---
sourceDocument: Yokohama Build or modify applications
sourceDocumentLink: https://servicenow-prod.fluidtopics.net/r/yokohama/application-development

 Release :

    - yokohama

ft:locale :

    - en-US

ft:publication_title :

    - Yokohama Build or modify applications

ft:clusterId :

    - cadev

bundleId :

    - cadev

workflow :

    - Development, Data, and Analytics


---

# Data table guidelines for Guided Application Creator

# Data table guidelines for Guided Application Creator {#ariaid-title1}

* Release version: Yokohama
* 
* Updated January 30, 2025
* 
* ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 1 minute to read

When you create an application in Guided Application Creator, you can optionally create a
data table for your application. To ensure that you are within the limits of your subscription and
that your application performs as expected, consult the data table guidelines before you create a
data table.  
Note:  
ServiceNow AI Platform application subscriptions include custom table entitlements. You can create custom tables for any purpose, up to the entitlement limit in the subscription. To learn more about how your usage
administrator maps the custom tables that you create to subscriptions, see [Map custom tables to a product subscription in Subscription Management](https://www.servicenow.com/docs/access?context=allocate-custom-table-subsc-app-v2&version=yokohama&pubname=yokohama-platform-administration&ft:locale=en-US).

## Spreadsheet guidelines {#ariaid-title2}

One way to create a new data table in Guided Application Creator is to upload an external
spreadsheet. Prepare your spreadsheet beforehand so that you can transfer your data seamlessly
and build custom applications faster.
Ensure your spreadsheet is:

* Formatted with horizontal columns and a header label for each
* Saved as an XLSX file type
{#spreadsheet-guidelines__ul_vxf_w33_ghb}

For example, format your spreadsheet as follows.

In Guided Application Creator, you would designate the second row as the header row
so that Client name and Phone number are
uploaded as table fields.

## Table extension guidelines {#ariaid-title3}

One option for creating a data table in Guided Application Creator is to copy an existing data
table and then add more fields to the newly created table. Before you extend a data table,
review the extension model for the table so that you can track which database tables are created
after extension.
Extending a base table incorporates all the fields of the original table and creates system fields for the new table. If they are in the same scope or if they can be configured from other scopes, you can extend tables that are
marked as extensible.

For more information on extension models, see [Table extension and classes](https://www.servicenow.com/docs/access?context=table-extension-and-classes&version=yokohama&pubname=yokohama-platform-administration&ft:locale=en-US).

## Table creation guidelines {#ariaid-title4}

You can optionally create a new table in Guided Application Creator, but it's possible to
create more custom tables than your subscription permits. To ensure that you remain within the
limits of your subscription, review the custom table entitlements for your
organization.