"...but I don't have an address!"

Following on from the last article on "Does telemarketing need an address?", what happens if you want to use some geographic filters but all the record has is contact, company and a landline?

Looks like we cannot support any geographic filters right?

Actually, the telephone number contains a wealth of information on where it is, so lets look at some specific examples from the UK:

• +44-1908-592534
• 01908-592534

First thing to note is that they look very similar, but one has a "+44" at the start, whereas the other has a "0".

The "+" says that this going to be an international number with the "44" being the international code for the UK.

Awesome, we now know the country that the number belongs too!

The "0" is a bit more tricky, as for the UK it says that you are dialling within the UK (its called the trunk prefix), but this can vary from country to country. You might see the same number written as +44-(0)1908-592534 to indicate the in country dialling. Note that, If you are located in another country, then dialling 01908-592534 is unlikely to connect as numbers within each country vary and this is specific to the UK. While this sounds obvious but we have seen data with multiple countries and people trying to call without the international prefix - but countries are another story 😁

The next part of the number "1908", is the "coverage" of the number, this is also called the STD (Subscriber Trunk Dialling prefix). Internationally this may be called something different, for example area codes in the US, but principally each country follows this pattern.

For UK based numbers, 1908 is a town in the UK called Milton Keynes.

Now we are "cooking with gas" as once we have a town we can get to:

• Latitude and longitude for map push pins (52.038601,-0.757072)
• County (Buckinghamshire)
• Region (South east)
• NHS Heath Authority (South Central)
• Other bits

Nice !

Ok its not a complete address record, but it takes a simple record and adds a lot of details to help with geographic filtering.

Some of the above details are specific to the UK, but almost all countries have a similar structure.

For example the US dialling prefix (area code) 631 relates to New York, or 234 is Ohio.

From this similar details can be derived.

In wrap up, if you only have a landline then you can derive some key geographic details to help with targeting, however if you only have a mobile number then this is not possible as mobile numbers are not tied to specific location.

For some more background and a list of the UK STD codes see the following Wikipedia page:
https://en.wikipedia.org/wiki/List_of_dialling_codes_in_the_United_Kingdom

For the US area codes see the following link:
https://en.wikipedia.org/wiki/List_of_North_American_Numbering_Plan_area_codes