# Difficulty detecting duplicate Contacts

**URL:** <https://community.hubspot.com/t/difficulty-detecting-duplicate-contacts/126587>\
**Category:** APIs & Integrations\
**Tags:** contacts\
**Created:** [February 21, 2025, 3:31pm UTC](https://community.hubspot.com/t/difficulty-detecting-duplicate-contacts/126587 "2025-02-21T15:31:26Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![PTSergio](https://avatars.discourse-cdn.com/v4/letter/p/2bfe46/32.png) [@PTSergio](https://community.hubspot.com/u/PTSergio)\
**Post date:** [February 24, 2025, 9:42am UTC](https://community.hubspot.com/t/difficulty-detecting-duplicate-contacts/126587/3 "2025-02-24T09:42:03Z")

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Thanks for the reply - sadly this setup doesnt quite work for me as basically I have batches of 100 email addresses. I am using the search API to find email addresses using the IN filter, but this only searches the primary email.

If I also want Contacts via their hs\_additional\_emails field I have to supply more filters where the field CONTAINS the email. Due to the limitations of the API I can’t really constructs the query I need - unless I am doing it wrong.

For simplicity, imagine you have 1000 users on your system - how do you find them in batch using the API? You need to search both the email field and the additional email comma separated list.

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