Legacy fundraising is a long game, and that makes it hard to measure.
You won’t see results for years. The people pledging legacies today won’t pass away for a decade or more. The income arriving this year comes from relationships built ten years ago. Your board wants to know what legacy fundraising is worth, but you can’t give them a straight answer because the pipeline is invisible and the timeline is unpredictable.
So most charities either don’t measure legacy fundraising properly or they measure the wrong things. They track cash received this year, which tells them nothing about the programme they’re building now. They count pledges without considering when those gifts might actually arrive. They set targets based on wishful thinking rather than evidence.
This guide shows you how to measure legacy fundraising in ways that actually matter, and how to forecast future income with enough accuracy to inform real decisions.
Why Legacy Fundraising Measurement Is Different
Most fundraising channels deliver results quickly enough to measure cause and effect. You send a direct mail appeal and donations arrive within weeks or you run a digital campaign and conversions happen within days.
Legacy fundraising doesn’t work like that. The lag between activity and income is so long that traditional ROI calculations fall apart. You might spend money on legacy marketing today and not receive a single gift for five years.
This doesn’t mean legacy fundraising can’t be measured. It means you need different metrics that reflect the unique timeline and characteristics of the channel. You’re measuring pipeline health, future value, and long-term trajectory.
The Metrics That Actually Matter
1. Legacy Pledges Received
This is your primary leading indicator. Every pledge represents future income, even if you don’t know exactly when it will arrive or how much it will be worth.
Track the number of new legacy pledges you receive each year. This tells you whether your programme is growing, stable, or declining. If pledges are increasing year on year, your programme is healthy. If they’re flat or falling, you have a problem that won’t show up in your cash income for years.
Don’t just count pledges. Segment them by type: residuary legacies (percentage of estate), pecuniary legacies (fixed sum), and specific legacies (particular items). Residuary legacies are usually the most valuable.
2. Pipeline Value
Your pipeline is all the legacy pledges you currently hold. Pipeline value is the estimated total income from those pledges.
This is hard to calculate because most pledgers don’t tell you the value of their gift, and even when they do, estate values change over time. But you can estimate using average legacy gift values from your charity or sector benchmarks.
If your average legacy gift is £50,000 and you have 100 pledges in your pipeline, your estimated pipeline value is £5 million. That’s the future income you’re stewarding.
Track pipeline value over time. It should grow as you add new pledges and as estate values increase. If pipeline value is shrinking, you’re losing pledges faster than you’re gaining them.
3. Conversion Rate
How many of the people you approach about legacy giving actually pledge?
If you have meaningful conversations with 100 supporters and 5 pledge, your conversion rate is 5%. This tells you how effective your messaging and approach are.
Track conversion rates by channel. Face-to-face conversations usually convert better than direct mail. Conversations with long-term supporters convert better than cold approaches.
4. Pledge Retention Rate
Not all pledges stay in your pipeline. People change their wills, their circumstances change, or they pass away sooner than expected.
Pledge retention rate tells you what percentage of pledgers remain in your pipeline over time. Of the pledges you received five years ago, how many are still active?
Good stewardship improves retention rates. Poor stewardship damages them. If you’re losing pledges at high rates, your stewardship programme needs work.
5. Legacy Income Received
This is actual cash that arrived this year from legacy gifts. It’s a lagging indicator because it reflects work done years ago, but it’s still important.
Track total legacy income annually and compare it to previous years. Look for trends over five to ten year periods rather than year-on-year changes, because legacy income is volatile and single large gifts can distort annual figures.
6. Average Gift Value
What’s the average value of legacy gifts your charity receives? Calculate this over multiple years to smooth out volatility. A single £1 million gift can skew a single year’s average, but averaged over five or ten years, you get a more reliable figure.
Track average gift value separately for residuary and pecuniary legacies, because residuary gifts are typically much larger.
How to Forecast Future Legacy Income
Forecasting legacy income is part science, part educated guessing. You’ll never be perfectly accurate, but you can get close enough to inform planning and investment decisions.
Method 1: Pipeline-Based Forecasting
Start with your current pipeline value. If you have £5 million in estimated pledges and your average time to realisation is 10 years, you might forecast receiving roughly £500,000 per year over the next decade.
This is simplistic because gifts won’t arrive evenly and estate values will change, but it gives you a baseline.
Adjust for attrition. If your pledge retention rate is 80%, reduce your pipeline value by 20% before forecasting. Adjust for growth by factoring in new pledges you expect to receive.
Method 2: Historical Trend Forecasting
Look at legacy income over the past 10-15 years. Plot the trend line and extend it forward.
If your legacy income has grown at 5% per year for the past decade, forecasting 5% annual growth for the next five years is reasonable, assuming you maintain current investment levels.
This method works well for mature legacy programmes with stable performance.
Method 3: Activity-Based Forecasting
If you know your conversion rate and you plan to have legacy conversations with a certain number of people, you can forecast pledge acquisition.
Planning to approach 200 supporters next year with a 5% conversion rate? You’ll likely gain 10 new pledges. At an average gift value of £50,000, that’s £500,000 in future pipeline value.
Combining Methods
The most robust forecasts use all three methods. Your pipeline tells you what’s already committed. Historical trends tell you what’s realistic based on past performance. Activity forecasts tell you what new investment might generate.
Use all three to create a range: best case, likely case, and worst case scenarios. Present the range to your board rather than a single figure, because legacy income is inherently unpredictable.
Common Measurement Mistakes
Focusing Only on Cash Received
Legacy income received this year tells you almost nothing about the effectiveness of your current programme. That income reflects work done five to fifteen years ago.
If you only measure cash received, you won’t spot problems until years after they’ve started. Measure leading indicators (pledges, pipeline value, conversion rates) alongside lagging indicators (cash received).
Not Segmenting by Gift Type
Lumping all legacy income together hides important patterns. Residuary legacies behave differently from pecuniary legacies. Segment your data to understand what’s actually happening.
Comparing Year-on-Year
Legacy income is volatile. One large gift can make a year look exceptional. The absence of large gifts can make a year look terrible. Neither tells you much about underlying programme health.
Always look at multi-year trends rather than single-year changes.
Ignoring Unknown Pledges
Many legacy gifts arrive as surprises from people who never told you they’d included you in their will. These can represent 50% or more of your legacy income.
You can’t forecast unknown pledges precisely, but you can estimate based on historical patterns. If 50% of your legacy gifts have historically been surprises, factor that into your forecasting.
The Bottom Line
You can’t manage what you don’t measure, but legacy fundraising requires different metrics than other channels.
Stop obsessing over cash received this year and start tracking the indicators that tell you whether your programme is healthy: pledges coming in, pipeline growing, conversion rates improving, retention rates holding steady.
Forecast future income using your pipeline, historical trends, and planned activity. Present ranges rather than precise figures. Be honest about uncertainty.
Good measurement won’t eliminate the long timeline or the unpredictability of legacy fundraising, but it will give you the data you need to make the case for investment, plan strategically, and demonstrate that legacy fundraising works.
Even when the results won’t show up for another decade.
Want to go deeper? Read our Complete Guide to Legacy and In-Memory Fundraising for comprehensive strategies on building programmes that work.
Need expert guidance? Join Fundraising Everywhere as a member for access to the Legacy & In-Memory Conference, workshops on measurement and forecasting, and a community of fundraisers working on the same challenges. Learn more about membership