Error

Use an error to let users know when something has gone wrong and needs their attention. 

Warning

Use a warning when you need to alert users to potential issues that could impact their experience. These messages are preventative — they help users take action to avoid negative outcomes. 

Neutral

Use a neutral prompt when you need to guide the user or give additional context.

Neutral prompts can transition to a success or error message when used in a form.

Success

Use a success prompt to communicate that an action or process was completed successfully. These provide positive reinforcement and closure for the user.

You can use a status icon alongside the message — just make sure to use one relevant to the message.

Proposition

Use a proposition to encourage the user to take an action that might benefit them.

These should only appear in list items. The feature or benefit should be clearly related to the action in the list.

Only include a proposition if it’s relevant to what the user is already doing. If we show too many of these prompts, or they feel off-topic, we risk undermining trust and the experience feeling like spam.

Links

Avoid adding a link to an inline prompt. These messages should help users complete their current task, not take them to another screen unless absolutely necessary.

Inline propositions should never include a link. This is because they’re designed to supplement an action in a list item with an offer or benefit. 

Real-time checks

Inline prompts are also used when forms need to check something in the background, like verifying an account number is real.

We’ll show a loading message and icon while waiting for the check to finish.

• Only use background checks for things that need to be verified with external systems, like bank account numbers or IBANs.
• Use a neutral prompt to tell users upfront when we’ll check something.

• Don't use these types of checks for every field.

Error

With any error message, be clear. Something has gone wrong and so the job of the prompt is to communicate what’s happened and how it can be resolved.

• Clearly state the issue – start by explaining what’s gone wrong.
• Tell the user how to fix it – be specific and actionable.
• Use an impartial, helpful tone – don’t blame the user for any mistakes.

Warning

Warnings help the user prevent future issues. They need to be clear and concise.

Use an impartial tone and try to distill your warning down to two parts:

• Explain the potential issue – start by telling the user what could go wrong.

• Give clear guidance – explain what the user can do to avoid a negative outcome.

Success

Although you're delivering good news, keep your message concise. This prompt only relates to one component, so avoid an over the top celebratory tone.

• Confirm the good news, but keep it brief and factual.

• Avoid over-celebration — a simple confirmation is enough.

Neutral

Keep the tone factual and straightforward. Focus on providing clear, relevant information that helps the user understand their situation or options. We don’t want to overwhelm them with unnecessary detail.

• State the key fact – keep it short and clear.
• Make important details easy to scan – if applicable, highlight relevant dates or amounts.

• Avoid unnecessary explanation – users should understand this at a glance.

Proposition

These messages should feel like helpful suggestions. Keep them short, relevant to what the customer is doing, and easy to scan.

Use a warm, inviting tone but don’t overdo it. The benefit to the user should be obvious and immediate. Avoid wordplay or anything that sounds like a hard sales push.

If the feature is genuinely helpful, including the benefit in plain English will do the work for you.

• Frontload the benefit — make the value clear in the first few words.
• Match the tone to the context — friendly and informative, not pushy.

• Don’t use vague phrases like “Check this out”.
• Don’t oversell — if the feature is useful, you won’t need hype.