# Caller ID

**URL:** <https://boards.straightdope.com/t/caller-id/333389>\
**Category:** Factual Questions\
**Created:** [November 30, 2005, 3:55pm UTC](https://boards.straightdope.com/t/caller-id/333389 "2005-11-30T15:55:58Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\
**Post date:** [November 30, 2005, 3:55pm UTC](https://boards.straightdope.com/t/caller-id/333389/1 "2005-11-30T15:55:58Z")

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How do telemarketers block their ID? I ask this, because they appear different on my display than an ordinary subscriber who has asked the telco to block their ID. For instance, my mother in law has her name and number blocked from viewing on caller ID. When she calls, it says BLOCKED CALL. But recently I have received telemarketing calls that appear as UNKNOWN CALLER.

Does the phone company treat them differently? Can I depend on all normal subscribers with blocked numbers to appear the same? Or is the caller ID message different depending on the telco of origin?

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**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\
**Post date:** [November 30, 2005, 5:00pm UTC](https://boards.straightdope.com/t/caller-id/333389/2 "2005-11-30T17:00:38Z")

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It might have to do with them being outside your area, possibly not even in the same country. I see job ads for English-speaking telemarketers here in Montreal, presumably so they can hassle Americans at dinnertime.

It’s revenge for the Fenians, I figure.

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**Author:** ![mint\_my\_own](https://avatars.discourse-cdn.com/v4/letter/m/e99b99/32.png) [@mint\_my\_own](https://boards.straightdope.com/u/mint_my_own)\
**Post date:** [November 30, 2005, 5:48pm UTC](https://boards.straightdope.com/t/caller-id/333389/3 "2005-11-30T17:48:12Z")

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In general, if you call from a phone number with extensions you will get that.  
The pbx’s are made by various companies, but most have a general block on outgoing numbers.  
They don’t want you to use call return because you can’t reach the extension but the front desk. And then you would always be asking “Well, \*somebody \*called me from your company and I’m returning the call.” Who would they direct your call to?