I’m exploring copying data from a contact or company when an associated deal is created. For example, we have a custom “lead source detail” on a contact record and would like that information to copy over to the deal, similar to how Deal Name automatically is populated. I don’t believe I can copy a property value from a contact to a deal, but I’m open to being proven wrong or interested if you’ve encountered a different solve for this situation.
Hi @JillianMolina,
This requires workflows and can be set up easily. In a contact based workflow, enroll contacts when your custom property is know AND Number of associated deals is known. Enable reenrollment for both. Then use the “Copy property value” workflow action, to select your custom propert my on the contact object, then the target property. That’s it 
If you’re looking for something that auto populates directly in the deal create form, you’re right, this is not possible.
Best regards
Thank you Karsten, for both confirming the deal form doesn’t support the data append, and providing a solution!