Call Center Staffing: Overstaffed vs. Understaffed (Lean Team Guide)

Staffing a call center is a delicate balance. Too many agents, and you’re burning payroll on idle time. Too few, and customer wait times skyrocket—hurting satisfaction and agent morale. For lean teams especially, every headcount decision has an outsized impact.

Signs You’re Overstaffed

Overstaffing often feels like a “good problem” to have. until you look at the bottom line. Here’s how to spot it:

Low Occupancy Rates – Agents spend more time idle than on calls. If occupancy consistently falls under 70%, you may be paying for more staff than needed.
High Payroll with Flat Volume – Labor costs grow but call volume hasn’t. This is a red flag of excess staffing.
Agents Chasing Work – When supervisors struggle to keep agents busy, your team is oversized.

Why it matters: Overstaffing isn’t just wasted money, it can lower engagement. Agents who are underutilized often feel undervalued.

Signs You’re Understaffed

Understaffing is more common, and more dangerous. Here’s what to look for:

Rising Abandon Rates – If customers hang up before reaching an agent, demand is outpacing your staffing.
High Occupancy Rates – When occupancy sits above 90% for long stretches, your team is stretched too thin.
Long Wait Times – Average speed of answer (ASA) increases, and service levels drop below target.
Burnout & Attrition – Constant pressure leads to stressed agents and high turnover, which only worsens staffing gaps.

Why it matters: Understaffing directly impacts customer experience and employee retention - both expensive to fix.

The Lean Team Balance

For small and mid-sized contact centers, perfect balance is critical. Lean teams don’t have the luxury of absorbing mistakes with excess headcount.

Here’s how to find the sweet spot:

Set a Target Occupancy Range – Most teams thrive between 75–85%. This ensures efficiency without burning agents out.
Use Service Level as a Guardrail – If you target 80/20 (80% of calls answered in 20 seconds), track daily performance and adjust staffing accordingly.
Plan for Shrinkage – Time off, training, and breaks often eat 25–35% of schedules. Ignoring shrinkage is one of the fastest ways to appear “short-staffed.”
Run Forecasts – Use historical call volume and handle time to predict staffing needs. Tools like Spark Queue can take the guesswork out.

Quick Checklist: Are You Balanced?

Is occupancy between 75–85%?
Are service levels consistently met?
Do agents report being busy but not overwhelmed?
Is attrition steady and manageable?

If you answered “yes” to most of these, you’re in the staffing sweet spot.

Answered with “No” or “IDK”?

If you weren’t confident in most of the checklist questions, you’re likely overstaffed or understaffed—and it’s costing your team.

Here’s what to do next:

Forecast smarter – Use historical call data and realistic shrinkage assumptions.
Validate occupancy and service level – Don’t guess.
Build lean schedules that flex with volume – This is where Spark Queue shines.

👉 Spark Queue helps lean teams like yours forecast accurately, balance staffing, and build schedules—without the headaches.