018 despite his wealth growing by almost $14 billion according to a ProPublica investigation published in 2021. He did not do that by hiding money offshore. He did it by borrowing against his assets instead of selling them. The buy borrow die strategy is how the wealthiest people in the world access enormous amounts of cash without triggering capital gains tax and once you understand how it works you will never look at debt quite the same way again.
What the Buy Borrow Die Strategy Actually Is
The name sounds complicated but the mechanics are straightforward. You buy appreciating assets. You borrow against them instead of selling them to access cash. When you die your heirs inherit the assets, potentially with a reduced capital gains liability depending on how the estate is structured. That is the whole thing.
The crucial point is that loans are not income. HMRC does not tax you on money you borrow according to HMRC’s published guidance on income and capital gains. So if you have a portfolio worth £10 million that has doubled in value from £5 million, selling it would trigger capital gains tax on the £5 million profit. Borrowing against it triggers nothing. The money lands in your account and HMRC sees nothing taxable because there is nothing taxable to see.
This is not a loophole in the way most people use that word. It is the system working exactly as it was designed. Borrowing money has never been a taxable event in the UK and that is not going to change overnight.
The Three Steps Broken Down
Buy. Wealthy individuals accumulate appreciating assets. Shares in private and public companies, investment property, business equity, fine art. The key is that these assets grow in value over time without being sold, which means no capital gains tax is triggered while you hold them.
Borrow. Instead of selling assets to fund their lifestyle they take out loans using those assets as collateral. Private banks in London routinely offer portfolio backed lending facilities to high net worth clients. The interest rate on these loans is typically lower than the expected growth rate of the underlying assets, which is what makes the whole thing financially rational rather than just a tax trick.
Die. When the asset holder dies, the estate planning that has been put in place, often through trusts or family holding structures, manages how the assets and liabilities transfer. In the UK, assets passed to a spouse are exempt from inheritance tax according to HMRC. Assets left to others benefit from the nil rate band and potentially the residence nil rate band. The combination of careful estate structuring and the absence of capital gains tax on death in many scenarios creates significant tax efficiency at the point of transfer.
A Real Example With Actual Numbers
Say you bought £1 million worth of shares in a business ten years ago. Those shares are now worth £5 million. You need £500,000 to fund a property purchase.
Option one is to sell £500,000 worth of shares. After deducting your original cost the gain is roughly £400,000. Capital gains tax at 24% for a higher rate taxpayer in 2024/25 according to HMRC costs you £96,000. You receive £404,000 in cash.
Option two is to borrow £500,000 against the shares using a portfolio lending facility. You receive £500,000 in cash and pay no tax. Your shares remain intact and continue growing. You pay interest on the loan, but if your shares are growing at 8% per year and the loan costs you 4%, you are still net positive on the underlying asset while accessing the liquidity you needed.
The difference in outcome between those two options is £96,000 kept in your pocket rather than sent to HMRC. On larger sums the numbers become extraordinary.
The Buy Borrow Die Strategy in the UK Context
This is discussed most often in the context of American billionaires but it is very much a UK strategy too. London’s private banks including Coutts, Julius Baer and various Swiss private banking operations offer portfolio-backed lending and real estate credit lines to UK based high net worth clients according to their published wealth management services. UK tech founders, property developers and family offices use these structures regularly.
The difference between the UK and US version is mostly in the estate planning mechanics. The US has a step up in cost basis on death which makes the strategy particularly powerful there. The UK does not have the same rule but the combination of spousal exemptions, nil rate bands, business property relief for qualifying assets and trust structures can achieve significant tax efficiency according to HMRC inheritance tax guidance.
What Are the Real Risks
This is not risk free and anyone who tells you otherwise is not being straight with you.
If your assets fall in value significantly the lender may issue a margin call, demanding additional collateral or partial repayment immediately. In a market crash when your portfolio is down 40% and the bank is calling in security, the position can unwind quickly and painfully.
Interest rates matter too. These strategies work when borrowing costs are well below your asset growth rate. When rates rise sharply, as they did in 2022 and 2023, the margin between your borrowing cost and your investment return narrows or disappears. The Bank of England base rate rose from 0.1% in late 2021 to 5.25% by August 2023 according to Bank of England data.
There is also regulatory risk. Several governments including in the US have discussed taxing unrealised gains, which would fundamentally change the appeal of this strategy. Nothing has been implemented in the UK yet but it is worth monitoring.
Can Ordinary People Use Any of This
The full buy borrow die strategy requires significant assets to be viable. Most private banks require a minimum investable portfolio of £1 million or more before they will offer portfolio backed lending facilities. But the underlying principle, borrowing against assets at a lower cost than the expected return rather than selling and triggering tax, applies at smaller scales too.
An offset mortgage lets you use savings to reduce the interest on your mortgage rather than paying tax on savings income. A director’s loan from your own limited company lets you access company cash without triggering income tax or national insurance in the way a salary would, subject to HMRC rules on director’s loans under Section 455 of the Corporation Tax Act 2010. A stocks and shares portfolio line of credit is available through some online brokers for UK investors.
None of these are the same as borrowing £50 million against a private equity stake. But they are the same principle applied at a scale that is relevant to people building something real with their money rather than waiting until they are already worth nine figures to start thinking about tax efficiency.
Buy Borrow Die Strategy: Questions Worth Answering
Is the Buy Borrow Die Strategy Legal in the UK?
Yes. Borrowing against assets is not a taxable event according to HMRC and has never been one in the UK. The strategy uses the tax system exactly as it was designed rather than exploiting any loophole. That said, HMRC does scrutinise arrangements that appear to have no commercial purpose beyond tax avoidance, so how estate planning and trust structures are set up matters. Proper legal and tax advice is essential at any meaningful scale.
Do You Have to Pay Tax on a Loan in the UK?
No. Loans are not income and are not subject to income tax or capital gains tax according to HMRC guidance. You do pay tax on any interest payments you receive as a lender, and you pay income tax if your employer provides a beneficial loan below the official rate. But borrowing money yourself from a bank or lender does not create a tax liability.
What Is Portfolio Backed Lending and Where Can You Get It in the UK?
Portfolio backed lending is a facility where you use your investment portfolio as collateral to borrow money without selling any of the underlying assets. In the UK it is offered by private banks including Coutts, Barclays Wealth and various international private banking operations to clients with significant investable assets. Some online brokers including Interactive Brokers offer margin lending facilities to retail investors at lower asset thresholds, though these come with their own risks and are structured differently to private banking facilities.
Start Thinking About This Now Not Later
Most people learn about strategies like buy borrow die when they are already wealthy enough that it feels like it applies to someone else. The better approach is to understand the principle now while you are still building, because the habits and structures you put in place early, how you hold assets, whether you use a limited company, how you think about debt and liquidity, shape what is possible later.
You do not need to be borrowing against a £10 million portfolio to benefit from thinking like this. You just need to stop treating all debt as bad and start asking whether borrowing against a growing asset is smarter than selling it and handing the difference to HMRC.
Iceburg Wealth does not provide regulated financial advice. Everything here is based on personal experience and research. Always do your own due diligence before making any financial decisions.