Overflow call answering
Overflow call answering catches the calls your team cannot get to during business hours. Your phones ring as usual, and if nobody answers within a set delay (15 seconds by default on a Telstra mobile) or the line is busy, the call forwards to a Yes AI voice agent that takes the details and sends them through.
Why do calls overflow?
In small and medium businesses, missed daytime calls usually come from a handful of predictable situations:
- one receptionist is already on a call when a second and third come in
- lunch breaks, staff meetings and training days leave the desk empty
- the owner is on a ladder, under a house or driving between jobs
- Monday mornings and the first day after a public holiday bring a backlog
- a promotion, a storm or a news story brings a rush of calls in one afternoon
None of these is a staffing failure. They are peaks that would cost more to staff for than they are worth, and they are the hours an overflow agent is meant to cover.
How overflow routing works on Australian phone systems
Overflow is set up in your phone service, not in the AI agent. The agent simply answers whatever is forwarded to it, so the first job is working out which setting your phone service uses.
| Phone setup | What triggers overflow | How it is set |
|---|---|---|
| Telstra nbn phone line | No answer, or line busy | *61, the destination number and # for no answer; *24 the same way for busy; cancel with #61# or #24# |
| Telstra mobile | No answer, busy, or unreachable | **61* number *11# for no answer, **67* for busy, **62* for unreachable; cancel with ##61#, ##67# or ##62# |
| Hosted PBX or cloud phone system | A ring group or hunt group that nobody answers, or all members busy | The “no answer” or failover destination in the admin portal |
| Microsoft Teams Phone call queue | Overflow, timeout, or no agents signed in | Exception handling settings in the Teams admin centre |
The Telstra codes come from Telstra’s own guides for nbn home phones and mobiles. Other carriers use similar codes, so check your provider’s support page. In a Teams call queue, Microsoft sets the maximum number of waiting calls at 50 by default (adjustable from 0 to 200) and lets the maximum wait run from 0 seconds to 45 minutes; each of these exceptions can redirect the call or disconnect it (Microsoft Learn, setting up a call queue). Redirecting to an outside number may need extra Teams licensing.
How long should phones ring before overflow?
If the delay is too short, staff lose calls they would have answered. If it is too long, callers hang up before the agent picks up. Telstra mobiles accept 15, 20, 25 or 30 seconds, and Microsoft recommends letting each Teams queue member’s phone ring for at least 20 seconds. A delay of 15 to 20 seconds is a sensible starting point; review it after a month of data.
How do you avoid call loops?
If the agent transfers an urgent call back to your office, the destination must be a direct number that does not forward to the agent again. Otherwise the call goes round in a circle until the caller gives up. Test every transfer path before you go live.
Count your missed calls before you switch it on
It is worth knowing the size of the problem first. Most phone systems and carrier portals keep a call log you can export.
- Export two to four weeks of inbound call records.
- Count calls that were not answered, grouped by hour of day and day of week.
- Check how many of those callers left a voicemail, and how many rang back within the hour.
- If you use a hunt group or call queue, look for abandoned calls, where the caller hung up while waiting.
- Match the peaks to what was happening at the time: lunch, school pick-up, Monday mornings, wet weather.
- Set overflow for the hours where missed calls cluster, then run the same report a month later and compare.
If missed calls turn out to be rare, a better voicemail greeting may be all you need. If they cluster at predictable hours, those are the hours to cover first.
What the agent does with an overflow call
The caller has already been ringing for a while, so the agent gets to the point:
- It answers in your business name and explains that the team is on other calls.
- It asks what the caller needs and whether a call back will do.
- It takes the details your rules ask for and reads the phone number back.
- On the Professional plan it can book an appointment directly; otherwise it records a preferred call-back time.
- Anything you have marked urgent is transferred to a nominated person or texted to them.
- The summary arrives as soon as the call ends, so your team can ring back while the caller is still expecting it.
A caller who asks for a particular staff member gets a message passed to that person, not a guess about when they will be free.
Which plan suits overflow?
Overflow happens in business hours, which is what Yes AI’s Starter plan covers: $299 per month ex GST with 500 minutes and email notifications, and a one-off $499 to set up. If you also want SMS alerts, appointment booking or the same agent answering after hours, the Professional plan adds those. Current inclusions are listed on the Yes AI pricing page, and the cost guide shows how to estimate minutes.
Forwarded calls may cost extra on some phone plans. Telstra’s mobile support page says call forwarding is included in plans with an unlimited call allowance, so check your own plan before you set it up.
Limits
- Forwarding has to be set correctly in your phone service. A wrong code sends calls to the old voicemail box instead of the agent.
- The agent cannot see your team’s diary unless it is connected to your booking or practice system.
- Callers who want to complain or who are upset are better handed to a person promptly. Write a rule for it rather than leaving it to chance.
For covering nights as well as busy days, see 24 hour call answering. Small teams choosing between plans can read after hours answering for small business, and voicemail vs an answering service compares the two options directly. To hear an overflow call handled with your own business details, request a demo.