Has anyone ever seen or heard of this approach to a signup page?

soft required field

So the idea is the "Phone number" is not required, however when trying to submit the empty field you would get this message/option (shown above).

To give a little context also, this is for a major well known medical company site that has a lot more personal/private information on it's patients (users) than their phone number! Which was my argument when pushing for it to be simply required (if we really want it) or not as users shouldn't be hesitant on providing that information to us.

This is definitely going to create more user friction/annoyances as the other required fields have the standard asterix and this one does not.

  • 1
    I think the more conventional pattern is to provide an informational type of message explaining to the user why you want to collect this information (and what you might use it for). The correct behaviour is also to determine whether the user wants to provide this information or not before giving them an input field which they can subsequently ignore.
    – Michael Lai
    Commented Mar 31, 2015 at 12:33

5 Answers 5


Are you sure that you're sure?

This is the question you ask your users with this type of strategy.

Business goals

From a business perspective the thinking is:

  • Required field - we must have it.
  • Optional field - provide at will.


The way optional fields are seen by users is:

I can either provide it or not.

If the user is aware of what is optional and what is required, by the time they hit submit, they have already made the decision of whether or not to provide the information.

A simple message like "Please provide a phone number" is confusing (since it wasn't a required field, so why do you ask me to provide it now?) and is highly unlikely to nudge anyone to provide information they have already decided not to provide.

A better strategy

A better strategy is to offer some incentive before the user has pressed submit (at which point anything that would stop her from progressing towards task completion would be annoying).

So perhaps something like a message below the field that shows on focus and says "By providing a telephone number we can contact you in case of emergency" would have far greater conversion.

  • +1 on the incentive. It creates the right, disclosive interaction for users.
    – tohster
    Commented Mar 31, 2015 at 3:35

Conscious Decision

IF the main idea here is to force the user to make a conscious decision to provide or not provide a phone number then maybe you could integrate a radio button group into the control.

Radio Buttons

The first radio button could live alongside the text box for the phone number. Selecting this one would mean they then have to provide some content in the phone box.

The second radio button could have a label saying e.g. "I do not want to provide my phone number".

No Surprises

This approach could work because on load neither radio buttons would be selected and the majority of users are used to having to make a choice when presented with a group of radio buttons. Therefore upon pressing submit they may not be surprised to be bounced back to this control to make a choice.

Also you are forcing them to make that active choice not to provide the phone number, which takes a little more thought than simply leaving a field blank.

Progressive Disclosure

Upon selecting the "I don't want to provide it" option, you could disclose a subtle message reminding of the terrible consequences of not providing one e.g. "Are you sure you don't want us to have your number? We could add you on WhatsApp if you do". They may then get scared and change their mind and provide one.

Basically, provide a more clear approach to what is required/not required but with a little twist as to maybe get more people to provide the info you want but don't require.

Quick mock

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While I've seen it before, I much prefer the yellow highlighting on fields like that. We tend to go green and red for traffic lights, if you should do it, but don't have to yellow fits perfectly.


This is very confusing I have to say, reminds me of the fuzzy logic. Well fuzzy logic is a nightmare for the user, as he would like the system to keep it simple. Also, the user probably saw one or two forms in his life, I guess not a single one behaved as you suggest above.

Bottom line, there is no semi-required like there is no semi-pregnant.


Firstly, put an '*' and some text indicating the field is compulsory and you'll have less need to present people with this unconventional validation. However...only make the field compulsory if (as mentioned be others) there is a strong business case for it.

The other issue with your example is that some users may skip the phone number hoping they don't have to fill it out whilst others may simply forget that field. In the 'forgetting or missing the field' case they may actually have gladly completed the phone number but suddenly they are presented with an opportunity to skip it.

I think it goes without saying that asking for a phone number if it's not compulsory is bad practice - check out http://www.lukew.com/ff/ as he has lots of posts about removing unnecessary complexity from forms i.e. blockers to conversion.

Another option may also be to make the field compulsory but allow nonsense answers as a compromise. That may sound counterintuitive (and slightly against common practice) but it eliminates the mixed message of 'compulsory unless you really really don't want to' that you currently have.

We actually do that for a few forms where I work currently. Sales were insistent on a phone number field but Conversion and UX team members argued that it would increase form abandonment - so including the field but letting users get away with putting in a random (even 3 digit) number and not validating it was the compromise. Not ideal, but it does mean we can gather phone numbers from all those willing but don't scare of people who find that invasive. In short - it's a compulsory field but the input doesn't have to validate correctly (although it must be numerical).

Hope that helps!

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