The most common and most likely answer to this crossword clue is the 4 plus 4 letter word AREA CODE
I've seen this crossword clue in The Times
A
R
E
A
C
O
D
E
More clues leading to the result AREA CODE
- One used to call a contact, briefly, before work
- Adore ace composition: first part of number?
- Are current lines and numbers entered first?
- What US long-distance caller uses to explain formerly ringing a company
- Opening digits America’s used with most of communication lines?
- Regional legislation figures given in communication
- A key prefix to a telephone number
- Zone rule for ZIP or PIN, say
- ZIP or PIN, for example, of arcade built around end of avenue and circle
Buddy explains!
The straight part
We know that "One used to call" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case one used to call = area code.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.