validation rule fire when phone number doesn't have value (we can left blank also)

Question

this is my validation rule but the thing is if i left blank phone and save it record its fire validation rule but my concern is only number allowed that is working fine but if person dont have phone he can left blank. how to allowed blank

OR( 
    OR( 
        LEN( Phone ) <= 9 ,
        LEN( Phone ) >= 13 
    ), 
    NOT( 
        OR( 
            REGEX(Phone, "[0-9 ]+"), 
            REGEX(Phone, "\\+[0-9 ]+")
        ) 
    ) 
)

Answer 1

You say that the length of the phonenumber can't be lower than 9. That is the problem. You should combine that with the 0. Maybe like this:

OR( 
        AND(
           LEN( Phone ) <= 9 ,
           LEN( Phone ) <> 0
        ),
        LEN( Phone ) >= 13 
    ),

Answer 2

Try this

AND(OR( 
    OR( 
        LEN( Phone ) <= 9 ,
        LEN( Phone ) >= 13 
    ), 
    NOT( 
        OR( 
            REGEX(Phone, "[0-9 ]+"), 
            REGEX(Phone, "\\+[0-9 ]+")
        ) 
    ) 
),NOT(ISBLANK(Phone)))

Answer 3

Modify your regex as per requirement and replace with below regex.

Given regex is for pattern '(555) 555-5555'.

IF(NOT(ISBLANK(Phone)),NOT(REGEX(Phone, "[0-9+\\-\\(\\)\\s]{14}")),false)

This validation formula also save blank field for Phone type field. If you still get error then you have to change field's page property in edit page layout and uncheck the field property 'Required'.

Uncheck 'Required' in Edit Page Layout :