Create a validation rule:
Rule Name: Contact_must_be_in_Account_ZIP_Code
Operator: AND (return true if both conditions are true)
Define two error conditions:
The contact is associated with an account id
Hint: Use the ISBLANK and NOT functions.
The contact mailing zip code is different than the account shipping zip code
Hint: Use the API names (MailingPostalCode and ShippingPostalCode) and the <> (Not Equal) operator.
Enter an error message for the validation rule

BELOW IS THE ERROR
We can't find a reference to the account 'ShippingPostalCode' field in the validation rule.

Create a validation rule:
Rule Name: Contact_must_be_in_Account_ZIP_Code
Operator: AND (return true if both conditions are true)
Define two error conditions:
The contact is associated with an account id
Hint: Use the ISBLANK and NOT functions.
The contact mailing zip code is different than the account shipping zip code
Hint: Use the API names (MailingPostalCode and ShippingPostalCode) and the <> (Not Equal) operator.
Enter an error message for the validation rule

BELOW IS THE ERROR
We can't find a reference to the account 'ShippingPostalCode' field in the validation rule.