## TL;DR

"John Smith" at Acme and "John Smith" at Globex are two people, but name-only matching merges them. Disambiguate with company plus a second signal (email, phone); name alone is never enough for a merge decision. Same name is the start of investigation, not a conclusion.

## Error

```text
(No error; the symptom is two distinct people's records merged into one because the names matched.)
```

## Steps

1. For same-name candidates, compare company (account/domain). Expected: different companies is a strong contra-signal.
2. Require email or phone agreement before merging same-name contacts. Expected: a second confirming signal.
3. If only the name matches, queue for human review; never auto-merge. Expected: no merges on name alone.
4. After a bad merge, unmerge if possible and restore from history. Expected: damage repaired.
5. Encode the rule: name match without company or contact-point match never auto-merges. Expected: the policy prevents recurrence.

## When to use

- Same-name contacts at different companies get merged.
- An agent matches on name only.
- Common names in the dataset.

## When not to use

- Same name at the same company (likely duplicates; different evidence).
- Email-based matching (already disambiguated).

## Tool compatibility

- Contact matching logic in the agent.
- Review queues for ambiguous pairs.

## Variant phrasings

### same name, different company merged

Require company plus a second signal.

### name-only matching

Never merge on name alone.

## Why it happens

Names are not unique identifiers, but they are the most visible field. Matching pipelines that weight name heavily conflate distinct people with common names.

## Edge cases

- People who changed companies legitimately have the same name at two companies over time; check employment dates.
- Name changes (marriage) break even careful matching; email is the stable key.
- Cultural naming patterns produce many identical names; raise the evidence bar accordingly.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_sv9T-vUJeVgsXe7dv-tPnw