The Difference Between Advisor and Adviser

A career adviser assisting a client at a job fair
Career Adviser Assists Applicant at Job Fair. Win McNamee/Getty Images 

There you are, happily writing your latest masterpiece, when suddenly you need to use the word “adviser,” — or is it “advisor?” you wonder. Which is right? Much like toward and towards, the words advisor and adviser often pose some common conundrums: Do the two different, but correct, spellings of the same word convey subtly different meanings? And, even if both are technically correct, is one more “appropriate” than the other in certain circumstances?

Both advisor and adviser are examples of a category of nouns called agent nouns — nouns that refer to someone or something that performs the action of a verb and typically ending in either “or” or “er,” like “worker” or “detector.” Both advisor and adviser refer to one that advises or gives advice to others. For example, a government official or agency, like the Consumer Product Safety Commission, that offers advice to the public. The word adviser, ending with “er” is of English origin, while advisor is of Latin origin.

So, even though a person who writes is a writer, a person who dances is a dancer, and a person who wanders is a wanderer, a person who advises can be an adviser — or an advisor. Yes, English can be a confusing little language, can’t it?

If their meaning is the same, how do you decide whether to use advisor or adviser? While both spellings are acceptable usages, both are not equally preferred.

Should You Use Adviser or Advisor?

Overall, there appears to be a preference for the use of adviser (with an “er”). According to the Oxford English Corpus, adviser appears in texts collected from around the world about three times for every one occurrence of advisor. As a result, English language usage guides like the Associated Press Stylebook and Garner’s Modern American Usage list adviser as the recommended — but not mandatory — spelling. However, the Virginia Tech University Style Guide recommends the use of advisor as it is “used more commonly in academe” adding, “Adviser is acceptable in releases going to organizations that follow AP style.” Several other university style guides follow suit in recommending advisor over adviser in scholarly texts.

Both forms of the word first appeared in English texts written between 1605 and 1615. However, it is believed that adviser had been commonly used for several years before advisor first appeared, perhaps contributing to its wider range of acceptance today.

While adviser is the heavily preferred spelling outside of North America countries, in the United States and Canada, advisor (with an “or”) is often seen when used as part of official job titles such as “financial advisor” or “academic advisor.” Advisor also appears to be preferred by the U.S. government, as in National Security Advisor and Veterans' Preference Advisor. Once again, however, this is a preference, not a rule, as the use of adviser in titles is often seen. Consider these examples from major U.S. publications:

“President Obama’s national security adviser, Susan E. Rice, urged ...” — New York Times

“The group is a network of independently owned advisors who ...” — Forbes

Advisor is more heavily used, both in titles and otherwise, in scholarly and academic texts throughout the English-speaking world. This may be due to the fact that the “-or” suffix is commonly used with verbs that have a Latin origin. There is a largely unproven theory that due to its Latin origin, advisor denotes a more “formal” tone than adviser, thus making it better suited for use in academic writing.

In addition, some industries, publications, and institutions use their own writing style guides, which call for the use of either adviser or advisor whether it is more commonly used in their home country or not.

One Rule: Adviser as an Adjective

While adviser is the generally preferred spelling when used as a noun, the adjectival form of "adviser" is correctly spelled “advisory.” For example:

As a Noun: “I work as an adviser for my company.”

As an Adjective: “I will be working for the firm in an advisory capacity.”

This may contribute to the confusion surrounding adviser vs. advisor. However, while either adviser or advisor can be used in most cases, "advisory" is the only correct adjectival spelling. “Advisery” isn’t even a word.

So Which One Should You Use? Just Be Consistent

Since neither adviser nor advisor is grammatically wrong, is there a good reason to choose one over the other? While usage of the two words really comes down to a matter of choice, they should be used consistently. With few exceptions, they should not both be used in the same document.

Those few exceptions include usage in proper names and titles, and in quotations. When used in proper names and titles, adviser and advisor should always be spelled as they are in the title. In the president’s “Council on Economic Advisers,” for example, use of advisor would be incorrect. Similarly, when quoting text from another document, adviser and advisor should be spelled as they are in the source.