andatory fields are usually pretty simple to work with. ServiceNow provides simple UI policy and client script methods to make fields and variables mandatory. You may have noticed as you have worked with checkbox variables in the service catalog that these methods don’t apply. The reason for this makes perfect sense if you think about it. A checkbox has only two possible values…true or false. When the checkbox variable loads it is already set with a value of false (unchecked). Because of this, there’s never a situation where a checkbox variable wouldn’t satisfy a mandatory check. It will ALWAYS have a value!
What people usually want in these scenarios is to require a user to select a minimum number of options from a certain group of checkbox variables. In these scenarios, this minimum number of items checked really represents the standard for a mandatory check for that group of checkboxes. There’s not a simple way to handle these situations, but I’ve set up some client script solutions that allow you to perform this type of validation if it is needed.

Mandatory Checkboxes

This onLoad script will place a red mandatory indicator next to the label for a set of checkbox variables. Just paste the script into an ‘onLoad’ catalog client script and set the ‘mandatoryLabelName’ variable below with the Name value of the label variable for your group of checkbox variables. NOTE: This script requires an associated ‘Label’ variable to work with your checkbox variables and will not work in Service Portal. For Service Portal you should simply add a form info message as shown in the script below. See this post for details on how to set up label variables with checkboxes.

‘Mandatory checkbox label indicator’ catalog client script
Name: Mandatory checkbox label indicator
Type: onLoad
Applies to: A Variable Set OR A Catalog Item

function onLoad(){
        mandatoryLabelName = 'checkbox_variables';
        $('status.' + g_form.getControl(mandatoryLabelName).id).show();

This onSubmit script will check a set of checkbox variables to make sure at least some of them are checked. All you have to do is paste the script into an ‘onSubmit’ catalog client script and set the ‘mandatoryVars’ and ‘mandatoryCount’ variable values below with the checkbox variables the script should apply to and the minimum number of checked boxes.

‘Mandatory checkboxes’ catalog client script
Name: Mandatory checkboxes
Type: onSubmit
Applies to: A Variable Set OR A Catalog Item

function onSubmit() {
    //Set the mandatory checkbox variable names and total mandatory count here
    var mandatoryVars = 'option1,option2,option3,option4';
    var mandatoryCount = 2;
    var passed = forceMandatoryCheckboxes(mandatoryVars, mandatoryCount);
    if (!passed) {
        //Abort the submit
        var message = 'You must select at least ' + mandatoryCount + ' options.';
        return false;

function forceMandatoryCheckboxes(mandatory, count) {
    //Split the mandatory variable names into an array
    mandatory = mandatory.split(',');
    var answer = false;
    var varFound = false;
    var numTrue = 0;
    //Check each variable in the array
    for (var x = 0; x < mandatory.length; x++) {
        //Check to see if variable exists
        if (g_form.hasField(mandatory[x])) {
            varFound = true;
            //Check to see if variable is set to 'true'
            if (g_form.getValue(mandatory[x]) == 'true') {
                numTrue ++;
                //Exit the loop if we have reached required number of 'true'
                if (numTrue >= count) {
                    answer = true;
    //If we didn't find any of the variables allow the submit
    if (varFound == false) {
        answer = true;
    //Return true or false
    return answer;