Destination, prefix lookup via Phone number - Excel - excel

Question

I have two tables.
Table one contains: phone number list
Table Two contains: prefix and destination list
I want look up prefix and destination for phone number.
Given below Row data table and result table
Table 01 ( Phone Number List)
Phone Number
------------
12426454407
12865456546
12846546564
14415332165
14426546545
16496564654
16896546564
16413216564
Table 02 (Prefix and Destination List)
PREFIX |COUNTRY
-------+---------------------
1 |Canada_USA_Fixed
1242 |Bahamas
1246 |Barbados
1268 |Antigua
1284 |Tortola
1340 |Virgin Islands - US
1345 |Cayman Island
144153 |Bermuda-Mobile
1473 |Grenada
1649 |Turks and Caicos
1664 |Montserrat
Table 03 (Result)
Phone Number | PREFIX | COUNTRY
--------------+--------+-------------------
12426454407 | 1242 | Bahamas
12865456546 | 1 | Canada_USA_Fixed
12846546564 | 1284 | Tortola
14415332165 | 144153 | Bermuda-Mobile
14426546545 | 1 | Canada_USA_Fixed
16496564654 | 1649 | Turks and Caicos
16896546564 | 1 | Canada_USA_Fixed
16643216564 | 1664 | Montserrat

Answer 1

Lets assume phone numbers are in column A, now in column B you need to extract the prefix. Something like this:
=LEFT(A1, 4)
However your Canada_USA_Fixed creates problems as does the Antigua mobile. I'll let you solve this issue yourself. Start with IF statements.
Now that you have extracted the prefix you can easily use VLOOKUP() to get the country.

Answer 2

Assuming that the longest prefix is 6 digits long you, can add 6 columns (B:G) next to the column with the phone numbers in table 1 (I assume this is column A). In column B you'd show the first 6 characters using =LEFT(A2,6), in the next column you show 5 chars, etc.
Then you add another 6 columns (H:M) , each doing a =MATCH(B2,Table2!A:A,0) to see if this prefix is in the list of prefixes.
Now if any of the 6 potential prefixes match, you'll get the row number of the prefix - else you'll get an #N/A error. Put the following formula in column N: {=INDEX(H2:M2,MATCH(FALSE,ISERROR(H2:M2),0))} - enter the formula as an array formula, i.e. instead of pressing Enter after entering it, press Ctrl-Shift-Enter - you'll see these {} around the formula then, so don't enter those manually!.
Column N now contains the row of the matching prefix or #N/A if no prefix matches. Therefore, put =IF(ISNA(N2,'No matching prefix',INDEX(Table2!B:B,N2)) in the next column and you'll be done.
You could also the above approach with less columns but more complex formulas but I wouldn't recommend it.

Answer 3

I'm also doing longest prefix matches and, like everyone else that Google has turned up, it's also for international phone number prefixes!
My solution is working for my table of 200 prefixes (including world zone 1, ie. having 1 for US/Canada and 1242 for Bahamas, etc).
Firstly you need this array formula (which I'm going to call "X" in the following but you'll want to type out in full)
(LEFT(ValueToFind,LEN(PrefixArray))=PrefixArray)*LEN(PrefixArray)
This uses the trick of multiplying a logical value with an integer so the result is zero if there's no match. You use this find the maximum value in one cell (which I'm calling "MaxValue").
{=MAX(X)}
If MaxValue is more than zero (and therefore some sort of match was found), you can then find the position of the maximum value in your prefix array.
{=MATCH(MaxValue,X,0)}
I've not worried about duplicates here - you can check for them in your PrefixArray separately.
Notes for neophytes:
PrefixArray should be an absolute reference, either stated with lots of $ or as a "named range".
I'm assuming you'll make ValueToFind, MaxValue and the resultant index into PrefixArray as cells on the same row, and therefore have a $ against their column letter but not their row number. This allows easy pasting for lots of rows of ValueToFind.
Array formula are indicated by curly braces, but are entered by typing the text without the curly braces and then hitting Ctrl-Shift-Enter.