> ## Documentation Index
> Fetch the complete documentation index at: https://docs.terminus.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Terminus ID field

> A computed field that surfaces the record's system-generated unique identifier, in the format trm0 followed by alphanumeric characters.

<Info>
  The Terminus ID field surfaces a record's built-in unique identifier, in the format `trm0` followed by lowercase alphanumeric characters. It is generated by the system, so submitters never type it.
</Info>

Terminus ID is a **computed** field. Its value is system-generated when the record is first created, the field is always required, and it does not appear as an input a submitter can fill in.

## When to use it

Reach for Terminus ID when you need a stable handle on a record:

* A reliable identifier that outlives any single submission and never changes.
* A `code_field` for an [automated picklist](/reference/picklists/automated), so other taxonomies reference each record by a code that stays put even when its display name changes.
* A dependable value to feed into a [Concatenation](/reference/fields/concatenation) field.

<Warning>
  Do not use Terminus ID when you need a human-friendly or sequential number. Its format is fixed and cannot be configured. Use [Auto Number](/reference/fields/auto-number) for readable, sequential identifiers.
</Warning>

## How it works

Every record carries a Terminus ID, assigned the first time it is created and unchanging from then on. The identifier is unique across your account.

A Terminus ID field surfaces that identifier as a field value, so it can show in the grid, feed into a [Concatenation](/reference/fields/concatenation) field, or serve as the code an [automated picklist](/reference/picklists/automated) stores. The field is not a second, independent identifier: it mirrors the record's own Terminus ID.

## Settings reference

Terminus ID has no configurable settings. The format and value are system-generated and cannot be changed.

## Example

A `Clients` taxonomy uses a Terminus ID field so other taxonomies can reference each client by a stable code:

```yaml theme={null}
name: client_id
type: terminus_id
```

A client record resolves to something like `trm0kf8m2a1q`. An automated picklist on a `Campaigns` taxonomy can then use `client_id` as its `code_field`, so each campaign stores the client's Terminus ID, a reference that survives even if the client's name later changes.

## Gotchas

* **There are no settings.** You cannot change the format, length, or add a prefix or suffix.
* **It is fixed and unique.** The value is assigned once when the record is created and is unique across your account, which is what makes it safe to use as a reference.
* **It mirrors the record's identifier.** It is the record's own Terminus ID made visible, not a separate ID.
* **It is read-only.** The value is generated for you and there is nothing to set or edit in the submission form.

## Related

* [Fields](/reference/fields)
* [Automated picklist](/reference/picklists/automated): commonly uses Terminus ID as its `code_field`.
* [Auto Number field](/reference/fields/auto-number): a sequential alternative when you want readable numbers.
* [Other computed fields](/recipes/other-computed-fields)