Hi BB,

Try,

    @api.constrains('phone', 'owner')

    def check_phone_owner_uniq(self):

        for record in self:

            duplicate_records = self.search([

                ('phone', '=', record.phone),

                ('owner', '=', record.owner.id),

                ('id', '!=', record.id)

            ])

            if duplicate_records:

                raise ValidationError("You cannot have two tenants with the same phone number for the same owner!")