A plain-English call center glossary: the BPO, staffing, metrics, routing and compliance terms buyers meet when they outsource customer contact, defined.
Why a call center glossary helps buyers
Outsourcing customer contact comes with its own vocabulary, and much of it is used loosely. Two providers can quote the same service level and mean different things; a proposal can promise "dedicated agents" and staff them as a shared pool. This call center glossary defines the terms buyers meet most often when they compare BPO and call center companies, write an RFP or read a monthly report. Where Global Empire Corporation has a fuller guide on a term, the definition links to it.
Outsourcing and operating models
BPO (business process outsourcing)
Contracting a business function — customer service, sales, technical support, back office — to an outside provider that runs it to agreed standards. A call center is one kind of BPO; BPO also covers work that never involves a phone. See what is BPO and BPO vs call center.
Call center and contact center
A call center handles voice calls; a contact center handles voice plus chat, email, text and social channels. The terms are often used interchangeably, but a buyer should confirm which channels a provider actually staffs. See what is a call center.
Inbound and outbound
Inbound work answers contacts customers start — support, orders, enquiries. Outbound work starts the contact — sales, appointment setting, renewals, collections. They need different skills, scripts and compliance rules. See inbound vs outbound.
Onshore, nearshore and offshore
Where the work is delivered from relative to your customers: the same country, a nearby country in a similar time zone, or a more distant one. Each trades off language, culture, hours and cost differently. See onshore vs nearshore vs offshore.
Dedicated and shared agents
Dedicated agents work only on your program; shared agents split their time across several clients. Shared models suit low or irregular volume, dedicated ones suit complex products and steady volume. See dedicated vs shared agents.
Staffing and workforce management
Workforce management (WFM)
The discipline of forecasting contact volume, scheduling agents to meet it and managing the day as it happens. See call center workforce management.
Forecasting
Predicting how many contacts will arrive, by channel and by interval, from history, seasonality and known events. Every staffing decision rests on it. See call center forecasting.
FTE (full-time equivalent)
A unit of staffing equal to one full-time agent's paid hours. Proposals often quote FTEs; buyers should ask how many are on the phones at a given hour, which is a different number.
Shrinkage
The share of paid agent time not available for handling contacts — breaks, training, meetings, coaching, absence. Ignoring it is the most common reason a schedule that looks right on paper leaves the queue short. Try the shrinkage calculator.
Occupancy
The share of an agent's logged-in time spent actually handling contacts rather than waiting for one. Too low wastes capacity; too high burns agents out. See call center occupancy.
Schedule adherence
How closely agents follow the schedule they were given — logged in and available when planned. See schedule adherence.
Attrition
The rate at which agents leave a program. High attrition drains product knowledge and keeps the floor permanently in training. See call center agent attrition.
Performance metrics
Service level
The share of contacts answered within a target time, usually written as a pair such as a percentage within a number of seconds. Always ask how abandoned calls are counted, because definitions differ. See call center service level agreement.
SLA (service level agreement)
The contractual commitment on measures such as service level, response time, quality and accuracy, with what happens if they are missed.
AHT (average handle time)
The average length of a contact from answer to the end of after-call work: talk, hold and wrap-up. Driving it down too hard pushes problems into repeat calls. See average handle time.
FCR (first contact resolution)
The share of issues resolved on the first contact, with no need for the customer to come back. See first call resolution.
Abandonment rate
The share of callers who hang up before reaching an agent. See reducing call abandonment.
First response time
For written channels, how long a customer waits for the first human reply. See first response time.
CSAT, NPS and CES
Customer satisfaction with an interaction, likelihood to recommend the company, and how easy the customer found it to get help. They measure different things and are not interchangeable. See NPS vs CSAT vs CES and customer service metrics.
KPI (key performance indicator)
Any measure a program is managed against. Good KPI sets balance speed, quality and outcome so that no single number can be gamed. See call center KPIs.
Routing and technology
ACD (automatic call distributor)
The system that queues incoming calls and distributes them to available agents according to rules. See dialer and ACD administration.
IVR (interactive voice response)
The automated menu callers hear before reaching an agent, used to identify the caller, route the call or resolve simple requests. See IVR best practices.
Skills-based routing
Sending each contact to an agent with the skill it needs — a language, a product, a level of authority — rather than to whoever is free. See call routing and skills-based routing.
Warm and cold transfer
A warm transfer introduces the caller and the issue to the next agent before handing over; a cold transfer simply moves the call. See warm vs cold transfer.
CCaaS (contact center as a service)
Cloud-hosted contact center software — routing, IVR, recording, reporting — bought as a subscription rather than installed on site. See cloud contact center solutions.
Omnichannel
Service in which voice, chat, email, text and social share one customer history, so a customer can switch channels without starting again. See the omnichannel customer service guide.
Quality, compliance and security
Quality assurance (QA) and calibration
Reviewing a sample of contacts against a scorecard, and calibration sessions in which reviewers score the same contacts to make sure they apply the standard the same way. See the QA scorecard guide.
PCI DSS
The payment card industry data security standard, which governs how card details are taken, stored and recorded. Any program that takes payments by phone has to meet it. See PCI compliance for call centers.
HIPAA
The US law protecting health information, which applies to contact work for healthcare providers, payers and their partners. See HIPAA-compliant answering service.
TCPA and DNC
The US rules on consent for outbound calls and texts, and the do-not-call registries that outbound programs must respect.
Call recording compliance
The consent, disclosure, storage and access rules that apply when calls are recorded, which vary by jurisdiction. See call recording compliance.
Customer experience terms
VoC (voice of the customer)
Collecting and analysing what customers say — in surveys, calls and messages — to improve products and service. See voice of the customer.
Putting the vocabulary to work
The value of a shared vocabulary is in the definitions behind it. When you compare BPO and call center companies, ask each provider to define the measures it proposes — how service level counts abandoned calls, what counts as resolved, how shrinkage is planned — and to report against those definitions every month. Our call center RFP guide shows how to put these questions to providers, and our call center outsourcing page describes how Global Empire Corporation scopes, staffs and reports on a program.
Frequently asked questions
What is the difference between a call center and a BPO?
A call center is an operation that handles customer phone calls, and increasingly other channels. BPO, business process outsourcing, is the wider practice of contracting any business function to an outside provider — customer service and sales, but also back-office work such as data entry, claims and order processing. Every outsourced call center is a form of BPO; not every BPO engagement involves a call center.
Which call center metrics matter most?
It depends on the program, but most buyers start with service level and abandonment for accessibility, first contact resolution for effectiveness, and a customer measure such as CSAT for experience, with average handle time watched rather than driven. The important thing is that every metric is defined in writing so you and the provider mean the same thing by it.
What does AHT stand for in a call center?
Average handle time: the average length of a contact from answer to the end of after-call work. It drives staffing and forecasting, but is a poor target on its own because cutting it too hard creates repeat contacts.
What is shrinkage in a call center?
The share of paid agent time not available for handling contacts — breaks, training, meetings, coaching and absence. Workforce plans add it on top of the agents needed to meet service level; otherwise the floor is short every interval.
