How to Add a Custom Field to a Standard Business Central Table

Prerequisites for Adding a Custom Field

Please see my blog post "A Step-by-Step Guide to Connecting Visual Studio Code with Your Business Central Sandbox".

You may not always know which table you would like to extend, especially if you are new to Business Central development.

There is an easy to way to find out which table and page you would like to extend, whilst in Business Central, go to the page you want to add a field to and press Ctrl + Alt + F1 (fn + control + option + F1 if you are on a mac).

This will bring up the page inspection, this will not only tell you the table you need to extend but also the page where to add your new field.

Steps to Add a Custom Field

1: Create a New Extension

Within VS Code, click on "New File" highlighted

1. 

   
   

2. Make a note of the object range (idRanges) found within your app.json file:

   
   

   

3. In your file, type TT and it will bring up several options, in this case we need Table Extension. Give your object an Id (which has to be unique within your project, a name and define which page you are extending:

4. Now we had add the field to the table, we need to add it to the page so that the end users can see & use the field.

Repeat above by adding a new file and instead of typing TT, type TP, to extended a standard page, we need to use a page extension:

Here we have several options, we can add it before a field, after a field, at the start of a group, end of a group or in its own group. Within the layout section, you can define where your field needs to go:

In our example, lets just add it to the last of the General section.

You need to add the line ApplicationArea = All; otherwise it will not show.

If you wanted to be specific and add it after a certain field, it would look like this:

5. If you save everything and publish, Navigate to the customer card, you will see your new field is present ready to use.

You need to select the datatype which is best for your example. Here is a link to all of the available fields types you can have:

https://learn.microsoft.com/en-us/dynamics365/business-central/dev-itpro/developer/methods-auto/fieldtype/fieldtype-option

I hope this helps you begin adding new fields in Business Central, If there is something would like me to make a blog on please let me know.