If a prospect creates an account on your account creation page but never starts an application, they may not have a First Source value. You can create an Account Creation origin source to account for this circumstance by comparing the person created date with the delivered date of the account creation mailing. If those dates match, a rule can add an Account Creation interaction, and an origin source can use that interaction as its source.
⭐ Get Inspired
This article was adapted from a post by Technolutions staff in the Slate Community Forums' Get Inspired space. Have a great idea for a Get Inspired post? Let us know!
Creating an Account Creation interaction code
Go to Database → Activity / Interaction Codes.
Select Insert.
Configure the following settings:
Status: Active
Type: Interaction
Code: Enter a computer-friendly name for the code, like
account_creation.Label: Enter a human-friendly name for the code’s label, like
Account Creation.
Select Save.

Creating a rule to add the interaction
Create the rule
We start by creating a new rule:
Go to Database → Rules.
Select New Rule.
Configure the following settings:
Name: Enter a name for the rule, like
Add Account Creation Interaction.Type: Configurable Joins
Category: Records
Base: Person
Rule Type: Interaction
Rule Trigger: Upon Update (Deferred)
Status: Preview
Select Save.
Create a subquery filter
In the rule, we’ll add a subquery comparison filter that compares the person created date to the account creation message delivered date.
On the rule overview page, select Subquery Filter.
Configure the following settings:
Status: Active
Name: Enter a name that describes what the subquery filter is testing for, like
person created = account creation message delivered date.Aggregate: Comparison
Exports: Add the following exports:
Person → Created Date
Messages → Delivered Date (creates a join to the Messages base)
For both date exports in the comparison, edit the export formatting:
Format Type: Date
Format Mask:
MM/dd/yyyy
Field 1: Person Created Date
Operator:
=Field 2: Messages Delivered Date
Filters: Create a filter for Message Mailing → Name
INSystem - Account Creation. (Creates a join to the Message Mailing base).
Select Save.

Configure the rule action
Add any additional filters needed for your process, such as a person created date threshold. Upon Update (Deferred) requires a qualifying record update; the passage of time alone does not trigger the action. See Choosing a Rule Trigger.
In the action section, select the user, the Account Creation interaction code, and the subject.
Select Save.

When the rule is ready to run, edit the rule, set Status to Active, and save it. To process existing records after you add or change the rule, see Retroactive Refresh.
Creating the origin source
Go to Database → Origin Sources.
Select Insert.
Configure the following settings:
Status: Active
Summary: Enter text that appears as a human-friendly origin source summary, like
Account Creation.Origin Group: First Source
Source Type: Interaction
Source: Select the account creation interaction you created earlier.
Category: Enter a human-friendly origin source category name, like
Account Creation.
Select Save.

If your database does not already have a First Source origin group, go to Database → Origin Groups and create one.

📝 Note
Slate calculates Origin Sources overnight in production environments for person records updated within the past 48 hours. Origin Source calculations do not run in test environments. For each Origin Group, Slate assigns both a first source and a last, or most recent, source.