A custom value is a named variable that holds one value for the whole sub-account. Typical examples are the business name, support email, main phone number, booking link, review link or a legal disclaimer. You insert it anywhere merge tags work, and when you change the value in one place, every email, SMS template, funnel page and workflow that uses it picks up the change.
The difference from a custom field: a custom field stores a different value on each record, while a custom value is the same everywhere in the sub-account. HighLevel's own rule of thumb is to use a custom value when you want to reuse the same information.
In practice
You manage custom values in the sub-account's Settings, under Custom Values (as of October 2026), where you can add, edit, delete and group them in folders. A custom value's merge tag looks like {{custom_values.booking_link}}, and the picker in the editors inserts it for you.
Agencies lean on custom values to make snapshots reusable. The snapshot's emails and funnels reference {{custom_values.business_name}} and similar values, and after loading the snapshot into a new client's sub-account you only fill in the values. The catch is checking that every value actually got filled in for every client, which means opening each sub-account's settings.
Where it shows up in RGS Tools
Field Finder's custom values viewer lists every custom value with its current value, side by side with the sub-account's custom fields, so an empty or stale value stands out. CSV export saves fields and values for a sub-account to a spreadsheet.