The most common and most likely answer to this crossword clue is the 8 letter word INTERCOM
I've seen this crossword clue in The Times
I
N
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E
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M
More clues leading to the result INTERCOM
- In meantime firm must replace current phone system
- Method of calling painter comparing exhibits
- Coin term for recirculation blower?
- Organised crime not building telephone system
- Means to communicate in period without company
- Cremation: not a bad way to communicate
- Some painter compromised means of exchange in block?
- Temporary officer replacing a single means of exchange?
- Meantime, I make way for firm’s in-house phone system
- Many birds will be flying south with wing
Buddy explains!

The straight part
We know that "phone system" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case phone system = intercom.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.
What does INTERCOM mean?
INTERCOM noun- An electronic communication system, especially one between rooms in a building