The legacy pledge
Rees Calder · 1 May 2026 · 7 min read
The average UK legacy gift is £46,000. That's more than most people donate in their entire lifetime of regular giving. And it costs the donor precisely nothing while they're alive. You keep every penny until you die. Then a percentage of your estate goes to the charity or charities you've chosen. Your family gets the rest. Nobody loses.
Legacy giving in the UK totals over £4 billion per year (Legacy Foresight, 2024), making it one of the largest funding channels for the charity sector. The Remember A Charity consortium estimates that if the proportion of people leaving charitable legacies rose from the current 6% to 10%, it would generate an additional £1 billion annually. That shift requires no new wealth creation. Just more people writing a line in their will.
The mechanics
Residuary legacy. You leave a percentage of your estate (after debts, expenses, and specific gifts) to charity. This is the most common and usually the most flexible form. If your estate grows, the charity benefits proportionally. If it shrinks, your family isn't squeezed. A 10% residuary legacy from a £500,000 estate is £50,000. From a £200,000 estate, it's £20,000. The percentage stays fixed. The amount adjusts.
Pecuniary legacy. A fixed sum (e.g., "I leave £10,000 to the Against Malaria Foundation"). Simple and clear, but inflation erodes the value over time. A £10,000 legacy written in 2026 will be worth substantially less in real terms if you die in 2060.
Specific legacy. A named asset: shares, property, a particular bank account. Less common for charitable giving but can be tax-efficient if the asset has appreciated significantly.
The inheritance tax angle. In the UK, estates over the nil-rate band (currently £325,000, or £500,000 including the residence nil-rate band) pay 40% inheritance tax. But if you leave at least 10% of your net estate to charity, the inheritance tax rate drops to 36%. This means the charitable gift partially pays for itself through tax savings. On a £1 million estate, leaving £100,000 to charity (10%) reduces the IHT rate from 40% to 36%, saving roughly £24,000 in tax. The effective cost of the £100,000 legacy is £76,000. Your beneficiaries lose less than the charity gains.
The Giving What We Can legacy pledge
Giving What We Can, the effective giving pledge organisation, offers a specific legacy pledge alongside their standard 10% income pledge.
The pledge. Commit to leaving at least 10% of your estate to effective charities. The pledge is not legally binding (it's a statement of intention, not a will), but it signals commitment and connects you to a community of like-minded donors. Over 500 people have taken the GWWC legacy pledge as of 2024.
Why it matters for effective giving. Most legacy giving goes to charities the donor has a personal connection with: their local hospice, their university, a disease that affected their family. These are perfectly reasonable choices, but they're rarely the most impactful per pound. The GWWC legacy pledge specifically directs donors toward evidence-based charities, potentially channelling significant wealth toward the most cost-effective interventions.
The numbers. If 500 legacy pledgers each leave an average estate of £400,000 and honour their 10% pledge, that's £20 million directed to effective charities. If the movement grows to 5,000 pledgers (plausible given GWWC's growth trajectory), that's £200 million. Legacy pledges are patient capital, arriving over decades, but the cumulative impact is enormous.
Why so few people do it
Only 6% of UK adults who have a will include a charitable legacy (Remember A Charity, 2024). The gap between "would consider it" and "have done it" is vast.
The will gap. Roughly 54% of UK adults don't have a will at all (2024 survey data). You can't leave a charitable legacy without a will. The single biggest intervention for increasing legacy giving might simply be getting more people to write wills.
Procrastination. Even among those with wills, adding a charitable provision requires updating the document. Most people write a will once and never touch it again. The psychological barrier isn't objection to the idea; it's the activation energy of making a phone call to a solicitor.
Family guilt. Many people feel that leaving money to charity reduces their family's inheritance. The IHT reduction partially addresses this financially, but the emotional calculation is different. The framing matters: "I'm giving away your inheritance" feels like theft. "I'm leaving 90% to you and 10% to save lives" feels like generosity. Same action, different frame.
Lack of prompting. Solicitors rarely ask about charitable legacies when drafting wills unless specifically instructed. The Remember A Charity campaign has been working with the legal profession to make the conversation standard, but progress is slow.
How to do it
Option 1: Include it in a new will. If you don't have a will, get one. Online will services (Farewill, Guardian Angel, Which? Wills) start from £90-150. Tell the drafter you want to include a charitable legacy. Specify the charity name, registered charity number, and percentage or amount.
Option 2: Add a codicil. If you already have a will, a codicil (amendment) can add a charitable legacy without rewriting the entire document. Costs roughly £50-100 through a solicitor, or free through some charity-sponsored will schemes.
Option 3: Free will schemes. Many charities offer free will-writing services in exchange for the hope (not obligation) that you'll include them as a beneficiary. The Remember A Charity consortium coordinates Free Wills Month (October and March). National Free Wills Network provides free simple wills year-round for people aged 55+. These are legitimate professional will services, not charity traps.
What to specify. For effective giving, name the charity precisely. "The Against Malaria Foundation, registered charity number 1105319" is unambiguous. "A malaria charity" invites confusion. If you want your legacy to go to whichever effective charities are recommended at the time of your death (which might be decades away), you can leave the legacy to GiveWell's recommended funds or to Giving What We Can, which will direct the funds to their current top recommendations.
The time value argument
Some effective giving advocates argue against legacy giving on timing grounds: money given now saves lives now, and people in extreme poverty shouldn't have to wait for you to die.
The counterargument. Legacy giving doesn't reduce current giving for most people. The money comes from accumulated wealth at death, not from the annual giving budget. Someone who gives 10% of income during their lifetime AND leaves 10% of their estate to charity is doing both. The legacy pledge is additive, not substitutive.
The uncertainty argument. The best giving opportunities might be different in 30 years. True. But the legacy can be directed to organisations that make allocation decisions (GiveWell's Maximum Impact Fund, GWWC), not to specific programmes. This delegates the "where" decision to the people with the best information at the time of distribution.
The compound argument. Wealth held and invested during your lifetime grows. A £50,000 legacy from someone who dies at 85 may have originated as £15,000 in savings at age 50. The compound growth happened because the money stayed invested. Earlier donation would have been less money, even accounting for the time value of lives saved.
One sentence
Adding a charitable legacy to your will costs nothing during your lifetime, qualifies for inheritance tax reduction, and could be the largest single donation you ever make. It takes one conversation with a solicitor or one update to an online will.
Sources used: Legacy Foresight UK legacy giving market data and projections (2024), Remember A Charity consortium statistics on legacy giving rates and solicitor engagement (2024), HMRC inheritance tax rates and charitable legacy IHT reduction rules (2024-25), Giving What We Can legacy pledge data and methodology (2024), Institute of Legacy Management average legacy gift data (2024), National Free Wills Network and Free Wills Month programme details (2024), Farewill and Guardian Angel online will service pricing (2024). Full links in the planning doc.