Definition of Customer Service: A Glossary of Over 60 Words and Phrases to Simplify Support

Answering, “What is customer service?” is just the tip of the clarity-giving power a shared language creates for your business’ support.

How you define customer service can make or break support. And that’s just the tip of the clarity-giving power a shared language creates.

Customer support, like any other part of your business, has its own lingo, language, and linguistics. Not just technical terms you need to understand for the sake of your backend processes but also frontend, customer-facing phases as well as acronymns, acronyms, acronmyns.

Putting together a glossary for your company and adding it to your support handbook is the first step to clear communication. When everyone both within and outside your team speaks the same language, things go so much smoother.

Of course, it starts with…

What is customer service?

Customer service is a broad term used to define how a company supports its customers before, during, and after a purchase. In other words, customer service isn’t just about customers.

Instead, the idea reaches out to every experience a visitor, lead, prospect, or customer has with your business.

We’ve written extensively about what makes good customer service and the skills necessary to improve support. Both of those articles are worth checking out.

But what really matters is defining all the terms for yourself.

Customer support glossary

To help you shortcut that process, here are 60 customer service terms every agent, leader, and founder needs to know…


A member of the support team who is predominantly responsible for solving support tickets and dealing with customer communications in general.

Application Program Interface (API)

A predefined set of functions and processes that provide the building blocks for creation and/or personalization of applications.

Average First Response Time

The average time it takes for your support team to make first contact with a customer after receiving a request.

Average Handle Time

The average time it takes your support team to resolve a case completely.

Average Reply Time

The average time it takes your support team to get back to a customer (to any communication, not just the first contact).


The amount of unresolved customer support requests in a particular time frame.


A comparison of an agent or company’s performance versus the performance of other agents, companies, competitors, or widely agreed on indicators.


Everything your customers or the general public thinks or knows when they hear your company name.


An issue with your product or service that requires the help of your engineering team to resolve.

Business Hours

The days and hours when your customers can directly reach your support team.

Canned Response (or, Macros)

Reusable replies to common questions, available for all agents to use—they can usually be inserted with a shortcut or click for saving time.


All the possible ways your customers can reach your support team, for example phone, email, social media, live chat, etc.


The loss of clients or customers over a certain period of time.

Customer Effort

The amount of work your customer has to do themselves to resolve an issue. Generally best kept at a low as possible level.

Customer Experience

The customer’s opinion of their experience and relationship with your company through various points of their lifecycle.

Customer Satisfaction (CSAT)

A metric that measures your customers’ general happiness and loyalty with regards to your company.

Customer Service

The assistance, advice and information provided by a company to people, businesses etc that use their product or service.


The practice of selling an additional product or service to an already existing customer.


The time during which your product or service is unavailable for use because of an issue or maintenance.


The ability to understand another person’s feelings—arguably the most important skill of any customer support agent.


A specific characteristic of your product or service that satisfies a certain requirement or need for a customer.


A customer’s opinion of their experience with your company and how you could improve.

Feedback Loop

A process that entails gathering customer feedback, take necessary action, and communicate the results back to the customer(s).

First Contact Resolution Rate (FCRR)

A customer-service metric that measures how often your support team resolves cases in a single response.

Frequently Asked Question (FAQ)

A publicly available collection of the most common questions about your product/service/company, and the answers to them.


The application of gaming aspects⁠—such as leaderboards, point systems, unlocking achievement, levels, etc⁠—to encourage or guide certain customer behaviors.

Help Desk

A software (or platform) companies use to manage their customer support.

In-app Support

A way to contact customer support directly in your web or mobile application without having to exit it.

Key Performance Indicator (KPI)

A data-driven goal that helps measure the performance and objectives of an agent or team.

Knowledge Base

A self-serve online library of everything there is to know about your product or service.

Lifetime Value (LTV)

A prediction or measurement of the profit that can be attributed to a customer during their entire lifecycle.

Live Chat

A support channel that allows you to have real-time conversations with your customers.


The choice of using the product or service provided by a certain company or business over competitors.


A quantifiable measure that is used to track and assess the status and results of a process or activity.

Multi-Channel Support

The ability to provide support in more than just one channel.

Net Promoter Score (NPS)

A measure of how likely your customers are to recommend your product or service to other people.


The process that your customers go through when immediately after the purchase or being a trial.

Open Ticket

The first, default state of a customer support ticket, before being assigned to an agent or dealt with in any way.


Including a third party to provide support to your customers on your behalf.

Overdue Ticket

A ticket that has not been resolved during the agreed time according to the Service Level Agreement.

Pending Ticket

The second stage of a customer support ticket—basically a further research/issue resolving stage before getting back to a customer and closing the ticket.


Tailoring support to individual customers by attaching names, faces, and a generally “human” touch to your communication.


An act of taking steps to help control a (negative) situation before it even becomes an issue.


When a ticket that has been assigned to a certain agent, gets handed over to a different one.

Resolution Rate

The percentage of issues your customer support agents actually resolve from the number of total tickets received.


The ability of a company or business to keep its customers over a specified period of time.


A customer’s publicized opinion about your service, product or company.

Service Culture

A collection of shared values, beliefs, and rules of behavior in a company regarding customer support.

Service Level Agreement (SLA)

A contract between a company and the end-user of their product or service that defines the level of service—often uptime or response time.


A questionnaire sent to the customer—generally after resolving the issue—to find out how happy they were with the support they received.


Each individual issue or request raised by a customer that needs a reply or resolution. (We actually hate the word “ticket” and instead use the term “conversation.”)

Ticket Status

Every stage of a support ticket during its lifecycle—for example, open, pending, closed, etc.


The external expression that conveys your current emotion or attitude, and depends on the situation.


The process of trying to get to the root cause of an issue in order to resolve it.

Unassigned Ticket

A support ticket that has not yet been handed over to a specific support agent.


The act of persuading a customer to upgrade or add on to their already existing product or service.

User Error

An issue that was brought on or caused by the customer as opposed to a faulty product or service.


The steady “personality” of an agent or company that doesn’t change based on the current situation.


An application or part of an interface that enables a user to perform a function.

Make sure you grab the downloadable document with the whole glossary here, and add your own company⁠—or business specific terms to it.

What are some words or phrases that you use that you would add to this list? Let us know in the comments!

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