The Hidden Cost of Under- and Overstaffed Contact Centres

Are you stuck in a doom loop of managing an under- or overstaffed contact centre but don’t know how to break the cycle? It’s a common problem that many struggle to escape from.

That’s why we asked contact centre consultant Dara Kiernan to explain what’s really going on under the bonnet, the hidden costs of getting it wrong, and how you can turn the situation around.

Overstaffing Is Like Having a Fridge Full of Milk “Just in Case…”

Overstaffing is like having a fridge full of milk “just in case…” and then realizing half of it has gone off.

Back in the 80s and 90s, my parents bought milk in huge quantities because, as my mother used to say, “We might run out!”

Even though there were only a few of us in the house, every supermarket trip ended the same way: “Do we have milk at home? Not sure. Let’s get some anyway. Just to be safe… You can never have too much.”

Spoiler alert – we always had milk at home! I can still remember that sour smell when you opened the fridge door – money literally curdling in front of you.

It Feels Safe to Have Extra People Waiting Around, but It’s a Costly Leak

That’s what overstaffing feels like in a contact centre. You’ve stocked up for a rush that never comes, and now you’re stuck with hours you can’t pour back into the bottle.

It feels safe to have extra people waiting around, but it’s actually one of the quietest and costliest leaks in a contact centre budget – like throwing money in the freezer and hoping it magically multiplies overnight.

3 Ways to Avoid Overstaffing

Here are a few ways to keep your staffing levels healthy – without ending up with a fridge full of frozen wages:

1. Forecast in Layers

Think of your staffing like an onion.

Core layer – Your minimum number of agents needed to handle regular demand.
Flexible outer layer – A mix of part-time staff, temp workers, or on-call resources you can add when demand spikes.

This gives you a stable base without overcommitting to fixed costs. It’s like knowing where to buy your milk if needed, but not buying six “just in case”.

For the underlying principles of great agent scheduling, read our article: The Dos and Don’ts of Agent Scheduling

2. Use Historical Data – But Add a Pinch of Common Sense

Historical call data is powerful, but it isn’t perfect.

Look beyond the numbers and factor in real-world context – things like promotions, seasonal spikes, public holidays, and even the weather.

A sunny bank holiday weekend might tank call volumes.
A surprise storm could double them.

Data alone is like a map without street names: useful, but easy to misread. Blend analytics with local knowledge to get a forecast that actually reflects what’s happening on the ground.

3. Cross-Train for Agility

Another approach is to equip your current team to be more versatile – instead of hiring extra people “just in case”.

After all, when agents are trained to handle multiple types of queries – or even tasks from other departments – you get a team that can pivot instantly!

If call volumes dip, they can switch to emails, live chat, or back-office work instead of sitting idle. It’s like encouraging everyone in the house to drink tea, coffee, or hot chocolate – no matter what’s in the fridge, nothing goes to waste.

This approach doesn’t just protect you from overstaffing costs. It creates what I like to call “multilingual staff”. And by multilingual, I don’t mean languages like French or Spanish. I mean people who are fluent in different parts of your business.

When someone understands multiple processes and perspectives:

They think bigger because they see how everything connects.
They collaborate better with other teams, breaking down silos.
They communicate more clearly because they understand the “dialects” of different departments.

In other words, cross-training doesn’t just make your operation leaner – it makes it smarter, more connected, and ready to handle whatever chaos tomorrow brings.

And here’s the best part: by cross-training, you’re not just improving operations – you’re investing in your people, helping you retain great talent while building a stronger, more resilient business.

Not sure if multi-skilling is for you and want to know the pros and cons, read our article: Multi-Skilling Agents – Is It Really Best?

★★★★★

Firefighting an Understaffed Shift Is a Total Nightmare

If overstaffing is like having a fridge full of milk that goes sour, understaffing is the opposite.
It’s like opening the fridge first thing in the morning to find one slice of cheese and half a jar of pickles. You’ve got a family to feed, but you’re starting the day with almost nothing.

That’s what it felt like walking into certain shifts in the contact centre.

Before I’d even sat down:

Wallboards flashing red
Queues spiralling
A sinking feeling in my stomach – like turning up late to a party where everyone’s already angry at you

The visible chaos was bad enough, but the hidden impact was even worse:

Burnout and turnover as great people left under relentless pressure
Slipping quality, because when you rush, accuracy suffers
Reputation damage, with angry reviews lingering long after the root problem is fixed

It was like putting out one fire, only to turn around and see three more blazing behind you.

3 Ways to Fight Back Against Understaffing

Back then, we didn’t have perfect forecasting tools or AI-driven scheduling systems.
What we had were lessons learned the hard way, a lot of trial and error, and some good old-fashioned creativity.

Of course, some of the same principles that help avoid overstaffing – like accurate forecasting and having flexible resources – also play a role here.

But when you’re staring down a wallboard flashing red and a queue that looks like it’s stretching into next week, you need more than just scheduling tweaks.

Here’s what really helped me fight back against understaffing in the moment:

1. Redesign Self-Service With Real Customer Journeys in Mind

At one point, I realized a huge chunk of our calls never needed a human in the first place.
The problem was our self-service options were so bad that customers would hang up halfway through the IVR or skip the FAQs entirely and just hammered zero to speak to someone.

When we finally redesigned our self-service with real customer journeys in mind, it was like night and day:

The simple, repetitive issues started solving themselves.
Agents could focus on the complex, valuable conversations.
Queues became manageable, even during busy periods.

Just remember, the goal isn’t to replace people – it’s to remove the noise!

For advice on how to elevate your self-service channels for everyone’s benefit, read our article: 7 Ways to Elevate Your Self-Service Options

2. Shift Focus From Speed to First Call Resolution (FCR)

When you remove the quick, easy calls, Average Handling Time (AHT) will go up.
And that’s okay!

You can’t remove all the “quick wins” and then expect AHT to magically stay the same.
What’s left are the longer, more complex calls – and that’s exactly where you want your skilled agents to spend their time.

So, shift focus:

From speed to first-call resolution (FCR) and customer satisfaction (CSAT).
Don’t punish agents for doing deeper work just because it takes longer.

Otherwise, you end up like a football manager yelling at the goalie to score goals – completely missing the point of their role.

By recognizing this shift upfront, you prevent a lot of frustration later – both for your agents, who feel unfairly judged, and for leadership, who might misinterpret the numbers as a problem when, in reality, it’s progress.

For more on shifting focus away from speed to FCR, read our article: Why You Should Embrace the Complexity of Longer Talk Time

3. Spread the Load With Callback Systems

One of the best changes we made was introducing callback functionality.

Instead of customers sitting on hold for 30 minutes (getting angrier by the second), they could:

Request a callback.
Hang up.
Get on with their day while we held their place in the queue.

Not only did this smooth out the call-flow, but it also:

Reduced the emotional temperature of interactions.
Took pressure off the team.
Improved customer satisfaction dramatically.

It’s a small change that made a big difference, especially when we were struggling to keep up!

But here’s where many organizations get it wrong: A callback shouldn’t just suit your operation – it has to work for the customer’s life.

Most people call when it suits them. Maybe it’s their lunch break, or the five minutes between meetings, or while they’re standing in line at the supermarket.

If you call them back half an hour later, they might already be:

Back in a meeting
Picking up the kids
Driving
Or somewhere they simply can’t answer the phone

It’s like turning up at someone’s house unannounced, ringing the doorbell, and then getting annoyed that they weren’t waiting at the door for you.

To avoid frustrating your customers even more, offer them a choice:

Immediate callback – The very next available agent calls them, keeping them near the front of the queue.
Scheduled callback – The customer chooses a specific time slot that works for them.

That second option is a game-changer because it puts the customer in control, and control creates confidence.

Think of it like booking a delivery slot with the supermarket – you don’t just want to know that your groceries are coming “sometime today”. You want to know when so you can plan around it.

By letting customers choose, you:

Reduce missed calls and endless voicemail ping-pong.
Lower frustration because expectations are clear.
Create a smoother, more predictable workflow for your team.

A callback system isn’t just a queue management tool – it’s a signal of respect.
It tells customers: “Your time matters as much as ours.”

And finally, make sure It works!

Whatever callback system you implement, test it and test it again. Because here’s the thing: nothing destroys trust faster than a promised callback that never comes.

Be honest – how many of us have requested a callback, waited patiently, and… nothing?

It’s infuriating.

If you get callbacks right, you’ll win loyalty.

If you get them wrong, you’ll add yet another angry customer to the queue – and this time, they’ll be even more frustrated than before!

Written by: Dara Kiernan, Leadership Development and Contact Centre Consultant

If you are looking for more information to improve your contact centre scheduling and staffing, read these articles next:

Author: Dara Kiernan

Published On: 2nd Mar 2026
Read more about - Call Centre Management, Call Handling, Capacity Planning, Dara Kiernan, Employee Engagement, Forecasting, Management Strategies, Self Service, Staffing, Team Management, Top Story, Workforce Planning