Skip to Content

Requestor or Requester: What to Call Someone Making a Request

When the subject of a sentence performs an action that characterizes them, we can add either the -er or -or suffix to the verb. But how do we know which of these two suffixes to use, particularly when we want to reference the person making a request? In other words, what is the difference between a “requestor” and a “requester”?

“Requester,” is the far more common form to refer to a person making a request. Still, some dictionaries list the less common “requestor” for this application. Further, “requestor” is far more common in the world of technology, where one piece of technology requests something from another. This makes both forms of the term acceptable depending on the context and application.

Read on to learn more about the use of “requester” and “requestor,” the guidelines for adding suffixes to for nouns of agency, and the niche technical application of “requestor.”

Suffixes and Nouns of Agency

Of course, the standout difference between these two words is that there is a minor difference in how we might spell them. They share the base word “request,” which is why they both have the same meaning, at least according to British English sources like Lexico (source). 

It’s the suffix that we use at the end of each word that’s different; namely, we use -er for one and -or for the other. However, it’s important to note that The Merriam-Webster Dictionary does not yet recognize the alternative spelling “requestor.”

Many often confuse these suffixes since they share similar pronunciations and perform the same function grammatically — they both denote nouns of agency or agent nouns.

An agent noun is a specific term grammarians use to speak about the source or originator of an action in a sentence. We can form such a noun by taking the verb, or doing word, and modifying it using a noun suffix to function as the subject or an object in a sentence.

Consider the following examples where we modify the base word with the noun suffix -er.

  • Play → player
  • Sing → singer

We can take practically any verb and modify it to indicate someone or something that performs the action as an occupation or a person or thing generally associated with that action.

The Difference Between Requester and Requestor

In this case, the base word for both versions is “request,” which, as a verb, simply means to ask for something in a way that is both official and formal yet implies courteousness. 

Most of the time, both function identically. The key difference between “requester” and “requestor” isn’t so much the meaning of the words but, rather, who or what they more often describe.

When we consult the Corpus of Contemporary American English, we see that legal practitioners use both “requester” and “requestor,” though “requester’” is still more common. However, “requestor” appears in technology patents and documents from research and development departments at companies like IBM (source).

The Meaning of Requester

For example, what do you call a person who makes a request? You will more often see the use of “requester,” but someone might instead use “requestor” less frequently for this application.

The Collins English Dictionary lists “requestor” as chiefly British English (source), and the Cambridge Dictionary lists “requestor” as an alternative spelling of the word (source).

The Merriam-Webster Dictionary defines a “requester” as one who makes a request or asks something of another (source). Most often, the requester is after some form of an official document.

As a result, people most often use “requester” to describe an interaction between two people.

The Meaning of Requestor

In contrast to “requester,” you’re more likely to see someone use “requestor” to refer to an inanimate object such as a computer when it requests information from another computer on the same network.

Computer scientists use it to describe one of several ways that computers in a network communicate with one another (source).

It’s also not uncommon for persons in the technology field to adopt a different spelling for a particular application for a word. For example, such is the case for the British English use of “programing,” as we covered in another of our articles, entitled “Programming or Programing: Which Is Correct?

Using Requestor With Technology

Interconnected systems are common in the world of development and software. For example, when we link computers together to form a network, they can share information within that network.

This interconnectivity is particularly noticeable when we look at internet security and software that authenticates users as they navigate websites, applications, and other sources of information.

Often, multiple technology companies collaborate to develop these to ensure that their users are safe when they use their software. A notable identity protocol involving requestors is WS-Federation (source).

Software developers design these systems for convenience. Without these systems, you’d need to re-authenticate every time you accessed a new page on your company’s intrasite or opened a sensitive document.

Instead, some technology companies have developed a Single Sign-On solution (or SSO for short) that only requires one sign-in from a user perspective, and then the protocols take over from there.

These can be either passive authentication, redirecting users to authenticate themselves through HTTP redirects, or active authentications that use a messaging protocol called SOAP.

While these descriptions and explanations are all rather technical, they are all based on the simple fact that one piece of hardware or technology that is in a network with another can request information from and send information to that piece of technology.

In the field of computer technology, you are more likely to see the spelling “requestor” for this application because one piece of technology makes a request based on information that another piece holds.

In the vast majority of these cases, we see companies like Microsoft and IBM using “requestor” with the -or suffix instead of “requester” with the -er suffix.

Examples of Requesters

In contrast, there are several different circumstances where people request things from other people. This section will cover some of the most common examples.

When Requesting Your Presence or Time

A modern example, which we’ve grown ever more used to recently, is receiving a meeting request. While these requests come through as a notification or an email in current practice, their history goes back to cordial invitations stating “Your presence is requested” at an event.

In cases like this, they would refer to the meeting organizer as the “requester” since they initiated the contact and are finding out — or requesting to know —  whether you’d be available to meet at that time.

A Petitioner Requesting Action

Noah Webster’s dictionary described a requester as the same as a petitioner (source). For example, in legal terms, a creditor might issue a request for payment of a debt (source).

The petitioner is usually someone who wants a court or legislative body to decide on their case. During proceedings, one party would be the petitioner or plaintiff, and the other would be the respondent or defendant.

Requesting Official Documents

A requester is more often an individual requesting official documents from a government entity. For example, someone might request a patent from the US Patent and Trademark Office (source).

Similarly, someone might request forms from the Internal Revenue Service (IRS) (source) or information from the Department of the Interior through a Freedom of Information Act (FOIA) request (source).

While you are more likely to see “requester” in this context from Cornell Law School or Harvard Law School, you might still see the term “requestor” on occasion (source).

A Radio’s Request Line

As technology grew and provided radio stations with a way to hear from their listeners, it didn’t take long for them to implement a request line. Naturally, listeners supported this since it meant they’d be able to listen to their favorite song, as well as have the chance to be on air.

We can consider all people who submit these requests, regardless of whether they’re via telephone, through text, or made through an app or website, as requesters since they’re requesting the station to play a specific song.

Available Upon Request

When you’re applying for a job, it’s not uncommon to keep your resume as brief and uncluttered as possible, which often means not specifically listing your references for past experience.

Recruiters do want to know where you’ve worked before and that they’ll be able to verify this with your previous employers, though. The middle ground, therefore, is simply pointing out that your references are available upon request.

There are also other circumstances where we might apply the same concept, such as an item on a menu that varies in price due to availability or contains seasonal ingredients that are hard to source.

Rather than constantly altering their menu to reflect the accurate pricing, a safer route is to state that the price is available upon request, meaning a patron would ask their waiter for it if they are interested.

In both situations, we could consider the recruiter or the interested patron as a requester since they are the ones asking for the extra information.

Applying -er and -or Suffixes

Image by Suzy Hazelwood via Pexels

When we break “request” down into its component parts, we can see that it ends in a consonant cluster —  referring to the -st at the end of the word. This is important for us to note since it is far more common for us to use the -er suffix on verbs that end in a consonant cluster than it is to use -or.

The -er Suffix

It’s very common to turn nouns ending in consonant clusters into agent nouns ending in -er. These include words ending in clusters such as -pt, -st, -sk, nd, -ld, -lf, -lp, -mp, etc.

  • Adapt → adapter
  • Request → requester
  • Respond → responder
  • Weld → welder

The -or Suffix

When we do use the -or suffix instead, it is usually for verbs that end with -ate, -ct, or -it. Consider the following example in the table below showing how we transform these words into agent nouns.

  • Calculate- → Calculator
  • Contract → contractor
  • Create → creator
  • Visit → visitor

But, as the saying goes, there is bound to be an exception for every grammatical rule. “Request” does not end in either -ate, -ct, or -it, which makes attaching the “-or” suffix to it all the more unusual.

Still, there are a few other exceptions to this rule, such as “inventor” and “investor,” so “requestor” is simply one more possible exception.

  • Invent → inventor
  • Invest → investor
  • Request → requestor

However, since this practice does not fit the general rule, it’s easy to understand why word processors and spell checkers often flag the word “requestor” as incorrect and identify it as a misspelling of “requester.”

The Merriam Webster Dictionary does not recognize it, and those dictionaries that do, like the Cambridge Dictionary, always list “requester” ahead of “requestor.” As a general rule, it’s usually best to go with the first spelling option listed in the dictionary.

Agent Nouns Ending in -ar

Even rarer than the -or suffix for agent nouns is the -ar suffix. Two instances where we would use an -ar ending after a consonant cluster would include “bursar” and “registrar.” The former means a treasurer or one who controls the purse, Latin “bursa,” while the latter is someone who registers.

This article was written for

However, in both cases, we actually derive the agent noun from a noun instead of from a verb.

Final Thoughts

“Requestor” and “requester” both share the same base word and generally mean the same thing. However, software engineers and computer specialists have increasingly adopted the less common variant “requestor” for a specific application.

Unless you’re referring to some sort of request-response process between computers on a network, “requester” is the spelling you’re looking for. It is by far the most common spelling, and it follows the general spelling rules for consonant clusters like -st.