The AP Numbers Rule Agencies Should Standardize First

For most agency copy, the first rule to lock down is simple: spell out small numbers, use numerals for larger ones. That one standard removes a surprising amount of inconsistency across blog posts, social captions, pitch decks, landing pages, and email campaigns.

When to Spell Out Numbers in AP Style

In general AP style, spell out whole numbers from zero through nine.

Use this treatment in ordinary sentence copy:

• The campaign generated three strong creative directions.
• The team reviewed seven homepage concepts.
• We recommended one primary message and two supporting proof points.
• The client approved nine social posts for the launch.

This matters because small-number inconsistency is easy to miss when multiple writers, strategists, freelancers, and AI tools touch the same account. One draft says “3 concepts,” another says “three concepts,” and suddenly the client’s content feels less controlled than it should.

Also spell out numbers when they begin a sentence:

• Incorrect: 12 revisions later, the team approved the final layout.
• Better: Twelve revisions later, the team approved the final layout.
• Often best: The team approved the final layout after 12 revisions.

That last rewrite is usually the cleanest option for agency copy. It keeps the sentence natural while avoiding a clunky spelled-out number.

For casual expressions, spelling the number often reads better too:

• Thanks a million.
• She had a thousand ideas.
• The brand needed a second look.

The goal is not to make every sentence feel “rulesy.” It is to create a default your team can apply quickly without debating every small number in every draft.

When to Use Numerals Instead

Use numerals for 10 and above in standard running copy:

• The audit covered 14 competitor websites.
• The campaign included 22 email variations.
• The redesign reduced the navigation from 11 items to six.
• The team delivered 10 landing page wireframes in the first round.

Notice the mixed example: “11 items to six.” That may look odd at first, but it follows the core AP pattern unless another rule applies. For agencies, this is where a shared standard is useful. Without one, editors often “clean up” numbers based on personal preference, which creates more inconsistency across client work.

Numerals are also better when the number needs to stand out for scanning, especially in performance-oriented copy:

• 10 ways to improve your onboarding flow
• 12 questions to ask before a rebrand
• 25 subject lines for a product launch

For headlines, ads, and web modules, numerals often improve readability. If your agency follows AP closely, keep the same zero-through-nine rule as your baseline, then define any client-specific headline preferences separately.

Quick Decision Tree for Everyday Copy

Use this as the fast internal check before copy goes to review:

1. Is it a whole number from zero through nine?

Spell it out.

1. Is it 10 or higher?

Use a numeral.

1. Does the number start the sentence?

Spell it out, or rewrite the sentence so the number does not come first.

1. Is it part of a headline, list title, or scannable web element?

Prefer the format your agency or client has standardized, but do not switch styles within the same asset.

1. Are two related numbers in the same sentence treated differently under AP?

Keep the AP treatment unless clarity suffers.

That is the everyday foundation of ap style guide numbers: one clear default, applied consistently before the more specific number categories come into play.

AP Style for Ages and People-Related Numbers

People-related copy is where small inconsistencies become noticeable fast: bios, case studies, campaign landing pages, social captions, press releases, donor stories, recruiting ads. A clean age rule keeps that work from sounding like it came from five different writers.

Ages Always Use Numerals

In AP style, ages use numerals every time, even for numbers under 10.

Use:

• The founder is 7.
• She is 4 years old.
• The program serves children ages 3 to 5.
• A 9-year-old joined the class.
• The agency interviewed 6 teenagers for the campaign.

Avoid:

• The founder is seven.
• She is four years old.
• The program serves children ages three to five.

This is one of the easiest places for AI tools, freelancers, and internal reviewers to drift, because it conflicts with the broader “spell out one through nine” rule. If your team maintains client-specific editorial notes, call this out separately under ap style guide numbers so age references do not get “corrected” back to words during review.

Hyphenating Ages Used as Modifiers

Hyphenate an age when it appears before a noun and works as a compound modifier.

Use:

• a 6-year-old student
• the 42-year-old CEO
• a 10-month-old product
• a 3-year-old initiative

Do not hyphenate when the age comes after the noun.

Use:

• The student is 6 years old.
• The CEO is 42.
• The product is 10 months old.
• The initiative is 3 years old.

Also note the noun form:

• The 6-year-old smiled for the camera.
• The 42-year-old launched her second company.

That construction stays hyphenated because the phrase is functioning as a noun. For agency teams, this matters in high-volume content like nonprofit impact stories, healthcare profiles, education marketing, and founder-led PR, where the same person may be described across multiple assets.

Avoiding Inconsistent People Descriptions Across Client Work

Age rules are only one part of people-related consistency. The bigger agency challenge is making sure every client’s human stories feel intentional, not patched together across tools and contributors.

For example, one client may prefer:

• “children ages 5 to 12”
• “older adults”
• “first-year students”
• “team members”

Another may require:

• “kids ages 5-12”
• “seniors”
• “freshmen”
• “employees”

AP can standardize the number treatment, but client voice still determines the surrounding language. That distinction is especially important when your agency is producing bios, testimonials, DEI content, patient stories, student profiles, or community impact reports.

A practical review pass should ask:

• Are all ages in numerals?
• Are compound age modifiers hyphenated?
• Are person descriptors consistent with the client’s preferred terminology?
• Does the same audience group get named the same way across web, email, social, and PR copy?

That last point is where brand consistency shows up. “A 17-year-old student,” “a teen participant,” and “a young person” may all be grammatically fine, but they do not carry the same tone. For agencies scaling content across multiple clients, the win is not just correct AP style — it is making sure every person description sounds like it belongs to that client.

AP Style for Dates, Times, and Calendar References

Once people-related numbers are locked down, calendar copy is the next place agency teams tend to drift—especially across landing pages, email invites, social captions, webinar promos, and paid ads.

Dates Without Ordinal Endings

In AP style, dates use numerals without ordinal endings.

Use:

• Jan. 5
• March 12
• Sept. 30

Avoid:

• Jan. 5th
• March 12th
• September 30th

This matters because AI tools often default to more conversational date formats, especially in event copy: “Join us on April 3rd” or “Launching May 1st.” For agencies managing multiple client voices, this small inconsistency can make copy feel less polished—even when the message is right.

A simple client rule to encode: “Use AP-style dates with no st, nd, rd, or th.”

Months, Years, and Commas

AP style treats months differently depending on whether they appear with a specific date.

When a month is used with a day, abbreviate only these months:

• Jan.
• Feb.
• Aug.
• Sept.
• Oct.
• Nov.
• Dec.

Spell out:

• March
• April
• May
• June
• July

Examples:

• The campaign launches Jan. 8.
• The report goes live Sept. 14.
• The client workshop is scheduled for March 6.
• The new site launches July 22.

When using only a month and year, spell out the month and do not use a comma:

• January 2026
• September 2025
• March 2024

When using a month, day, and year, place a comma after the day and after the year if the sentence continues:

• The campaign launched Jan. 8, 2026, across three markets.
• The event is scheduled for March 6, 2026, at the client’s headquarters.

For ap style guide numbers, this is one of the easiest rules to turn into a reusable brand preference because it shows up everywhere: nurture emails, event pages, press releases, decks, and announcement posts.

Times, a.m./p.m., and Event Copy

AP style uses lowercase a.m. and p.m. with periods.

Use:

• 9 a.m.
• 2:30 p.m.
• 11 p.m.

Avoid:

• 9 AM
• 2:30pm
• 11 P.M.

For times on the hour, omit the minutes:

• 10 a.m., not 10:00 a.m.
• 4 p.m., not 4:00 p.m.

Use noon and midnight instead of 12 p.m. or 12 a.m. when clarity matters.

For event copy, consistency is the bigger operational issue. One client page might say “Webinar starts at 1 PM,” while the reminder email says “1:00 p.m.” and the social post says “1pm.” That fragmentation is exactly what makes AI-assisted production feel messy.

A clean event listing might read:

• Tuesday, Sept. 10, at 1 p.m. ET
• Thursday, March 21, at noon CT

If your agency uses AI to draft event assets, add these calendar rules directly into the client’s style instructions so every first draft starts closer to publish-ready.

AP Style for Percentages, Money, and Measurements

Once calendars are tidy, the next consistency leaks usually show up in case studies, ad copy, landing pages and product specs — the places where numbers carry commercial weight.

Percentages and the Percent Sign

In AP style, use numerals with the percent sign: `7%`, `12.5%`, `100%`. No space between the number and `%`.

For agency work, this matters most in performance copy:

• `Email signups increased 18%.`
• `The campaign delivered a 4.6% conversion rate.`
• `Paid search drove 32% of qualified leads.`

Avoid mixing `percent` and `%` across the same client’s assets unless there’s a specific brand reason. A case study that says `12 percent lift` in one paragraph and `12% lift` in the pull quote feels stitched together, especially when multiple writers or AI tools touch the copy.

For nonspecific uses, spell it out:

• `A small percentage of users abandoned checkout.`
• `The discount applies to a percentage of the total order.`

Currency, Large Sums, and Business Results

Use the dollar sign and numerals for specific amounts:

• `$5`
• `$49`
• `$1,250`
• `$3.5 million`

Skip unnecessary zeros in general copy: write `$12`, not `$12.00`, unless cents are relevant to pricing, retail or financial detail.

For amounts under a dollar, AP typically uses numerals with `cents`:

• `The cost dropped to 99 cents per unit.`
• `The fee increased by 5 cents.`

For large sums, use `million`, `billion` or `trillion` instead of long strings of zeros:

This is especially useful in client results. `Generated $2.4 million in pipeline` is easier to scan than a full numeral, and it keeps business claims looking polished across decks, web copy and sales enablement.

Avoid shorthand like `$2.4M` in AP-style editorial copy unless the client’s brand system explicitly uses it. It may work in a dashboard or pitch slide, but it often looks too informal in a press release, case study or executive byline.

Dimensions, Distances, and Other Measurements

Use numerals with measurements, and spell out the unit in running copy:

• `The booth included a 10-foot display wall.`
• `The package weighs 3 pounds.`
• `The office is 4 miles from downtown.`
• `The video wall is 12 feet wide.`

When the measurement modifies a noun, hyphenate it:

• `a 6-foot banner`
• `a 3-mile radius`
• `a 12-ounce bottle`
• `a 300-by-250-pixel ad placement`

For dimensions, use `by` in prose rather than the multiplication symbol:

• `a 5-by-7 postcard`
• `a 10-by-20 trade show booth`
• `a 300-by-600-pixel display ad`

That last example is where agency style often drifts. Designers, media buyers and copywriters may each write specs differently: `300x600`, `300 × 600`, `300 by 600`, `300-by-600`. For polished client-facing copy, standardize the AP-style prose version. Save platform-specific shorthand for media plans, spreadsheets and ad ops documentation.

AP Style for Ranges, Comparisons, and AI Output QA

Once the core number formats are locked, the next consistency risk is how ranges and comparisons get phrased—especially when AI is drafting across multiple client accounts.

Using Hyphens, En Dashes, and From-To Constructions

For AP-style agency copy, keep ranges simple and consistent: use a hyphen with no spaces for compact ranges, and use words when the sentence already introduces the range.

The big agency rule: don’t let every writer, freelancer, or AI tool choose its own range style. Pick the default once per client, then enforce it everywhere—landing pages, decks, email nurture, social captions, and reports.

Keeping Comparative Numbers Clear

Comparative copy is where technically correct numbers still create messy messaging. A few small wording choices can change the meaning of a claim.

Use clear comparison language:

• `Increased by 25%` means the result grew 25% from the original number.
• `Increased to 25%` means the final result was 25%.
• `Up to 50% faster` means 50% is the maximum, not the average.
• `More than 100 customers` is clearer than `over 100 customers` when precision matters.
• `Fewer than 10 revisions` works for countable items; `less than 10 minutes` works for time or quantity.

For client-facing performance copy, always include the baseline when the comparison needs it: `cut onboarding time from 10 days to 6 days` is stronger than `cut onboarding time by 40%` if the audience needs to understand the real-world impact.

This is especially important for agencies producing case studies, ads, sales sheets, and founder LinkedIn posts. A loose comparison can make a result sound inflated, vague, or inconsistent with the client’s approved claims.

Turning Number Rules Into an AI Brand Guardrail

AP style guide numbers rules should not live only in a shared doc that writers check after the draft is done. For AI-assisted production, turn them into account-level guardrails.

For each client, define:

• Preferred range style: hyphen, en dash, or written construction
• Approved comparison phrases: `more than`, `fewer than`, `up to`, `from X to Y`
• Disallowed patterns: `from X-Y`, `between X-Y`, mixed dash styles
• Claim requirements: whether comparisons need a baseline, source, or approved proof point
• Client exceptions: any brand-specific deviation from AP

That is the difference between “AI helped us draft this” and “AI created another QA pass for the team.”

Aethera makes this practical by ingesting the client’s brand standards once, then applying those rules across AI-generated outputs. So if one healthcare client wants strict AP hyphenated ranges and another SaaS client prefers en dashes in web copy, your team does not have to remember it manually every time. The guardrail travels with the client, not the individual writer.