Professional organizations create many types of public-facing documents, including press releases, newsletters, websites, annual reports, announcements, and community communications. For these materials, consistency and clarity are essential.
That’s why so many organizations use Associated Press (AP) Style.
AP Style provides guidelines for grammar, punctuation, capitalization, numbers, dates, titles, and other writing decisions.
It helps organizations create content that’s clear, concise, and easy for a broad audience to understand.
However, AP Style has tons of specific rules, and even experienced writers can make mistakes. Small inconsistencies can affect the professionalism of your documents and create extra work during the editing process.
Understanding common AP Style mistakes can help your organization produce cleaner, more consistent communications.
Inconsistent Use of the Oxford Comma
One of the most recognizable differences in AP Style is the use of the serial comma, also known as the Oxford comma.
AP Style generally does not use a comma before the final item in a simple list.
AP Style example:
The program serves students, families and educators.
A common mistake is adding the final comma:
The program serves students, families, and educators.
While the Oxford comma is widely used in other style guides, AP Style typically leaves it out unless it’s needed for clarity.
Incorrect Capitalization of Job Titles
AP Style has specific rules for capitalizing professional titles.
Capitalize a title when it appears directly before a person’s name.
Correct:
Director Maria Lopez announced the initiative.
Do not capitalize a title when it appears after a person’s name or when it is used generally.
Correct:
Maria Lopez, director of communications, announced the initiative.
Correct:
The director of communications announced the initiative.
A common mistake is capitalizing every job title throughout a document.
Using Incorrect State Abbreviations
AP Style uses specific abbreviations for states when they appear with a city.
For example:
Correct:
Albany, N.Y.
Incorrect:
Albany, NY
AP Style state abbreviations are different from postal abbreviations used for mailing addresses.
Organizations should be consistent when referencing locations throughout a document.
Incorrect Use of Numbers
Numbers are a common area where writers make AP Style mistakes.
AP Style generally spells out numbers one through nine and uses numerals for numbers 10 and above.
Correct:
The organization provided services to five communities and 15 schools.
However, AP Style includes exceptions for:
- Ages
- Measurements
- Money
- Percentages
- Dates
- Addresses
Because number rules vary depending on context, careful review is important.
Writing Out Percentages Incorrectly
AP Style uses the % symbol with numerals.
Correct:
The program experienced a 25% increase in participation.
A common mistake is spelling out the word “percent,” but the rule changed in 2019.
Incorrect:
The program experienced a 25 percent increase in participation.
Using the correct format helps maintain consistency in professional communications.
Incorrect Use of Months
AP Style abbreviates certain months when they appear with a specific date.
The months abbreviated are:
- Jan.
- Feb.
- Aug.
- Sept.
- Oct.
- Nov.
- Dec.
Correct:
The event will take place Sept. 15, 2026.
When a month stands alone or appears with only a year, AP Style generally spells it out.
Correct:
The event will take place in September 2026.
Misusing “More Than” and “Over”
AP Style traditionally recommends using more than when referring to numbers.
Correct:
More than 500 people attended the event.
A common mistake is using over in this context.
Incorrect:
Over 500 people attended the event.
Although many people use these terms interchangeably, AP Style prefers more than for quantities.
Incorrect Use of “That” and “Which”
AP Style follows traditional grammar rules for these words.
Use that for essential information.
Example:
The programs that serve children received additional funding.
Use which for nonessential information.
Example:
The programs, which serve children across the county, received additional funding.
Understanding this difference helps create clearer sentences.
Related: Frequently Confused Words in Professional Writing
Overusing Abbreviations
Abbreviations can make writing shorter, but too many can make documents harder to understand.
AP Style recommends avoiding unnecessary abbreviations, especially when writing for a general audience.
Consider whether your readers will understand the abbreviation before using it.
For example, spell out an organization’s name before using an abbreviation.
First reference:
The National Association of Community Organizations (NACO)
Later references:
NACO
Incorrect Use of “Affect” and “Effect”
These commonly confused words appear frequently in professional writing.
Affect is usually a verb meaning to influence.
The policy change will affect employees.
Effect is usually a noun meaning a result.
The policy change had a positive effect.
Using the wrong word can change the meaning of a sentence.
Incorrect Capitalization of Seasons
AP Style does not capitalize seasons unless they are part of a formal name.
Correct:
The organization launched its spring fundraising campaign.
Incorrect:
The organization launched its Spring fundraising campaign.
Using “Among” and “Between” Incorrectly
AP Style follows the traditional distinction between these words.
Use between when referring to two people or things.
The agreement was between the organization and the foundation.
Use among when referring to more than two.
The funding was distributed among five community partners.
Incorrect Formatting of Headlines and Titles
AP Style has specific preferences for headlines and titles.
For composition titles, AP Style generally uses quotation marks rather than italics.
Correct:
The organization released “Annual Impact Report.”
A common mistake is using italics or inconsistent formatting across documents.
Confusing “Its” and “It’s”
This common error appears frequently in professional documents.
Its shows possession.
The organization updated its website.
It’s means “it is” or “it has.”
It’s important to review the report before publishing.
Because both words are spelled correctly, automated tools may not catch this mistake.
Why AP Style Consistency Matters
Small style decisions can have a big impact on how professional your documents appear.
Inconsistent AP Style can lead to:
- Confusing formatting
- Additional review time
- Reader distractions
- A less polished final product
Following AP Style helps organizations create communication that feels clear, credible, and consistent.
Related: AP Style vs. Chicago Style
How Professional Editing Helps
AP Style includes hundreds of rules, and applying them consistently can be challenging, especially when multiple contributors are involved.
Professional editors help ensure that your documents follow AP Style while maintaining your organization’s voice and goals.
An editor can review:
- Grammar
- Punctuation
- Numbers
- Dates
- Capitalization
- Titles
- Abbreviations
- Overall consistency
Professional editing helps organizations avoid small mistakes that can distract from their message.
At SP Editing, we help nonprofits, government agencies, educational institutions, healthcare organizations, foundations, and businesses create polished, professional documents that follow appropriate editorial standards.
Our editing services support:
- Annual reports
- Grant proposals
- Newsletters
- Websites
- Public communications
- Policy documents
- Organizational publications
We help organizations improve clarity, consistency, and readability while preserving their unique voice.
Whether your organization uses AP Style for public communications or needs help maintaining consistent editorial standards, SP Editing can help you create documents that are clear, professional, and ready for your audience.
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