> For the complete documentation index, see [llms.txt](https://guide.scamshield.gov.sg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.scamshield.gov.sg/resources/help-center/call-blocking/does-scamshield-need-caller-id-to-work.md).

# Does ScamShield need caller ID to work?

No, ScamShield only auto-blocks callers based on whether the phone number is blocked in the ScamShield database. This does not include alphanumeric caller IDs, therefore it will not impact you if you choose to opt-out of using caller IDs or caller number displays from your telco.