When creating a new "Account" in Dynamics 365 Sales, if Dual Write is enabled for this entity, the record is synced to Dynamics 365 F&O as a "Customer". As in Dynamics 365 Sales, the Account entity does not enforce validations on Account Address fields, users can freely type whatever City, State, District, Zipcode, Country they wish. As these fields are enforced by Data Lookups on D365 F&O, if the user does not insert a valid field in Sales (valid = existing in F&O), the record creation fails, due to a data sync failure.

If a deployment of F&O and CE is expected in enterprise environments with harmonized and consistent data sync among such relevant entities, data lookups and validations should be enforced and enabled in CE when creating an Entity Address, so users are not disrupted while creating master data, and a recurrent customization is not required for every single deployment.

Thank you.