Grammar & mechanics

These guidelines follow our Voice & tone principles and help us keep writing across Kiwi.com consistent. Use them to check on details (like spelling) when you write in our official language, American English, and save energy to focus on getting your content right.

Write in the active voice whenever you can.

Use passive voice only when you want to avoid blaming someone or when the subject is less important than what happened.

Kiwi.com’s official language is American English, so use American spelling.

Always include diacritics if they’re there:

Use contractions freely to sound natural and avoid being robotic or overly formal.

But there are some exceptions where the full form is appropriate. For example, if you need to stress something is not possible or to be more formal.

Only use common abbreviations and acronyms.

If something isn’t common, spell it out or explain it first.

Use sentence case in all of your writing. Capitalize only the first word in sentences, headings, buttons, emails, etc. Don’t capitalize after a dash or colon in titles or lists.

Capitalize proper nouns, legal terms, and product names according to their own rules, and also names of sections or buttons when referring to them.

Check our glossary for a full list of Kiwi.com product-related names.

Don’t use all caps unless they’re a part of the design and never use them to emphasize a point.

• To emphasize text, use bold instead.

Use plural by default if there can’t be multiple versions of the copy.

If it’s important to specifically mention that there may be one or multiple items, use the phrase “one or more”.

Use “and” instead of “&” in longer texts as it improves readability and therefore is more inclusive.

But there are a few exceptions if you need to save space, especially in titles and buttons.

Use commas to mimic speech — to add a pause where it’d naturally occur or to separate or highlight parts of a sentence.

Don’t use commas if they don’t serve a purpose, for example after “please” or before and after “unfortunately“ in the middle of a sentence.

If you need to list multiple items, use a serial comma (also known as the Oxford comma).

The only exception is when you use an ampersand.

Use exclamation points sparingly, and only when they serve a purpose — when you talk about a really exciting thing.

Never use multiple exclamation points in a row, and avoid using them in longer sentences altogether.

The rule of thumb for using unusual punctuation is: don’t. If you do, you should make a case for it.

If an item has a symbol or an official abbreviation, use it instead of spelling it out.

Don’t use spaces between single numbers and the things you’re counting unless it helps with readability.

Use full stops (periods) only at the ends of complete sentences. Never use them at the ends of headers or buttons.

Always use curly quotation marks and apostrophes.

Don’t use quotation marks to refer to parts of the interface (buttons, menus, options) — use bold instead.

Use a hyphen (-) for compound words. Don’t use spaces before or after.

Use an en-dash (–) without spaces to talk about ranges of numbers (like times or dates).

But when you write about locations, replace the en-dash with an arrow (→, ⇄) wherever possible and use spaces before and after the arrow.

Use an em-dash (—) instead of commas or colons. Use spaces before and after.

Use emojis sparingly to attract your reader’s attention or emphasize a (positive) feeling, but never to replace words or as the only way to express emotion.

These rules were inspired by emoji guidelines by Content Design London.

Add an emoji at the end of the sentence to highlight the whole message. If you absolutely need to highlight a particular word, put the emoji after it.

Write all numbers as numerals for better readability.

When you write about numerous people or animals, always write thousands, millions, or billions in full. For anything else, M or B is ok, depending on how it reads.

Use commas to separate thousands units.

Write date as day-of-week, month, day, year. When the space is limited, use abbreviations or numerals.

Use the 24-hour clock and UTC time zone to refer to the time in general.

Use an en-dash (–) when referring to a duration in time.

When describing a length of time, use abbreviations.

Use the currency symbol instead of language code.

Place the symbols €, $, and £ before the price, without a space. For other currencies, follow the language standards.

Use lists to present steps or sets of information ideally consisting of 3 or 5 bullet points — if you have more points, consider a table.

Make sure that the items on the list have a parallel structure and context, especially if you create a list of pros and cons.

Align your capitalization and punctuation as well.

• If an item on the list is a complete sentence, capitalize the first word and add a full stop.
• If an item isn’t a complete sentence, don’t use punctuation, but capitalize the first word of each bullet.

If you can’t use an ordered list because of space restrictions and you need to describe the full path to get somewhere, use a single right-facing chevron (>) and bold clickable UI elements.

When you talk to your readers, address them directly and use the second person — you, your.

When your readers need to perform an action, like click on a button, choose an answer to a question we’ve asked, or provide legal consent, use the first person — me, I, my.

When you refer to someone in general, or they haven’t disclosed their gender, use singular they, their.

When you refer to Kiwi.com, use we, us, our as default unless you have to specifically stress our name for clarity or branding purposes.

Write short sentences and put essential info first. Short sentences improve readability. They’re more powerful. They value your reader’s time.

Long sentences that run on and on and are full of commas, colons, and semicolons — and many different clauses — are really confusing and awkward to read for even the strongest readers — just imagine receiving an email with sentences stretching through multiple paragraphs, as long and winding as this one; it’s an impossible read that most people just can’t get through and either scan through it or skip it completely on a busy day — and let’s be honest, every day is a busy day, especially when traveling.

Use a text editor like hemingwayapp.com if you’re not sure how complex your text is.

Always use words and phrases that are easily understandable. Don’t use extra words that don’t serve a purpose.

💡 Check our glossary for the list of common words we use across Kiwi.com_.

When possible, use informal short forms of the words depending on the context and space. Short forms sound more natural and are especially useful for buttons.