Merging duplicate people in Family Tree Maker
Open and Family Tree Maker scores every suspected pair out of 1,000. Merge the 1,000s with confidence; check everything below that by hand. And back up first — do not count on undoing a merge.
- Applies to
- FTM 2024 · 2019 · 2017 · 2014
- Platform
- Windows & Mac
- Time
- ~1 hour
Do not rely on undo to rescue a bad merge. Any undo available is limited, and it is widely reported as unreliable after a large merge or once you have carried on working. There is no merge history to roll back through. If you merge a father and his son by mistake, the route back you can actually depend on is the backup you made beforehand. You may have read that merges can be undone — much of that advice is about FamilySearch, a different product with a proper undo-merge feature. Don't let it lull you.
What you're probably seeing
- The same ancestor listed twice in the index, sometimes three times.
- A person with half their sources — the rest are attached to their double.
- Two versions of one couple, each with some of the children.
- Relationship calculations that come out wrong, because the software sees two separate people.
- Charts with a branch that stops abruptly, then reappears elsewhere.
- A tree whose total person count crept up after every sync or import.
Where duplicates come from
Duplicates don't appear on their own — they're created, almost always by one of these. Knowing which applies tells you roughly how many to expect.
| How it happened | Typical scale | How they look |
|---|---|---|
| GEDCOM imported from a relative | Hundreds, sometimes thousands | Whole branches doubled at once |
| Ancestry hints accepted too quickly | A steady trickle | One person at a time, well sourced on both copies |
| Two files merged together | Large | Clustered around the overlap between the trees |
| Same ancestor reached down two branches | A handful | Often genuine pedigree collapse, not an error |
| Manual re-entry after a search failed | Occasional | One copy sparse, the other detailed |
Do this first Back up — this is the one guide where it's non-negotiable
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Go to and tick include media files.
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Save it somewhere outside your Family Tree Maker folder, with today's date in the name.
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Check the file size looks sensible. An 8 KB backup is not a backup. Full detail in backing up properly.
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Plan to merge in one sitting. A backup that covers the whole session is far easier to reason about than several partial ones.
Step 1 — Open Find Duplicate People
The tool It's in the Edit menu, not Tools
This is the most-missed tool in the program, largely because everyone expects it to live under Tools alongside Compact File. It doesn't.
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Open your tree, then choose .
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If you're offered a backup, accept it, even though you've already made one. It costs a minute.
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Let it finish scanning. On a large tree this takes a while — it's comparing every person against every other.
Pairs are listed side by side with a match score. The score is the whole game. Schematic — shows where to look, not a picture of your screen. Layout varies by version.
Step 2 — Read the match score properly
The bit that matters 1,000 means near-identical
The score is Family Tree Maker's confidence that two records describe one person, worked out by comparing names, dates and places. It is a suggestion, not a verdict — and the program has no understanding of family structure, only of matching text.
| Score | What it means | What to do |
|---|---|---|
| 1,000 | Almost exact — names, dates and places all agree | Merge, after a glance at both records |
| High but not 1,000 | Most details agree, one or two don't | Open both. Usually genuine, occasionally two cousins named alike |
| Middling | Name matches, dates or places diverge | Check every fact by hand. This is where mistakes happen |
| Low | Little more than a shared name | Usually two different relatives. Leave alone |
The trap: naming traditions. Families that named the eldest son after his father produce John Whitfield b.1841 and John Whitfield b.1868, same parish, same everything but the year. The tool scores them as a likely match. Merge them and you have destroyed a generation — the grandchildren now hang off the wrong man, and every relationship below is wrong. A differing birth year is a reason to stop, not a rounding error.
Step 3 — Compare, then merge
The merge itself Work top-down and stop when you get tired
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Sort the list so the highest scores are first, and work down. The confident merges get done while you're fresh.
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Select a row and click Compare/Merge to see both records side by side.
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Check three things before confirming: do the parents match, do the spouses match, and do the children overlap? Two records for one person will agree on at least one. Two different people usually won't.
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Where the records disagree on a fact, you're choosing which version survives. Keep the one with a source attached.
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Stop before you're tired. Merging is a judgement call repeated hundreds of times, and errors cluster at the end of long sessions. Half a list done carefully beats a full list done at speed.
Step 4 — The duplicates the tool can't see
Often the worst ones Anything the name matching misses
Find Duplicate People matches on recorded details. Change the details and the duplicate becomes invisible to it — and these are frequently the pairs causing the most damage.
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Married versus maiden surnames. Mary Whitfield and Mary Barnes are the same woman recorded twice. The tool will never pair them. Sort the index by first name and scan.
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Nicknames and abbreviations. Bill and William, Peggy and Margaret, Jno and John in older records.
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Mistyped years. One digit wrong drops the score far enough to hide the pair.
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Spelling variants. Whitfield and Whitfeild, Smith and Smyth — routine in parish registers.
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Work surname by surname rather than trying to hold the whole tree in your head.
Step 5 — If you've merged the wrong people
Recovery Restore, don't unpick
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Stop working immediately. Every further change makes the backup more expensive to go back to.
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Restore the backup to a new file name, then compare it against the current one. See restoring from a backup.
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If there's no backup, you're rebuilding by hand: re-create the second person, then reattach their parents, spouse, children, facts, sources and media individually. It's slow, and some detail is usually lost for good.
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If the merged pair had synced to Ancestry before the mistake, your online tree may still hold the correct structure — see the sync guide before overwriting anything.
If the list is too long to face
Several thousand candidate pairs after a big GEDCOM import is genuinely daunting, and it's the point at which people abandon a tree they've spent decades on. Two honest options:
- Do it in small sessions. Twenty pairs a day, highest scores first. It's slow but it's yours, and you'll learn the family while you do it.
- Or have someone work through it with you. Bulk merging is pattern recognition — the judgement calls repeat, and once the pattern is clear the work goes quickly.
Thousands of duplicates, or a merge gone wrong?
We work through them on a copy of your file, so your original is never at risk — and we can often unpick a bad merge that looks unrecoverable.
Stopping it happening again
- Search before you add. Most manual duplicates come from adding someone who was already there under a slightly different name.
- Slow down on Ancestry hints. Accepting a hint for someone already in your tree is the commonest steady source of duplicates.
- Run Find Duplicate People after every import, while the new arrivals are still fresh in your mind.
- Record maiden names in the surname field. It prevents duplicates and helps the tool find them.
- Merge before syncing, never on both sides at once.
- Check twice a year as routine, alongside compacting the file.
Frequently asked questions
Can I undo a merge in Family Tree Maker?
Not dependably. Any undo is limited, and it's widely reported as unreliable after a large merge or once you've carried on working — and there's no merge history to roll back through. That's why the backup step isn't optional. FamilySearch does have a proper undo-merge feature, which is why you'll find conflicting advice online — different product.
What does the match score mean in Find Duplicate People?
It's a confidence rating calculated from names, dates and places. 1,000 means the records are almost identical and it's normally a genuine duplicate. Lower scores mean fewer details agree — those need checking individually rather than merging on trust. The table above breaks it down.
Why does my tree have duplicate people at all?
They're created, not spontaneous. Importing a relative's GEDCOM, accepting Ancestry hints for someone already present, merging two files, and reaching one ancestor down two branches all produce them. Regularly synced trees accumulate them steadily.
Will merging duplicates delete my sources or photographs?
A correct merge combines sources, facts and media onto the surviving person rather than discarding them. Do review the comparison screen though — where the two records disagree on a fact, you're choosing which version survives.
Should I merge duplicates before or after syncing with Ancestry?
Merge locally first, then sync once the tree is clean. Merging on both sides independently creates conflicts far harder to resolve than the duplicates you started with — and a big sync straight after heavy merging is more likely to stall.
Why does the tool suggest people who are obviously not the same person?
Because it compares recorded text, not family structure. Naming traditions that repeat a name down the generations produce father-and-son pairs with near-identical records — precisely the case where merging costs you a generation.