Validate from a table, with out showing the values

Im creating a form and I want a column to be valid only if the value input matches a list in another table, but I don´t want the user to select from a dropdown or have any list of valid inputs…
Use case: I have a list of customer with national IDs and if a person fills the form and his national ID does not match the list, I want to show a Not valid message.
Thanks!

0 2 150
2 REPLIES 2

You could try an expression something like below in the valid_if

IF(IN([_THIS], TableName[National ID]), TRUE, FALSE)

Or like AND(TRUE,IN([_THIS],Table[National ID]))

Top Labels in this Space