Use a colon when giving examples if it helps make the copy easier to read.
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.
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.
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.
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.
All bank and credit accounts don’t automatically update nightly. Check with your financial institution.