What is call queuing and how do businesses use it?

Busy phone lines and frustrated customers who hang up mean lost revenue and bad reviews. Call queuing ¹ fixes this without hiring a whole new team.

Call queuing puts incoming callers into a controlled virtual line whenever agents are busy, then uses routing rules, announcements, and callbacks to reduce missed calls and protect service levels.

Call queues sit between your phone numbers and your agents. They decide who waits, who moves forward, where overflow goes, and how you communicate with callers while they hold. In IP and SIP environments, queues are part of the UC or contact center platform, not a separate black box.

How do queues reduce abandoned calls?

High call volume often leads to long waits and high abandonment. Customers hang up, then complain on email or social media, which only creates more work later.

Queues reduce abandoned calls by controlling how callers wait, setting clear limits, offering callbacks and self-service, and routing overflow before people give up in frustration.

What abandonment really means

An abandoned call ² is a customer who entered the queue and hung up before reaching an agent. Some abandonments are harmless. For example, a caller realizes they dialed the wrong number. Many are not harmless. They are customers who ran out of patience.

So the goal is not “zero abandonment.” The goal is “few unhappy abandons” and “no abandonment from critical callers.” Queues give you tools to shape this.

At a basic level, queuing is just “first in, first out.” But business rules turn this simple line into a flexible system:

• Maximum wait time before we auto-redirect
• Maximum number of callers allowed in a queue
• Special treatment for high value or urgent calls
• Overflow to backup queues, IVRs, or voicemail

If you do nothing, the queue becomes an endless hallway with no clear exit. If you design it carefully, the queue becomes a controlled funnel with visible doors.

Queue levers that cut abandonment

There are four big levers you can use, and many contact centers apply them together to reduce call abandonment ³.

1. Expectation setting
   When callers hear estimated wait time or position in queue, the wait feels shorter and fairer. Uncertain waits feel much longer. Simple messages like “about five minutes” work better than silence.

2. Perceived progress
   Updates such as “you are third in line” or “we are connecting you to the next available agent” give a sense of motion. Music and useful tips also help fill “empty” time.

3. Real escape routes
   Offer options: press a key for a callback, leave a voicemail, or jump to self-service in IVR. People feel less trapped, so they are less likely to hang up in anger.

4. Smart overflow
   Use policies to shift calls when conditions get bad. For example, if wait time crosses a threshold, send non-urgent callers to another team, to a different site, or to a message that sets a better expectation.

You can map these levers in a simple table:

In practice, small changes matter. When I help tune queues, we usually start with simple messages, then add callbacks and overflow rules. The result is fewer angry abandons and a more predictable workload for agents.

Which queue strategies should I choose?

It is easy to turn on “a queue” with default settings. The real challenge is matching queue strategy to your business model, skills, and customer mix.

Pick queue strategies based on what you sell, how complex your calls are, and how your agents are organized, then combine FIFO, skill-based routing, and priority queues instead of using only one pattern.

Common queue strategies in simple language

Even in advanced platforms, most real setups use a few basic strategies.

• FIFO (first in, first out)
  The simplest model. The first caller who entered and is still waiting gets the next free agent. Good for fairness.

• Longest idle agent
  The caller goes to the agent who has been free the longest. Useful when you want balanced workload between agents.

• Round robin
  Calls rotate between agents in order. This also balances workload and is good for small sales teams.

• Skill-based routing ⁴
  Calls go to agents who have the right skills: language, product, or tier. The system decides route based on IVR choices, caller data, or number dialed.

• Priority / VIP queues
  Some calls go to the front of the line. For example, platinum customers, emergencies, or internal helpdesk calls from executives.

Most platforms let you combine these. For example, you can use skills first, then FIFO within each skill group, with extra rules for VIPs.

Matching strategies to real scenarios

The right strategy depends on what you are trying to optimize.

In SIP and UC environments, queues often sit behind auto attendants and IVR menus. You can route based on dialed number (for example, sales vs support), IVR choices, or even CRM data from a screen pop.

One simple rule helps: do not use more complexity than your supervisors can explain in a ten-minute whiteboard session. If nobody understands why a caller waited longer than someone else, trust in the system drops.

Can I offer announcements and callbacks?

Silence during hold feels like a system error. Endless music feels like nobody cares. Announcements and callbacks turn waiting time into managed time.

Yes, modern queue platforms let you play custom announcements, share estimated wait times, offer self-service, and give callers a callback option instead of sitting on hold.

Using announcements the smart way

Announcements do more than say “your call is important to us.” When used well, they reduce stress and repeat calls.

A simple structure that works in most queues:

1. Greeting and validation
   Thank the caller and confirm the line is active.

2. Honest wait expectation
   Give an estimated time or a simple bracket such as “under five minutes.”

3. Options and alternatives
   Offer callback, self-service, or a web link for common tasks.

4. Useful short messages
   Share quick tips that really help, not long ads that repeat every 20 seconds.

You can also change announcements by time of day or by event. For example, when a system is down, you can acknowledge it and give the latest status. This avoids dozens of repeated calls on the same issue.

Callbacks and virtual hold

Callbacks take the idea further. Instead of holding the line, the system keeps the caller’s place in queue and calls them back when an agent is free. There are two common modes:

• Agent-reserved callback (true virtual hold) ⁵
  The system dials the customer only when an agent is ready, then connects the two. The caller’s wait moves from “on the phone” to “off the phone,” but the place in line stays the same.

• Customer callback request
  The system stores the caller’s number and later attempts a call when load is lower. This is more flexible but less strict about exact queue position.

A simple comparison:

In my view, callbacks work best when:

• You offer them after a short wait, not after ten minutes of pain
• You confirm the caller’s number and give a rough callback window
• You limit the feature to queues that can honor the promise

Platforms that support SIP and WebRTC can handle callbacks over the same infrastructure as normal calls. Your agents answer a callback like any other inbound call, but the system tags it as “callback” for reporting.

How do I set queue SLA targets?

Many teams copy a random “80/20” rule for service levels. Without context, this number means little, and it may not match your budget or customer expectations.

Set queue SLA targets by linking business goals, customer expectations, and real data on volume and handle time, then use those targets to drive staffing, overflow rules, and callback policies.

Core SLA concepts for queues

Two metrics sit at the center of queue SLAs:

• Service Level (SL) ⁶
  The percentage of answered calls that met a wait time target. For example, 80% of calls answered within 20 seconds.

• Average Speed of Answer (ASA)
  The average time callers waited before an agent answered.

Both are important. SL shows how many customers you served “fast enough.” ASA shows how the average customer feels. You can hit a numeric SLA while still giving some callers a very bad experience if distribution is uneven.

You also track abandon rate, since this reveals how many callers left before being answered. These three metrics sit together.

A simple approach to choosing SLAs

You do not need a PhD in math to set useful targets. A practical method looks like this:

1. Segment your queues
   Emergency, sales, and support queues need different promises. For example, you may target 90/10 for emergency, 80/20 for sales, and 70/60 for general support.

2. Collect baseline data
   For a few weeks, measure current SL, ASA, AHT, and abandon rate per queue. Do not change anything yet.

3. Talk to the business
   Ask owners what “good” looks like. For example, “sales should answer almost every call under 30 seconds” or “support can wait a bit longer if quality stays high.”

4. Run simple staffing models
   Use Erlang C or similar tools ⁷ to see how many agents you need to hit a target with your volume and AHT. Without this, you may promise something you cannot fund.

5. Set realistic targets
   Choose SLAs that match both customer expectations and budget. Document them and align routing, callbacks, and overflow rules to support them.

You can summarize this mapping as:

When you accept card payments over the phone, you also need to consider PCI-DSS. This affects how you record calls, what happens when customers enter card numbers, and how you design flows inside the queue. Many platforms add “pause recording” or secure IVR so card data never enters the recording system.

SLA targets are not forever. Review them at least twice a year. As channels shift from voice to chat, and as self-service improves, you may be able to relax or tighten certain targets. What matters is that your queue design and staffing always align with a clear, shared promise.

Conclusion

Call queuing is more than a waiting line. It is a set of rules and tools that shape how customers wait, who gets served first, and how your team meets realistic service level promises without burning out.

Footnotes