Use a colon when giving examples if it helps make the copy easier to read.

Example

Add the sales tax components that make up the combined rate: component names, agencies, and percentages.

Use a colon to introduce a list when the introductory text is a complete sentence.

In general, don’t use colons in headlines and subheads, even when you’re introducing a list. If you feel like you need a colon in a heading, see if there’s space for a subheading instead.

When using an abbreviation with a colon, include the period.

Example

Enter invoice no.:

In this example, it might be more conversational to spell out “number.”

If the phrase after a colon is a dependent clause, don’t capitalize the first letter after the colon.

Example

To help track your business, import your information: customers, vendors, chart of accounts, and products and services.

If the phrase after a colon is an independent clause, capitalize the first letter after the colon.

Example

All bank and credit accounts don’t automatically update nightly: Check with your financial institution.

In this example, it’s probably even better to use a period. This helps keep the copy conversational and simple.

Example

All bank and credit accounts don’t automatically update nightly. Check with your financial institution.