Make sure at least one source contains both identities together, typically a login or checkout event with ECID and email or CRM id. Normalise identity values (trim and lower-case email) before ingestion. Check that each identity field uses the intended namespace. Use a merge policy that includes the datasets involved, then preview the merged profile for a known customer.

Error Library / AEP

Identity resolution: the same customer shows up as separate profiles

What you seeA customer who is in both CRM and web data appears as two profiles instead of one

Profiles only combine when records share identities that link together in the identity graph. The merge policy then decides which dataset wins when the combined records disagree; it can't join records that have no identity in common.

Why it happens

The web data only carries an anonymous ECID and the CRM data only an email, and no record ever contains both, so nothing links them.
The same person uses different values across systems (for example upper- vs lower-case email).
A custom namespace was created, but no schema actually uses it on an identity field.

How to fix it

Make sure at least one source contains both identities together, typically a login or checkout event with ECID and email or CRM id.
Normalise identity values (trim and lower-case email) before ingestion.
Check that each identity field uses the intended namespace.
Use a merge policy that includes the datasets involved, then preview the merged profile for a known customer.

Before and after

Fails

web: { ECID: A } · CRM: { Email: x@y.com } — nothing links them

Works

login event: { ECID: A, Email: x@y.com } links web and CRM

Common questions

Is this the merge policy's fault?

Usually not. Merge policies choose between values; linking comes from shared identities.

Practise the fix

Resolve Identities Across Sources

Reproduce this error in your own AEP practice workspace, fix it, and earn a verifiable credential for the skills involved: Custom identity namespaces, Merge policies, Cross-source identity resolution, Merged profile validation.

See the Lab plan

Related errors

XDM error: field "expected type object but got string" (ECID, identityMap)

Can't enable a schema for Real-Time Customer Profile: no primary identity

AdsBot is an independent training provider, not affiliated with Adobe. Behaviour can differ between ingestion methods and product versions; always test with a small batch first.