# Auto Incrementing Field

_How to add and configure an Auto Incrementing Field in the {{Notebook}}
Editor._

---

## What This Field Does

An Auto Incrementing Field generates sequential string identifiers
automatically — such as specimen numbers, context numbers, or
catalogue IDs. Each new record receives the next number in the
sequence (e.g., 001, 002, 003). The value is auto-generated and
cannot be edited by data collectors.

## Adding the Field

To add this field, open the
[ADD A FIELD dialog](../shared-settings/adding-a-field.md), navigate to the
**NUMBERS** tab, and click the **Auto Incrementing Field** card. Then click the
**ADD FIELD** button in the lower right.

```{screenshot} field-types-design/unique-id-01-add-field.png
:alt: Adding an Auto Incrementing Field — the NUMBERS tab in the ADD A FIELD dialog
:align: right
:width: 100%
```

## Configuring the Field

Click the field's **grey header bar** to expand it and see its settings.
For an overview of the settings shared by all fields — including Label,
Helper Text, Field ID, and the field toolbar — see
[Field Identity](../shared-settings/field-identity.md) and
[Field Toolbar](../shared-settings/field-toolbar.md).

Give the field a meaningful Label, review the auto-populated
Field ID, and add any desired Helper Text.

```{screenshot} field-types-design/unique-id-02-configured.png
:alt: Auto Incrementing Field configuration in the {{Notebook}} Editor
:align: right
:width: 100%
```

### Auto Incrementing Field-Specific Settings

The Auto Incrementing Field provides one configurable setting:

| Setting                            | What It Does                                                                                                        |
| ---------------------------------- | ------------------------------------------------------------------------------------------------------------------- |
| **Number of digits in identifier** | The number of digits in the generated identifier, with leading zeros for padding (e.g., 5 digits produces "00001"). |

### Shared Field Options

Configure any of the shared field options as needed.

For settings shared across all field types — including Required,
Annotation, Uncertainty, Conditions, Copy value to new records,
and Display in child records — see
[Field Options](../shared-settings/field-options.md).

## Tips

- **The identifier is a padded string, not a number.** A 5-digit
  counter generates "00042", not 42. This preserves leading zeros in
  exports and avoids numeric sorting issues in spreadsheets.
- **Wrap in a Templated String** to build meaningful composite
  identifiers — for example, "SAMPLE-00042-2026" combines the auto-
  incremented number with a prefix and year.
- **Ranges are configured per-device in the data collector.**
  Each device is given a non-overlapping range of numbers
  (e.g., Device A: 1–500, Device B: 501–1000) so identifiers
  stay unique without network coordination. Data collectors set
  their own ranges — typically following a protocol defined by
  the project leader. To configure ranges, open "Settings" in
  the {{FAIMS}} data collector and use the "Edit
  auto-incrementers" panel. Each Auto Incrementing Field has
  its own button, which opens a dialog where you set start and
  stop values, add new ranges, and update the last used value.
  If a range is exhausted, a new one can be added on that
  device.
- **Plan your numbering scheme before deploying.** Once a range
  is created on a device it cannot be edited — you can only
  close it and add a replacement. Because {{FAIMS}} is designed
  for off-line use, no automatic conflict checks are made
  across devices, so ensure ranges do not overlap when
  assigning them.