Managing overflow calls and after-hours call routing

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An overflow call is a call that cannot currently be taken by any agents or
answered by voicemail. This can happen for the following reasons:


All agents are offline.
All agents decline an incoming call.
All agents miss an incoming call.
The maximum queue wait time is exceeded.
The maximum queue size is reached.


This article describes options for managing overflow and after-hours calls, including the
following topics:

Handling overflow calls with omnichannel routing
About adding an
overflow number to a Zendesk number
Adding an overflow
number (for phone lines)
Adding an overflow number (for digital and SIP-IN lines)
Adding an overflow
number when business hours are configured (for phone lines)
Adding an overflow
number when business hours are configured (for digital lines)


Note: Outbound calls cannot be made from toll-free numbers. Therefore, these numbers can't be
used as an overflow number.

Handling overflow calls with omnichannel routing
When you turn on
omnichannel routing, you can configure an
overflow behavior by creating custom queues. Within each custom queue, admins
can define primary and secondary groups. Omnichannel routing will route calls to the
primary groups first, treating them as a single collective pool of agents, and
"overflow" to the pool of secondary groups only when necessary. Although you can
still overflow to alternative numbers, when using omnichannel routing queues, it
isn't necessary because the overflow behavior happens between the primary and
secondary groups of agents configured for the queues.
For more information, see Understanding how omnichannel routing uses queues to route work
to agents and Creating custom omnichannel routing queues.


About overflow phone numbers for Zendesk lines
When you aren't using omnichannel routing, you can provide a better experience for
callers by adding an overflow phone number to each phone line you've added.
When a call is not answered by an agent, and voicemail is off, the call will be sent
to the overflow number. This could be the number of an external support
organization, or an on-call agent that you use outside of your normal
business-hours, or during holidays.
Things to consider when you set up an overflow number include:

When a call is sent to an overflow number that is not a Zendesk number, a ticket
is created with the tag, call_overflow.
When a call is sent to an overflow number that is a Zendesk number, a regular
ticket with no tag is created.
If recording is enabled for that number, any tickets created include a recording
of the overflow call.
Overflow calls are charged as normal calls, including recordings, when
enabled.
When a call is sent to an overflow number, the caller ID sent to the overflow
number will be that of the original caller.

When voicemail is turned off, no overflow number is configured, and no agents are
available to take a call, your configured voicemail-off greeting plays, and then the
call is disconnected.
If you want to always send calls to the overflow number when they cannot be answered,
see Adding an overflow number.
If you want to send calls to the overflow number depending on the business hours you
have configured, see Adding an overflow number when business hours are
configured.

Tip: If voicemail is turned on, you cannot enable the Overflow calls
option.


Adding an overflow number (for phone lines)
If you don't have business hours configured, follow these steps to add an overflow
number to Zendesk lines that are phone lines (not digital or SIP-IN lines).
To add an overflow number (for phone lines)

In Admin Center, click
Channels in the sidebar, then select Talk and email > Talk.
On the Lines tab, open a phone line for editing.
On the Routing tab (of the phone line), make sure that the
Schedule drop-down list is set to Always route calls.
On the Overflow tab, turn on the Overflow calls toggle, and then
enter a valid phone number that calls will overflow to.

When you are finished, click Save changes. Now, when calls are not
answered by an agent, and voicemail is off, calls will be diverted to the
overflow number you entered.




Adding an overflow number (for digital and SIP-IN lines)
If you don't have business hours configured, follow these steps to add an overflow
To add an overflow number (for digital or SIP-IN lines)

In Admin Center, click
Channels in the sidebar, then select Talk and email > Talk.
On the Lines tab. open a digital or SIP-IN line for editing.
On the Settings tab of the line), make sure that the Enable overflow and agent forwarding for this
line check box is selected and that, in the drop-down list, an

outbound number is selected.
Note: When working with a digital or SIP-IN line,
the Overflow tab only displays when this check box is selected.




On the Routing tab, make sure that the Schedule drop-down list is
set to Always route calls.
On the Overflow tab, select the Overflow calls check box, and then
enter a valid phone number that calls will overflow to.

When you are finished, click Save changes. Now, when calls are not
answered by an agent, and voicemail is off, calls will be diverted to the
overflow number you entered.




Adding an overflow number when business hours are configured (for phone lines)
If you have business hours configured, follow these steps to add an overflow number
to Zendesk lines that are phone lines (not digital or SIP-IN lines).
To add an overflow number when business-hours are configured (for phone
lines)

In Admin Center, click
Channels in the sidebar, then select Talk and email > Talk.
On the Lines tab, open a phone line for editing.
On the Routing tab (of the phone line), make sure that the
Schedule drop-down list is set to Business Hours.
On the Overflow tab, specify overflow options for calls received to your
phone line during certain business hours (specified on the Routing tab).
For example:

In the Inside schedule section, turn on the Overflow calls
toggle, and then enter a phone number that calls will outflow to when
placed inside of your scheduled business hours.
In the Outside schedule section, turn on the Overflow
calls toggle, and then enter a phone number that calls will
overflow to when placed outside of your scheduled business hours.



When you are finished, click Save changes. Now, when calls are not
answered by an agent, and voicemail is off, calls will be diverted to the
overflow numbers you entered, according to the schedule options you
configured.




Adding an overflow number when business hours are configured (for digital or SIP-IN lines)
If you have business hours configured, follow these steps to add an overflow number
to digital or SIP-IN lines (not phone lines).
To add an overflow number when business-hours are configured (for digital or
SIP-IN lines)

In Admin Center, click
Channels in the sidebar, then select Talk and email > Talk.
On the Lines tab, open a digital or SIP-IN line for editing.
On the Settings tab of the line), make sure that the Enable overflow and agent forwarding for this

line check box is selected and that, in the drop-down list, an
outbound number is selected.
Note: When working with a digital or SIP-IN line,
the Overflow tab only displays when this check box is selected.



On the Routing tab, make sure that the Schedule drop-down list is
set to Business Hours.
On the Overflow tab, specify overflow options for calls received to your
digital or SIP-IN line during certain business hours (specified on the
Routing tab). For example:

In the Inside schedule section, select the Overflow calls
check box, and then enter a phone number that calls will outflow to when
placed inside of your scheduled business hours.
In the Outside schedule section, select the Overflow calls
check box, and then enter a phone number that calls will overflow to
when placed outside of your scheduled business hours.



When you are finished, click Save changes. Now, when calls are not
answered by an agent, and voicemail is off, calls will be diverted to the
overflow numbers you entered, according to the schedule options you
configured.




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