Telephone etiquette

For some (even most) this area would too basic. I will probably be slated to raise this thread.

My staff has been on leave for the past few days and I have been answering the phone. I think I have turned away 2 potential clients through my poor telephone etiquette. First impressions as we all know are so important. Both the callers said they were looking for an accountant. Promised to call back, both the calls were not returned.

Like many I get more than my fair share of spam calls. So the next call I get I don't sound pleasant. I interrupt the callers while they are talking.

For an accountancy practice

• What is good telephone etiquette?
• At what stage should I take client contact details? Name, contact number, email and address

Just bear in mind I used to have a PA who use to take my calls.