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Custom Field Validation

Field Validation allows you to accept only the data that meets your required format. You can choose from predefined validation types or create custom validation codes. The predefined types are:

  • alpha – only letters
  • alpha numeric – letters and digits
  • alpha space – letters and white spaces
  • alpha numeric space – letters, digits and white spaces
  • full name e.g. John Doe – the value must contain at least one space character
  • regular expression – add a regex code to define your own validation code
  • numeric – only digits

Field validation


  1. Dear Sir,

    I am unable to set field validation. None of them is working, please make it happen. I am in platinum plan. Also give me guide lines to make first letter capital for entry into short field.


    1. Hello! You will need to create a script which function ( called toUpperCase() ) will automatically create the first letter capitalized. The script will be placed in Settings – Advanced -Form Tab – Scripts. Regex codes are for validating the input, not for changing the input. When users submit the form, our system generates an error that it has the incorrect structure. Users will need to go back to the field and type again. If you have further questions regarding this subject, please contact us.

  2. There was a comment and question above on SSN field validation with the dashes. Here you go!


  3. Hi, is there a way to put custom validation for a set of data? For example, the email a person keys has to be from this list of emails (from my database)

    1. Hi Joan!
      If your database contains a very large amount of data you will need to connect your form to your external database. This can be achieved with our Virtual database and dynamic prefill feature, which is available on our Enterprise plan. For more details about our corporate plans, please request a demo to receive more details.

      On the other hand, for a smaller list you can use Field Rules applied on your email field.

      Thank you!

  4. How can I input custom regex message for that field?

    This value is not validated by validator “regex” seems not telling user what exactly the format should be.

    1. Hello Alvin,

      Our apologies for the late reply.

      If you do not need all those information collected through the form, make sure that only the relevant fields are set to be required. Click on any field in your Form Editor to open its Edit Field panel on the left side of the page and uncheck the Required option.

      Also, you can eliminate empty fields from the email notification.

      Thank you!

    1. Hello Jill!
      To hide the information that is typed in the field behind dashed, may I suggest you add a Password field to the form and rename it to SSN. But be careful not to use the field before or after an email field, for safety reasons. If you require further assistance, don’t hesitate to contact us at support[at]

  5. hi, i want a validation for a phone number this exact way:

    this means 12 numeric digits, NO spaces, no dash, no plus

    can u please help?

    1. Hello Talal!

      I apologize for replying this late. Customer support service goes faster if you contact us via our contact page or use the live chat window, when it appears on our platform during working hours. Now regarding your inquiry.

      Add a Number field to your form and make sure it uses the numeric validation. Next, go to the additional settings of the field, located on the second tab. Use the boxes to set the minimum and maximum length of the accepted input to 12, which is the number of digits (or characters) the phone number you provided in the example. Once you’ve done this, form users will not be able to submit the form unless they provide their phone number in the correct format.

      I hope this helped. For more assistance, don’t hesitate to contact our support specialists.


  6. I need to create a password reset request form. Our pass word requirement AlphaNumeric with at least 1 capital letter and at least one special character ie. !.@# etc. Can be in any order… I don’t see anything that would quite accomplish that…

    Thanks for any assistance.


    1. Hi Russ!

      I’m sorry but at this time we don’t have one that lets you randomly add a word that fits that description.

      You can create a custom field that will request those characters, but your users would have to create their password in the exact order you specify, which doesn’t leave much room for them to come up with a secure or original password.

  7. I’m not sure why but this web site is loading incredibly
    slow for me. Is anyone else having this problem or is it a
    problem on my end? I’ll check back later and see if the problem still exists.

    1. Hello Tony!

      Are you referring to the number format of the Phone field? Because if that is the case, you may click the field within the Form Editor and use the Number Format drop down that appears in the Edit Field panel, on the left. Read more in our documentation at:

      For further assistance, don’t hesitate to contact our Support Team at or via our contact form.


  8. I have a custom field validation in my form that must be an exact 4 digit number to submit (essentially a code). If someone enters the incorrect numbers, the error message reads “Expected input: custom” Is there a way to change that to make it make more sense to the visitor? I’d like it to possibly read “Invalid code” or something to that effect.

    1. Hello Mike!

      To change the text of the error message, go to Form SettingsTranslations section of your form and hit the Add Language button. Select English and hit Done. Next, hover over the added language until you see the Customize button on the right. Click Customize and scroll down to System Messages, within the lightbox. In System Messages, look for the line Expected input and type “Invalid code” in the input box on the right. Afterwards, scroll down until you see the line custom and change it to “ ” (which will add a space instead of the text “custom”).

      Press Save to exit the lightbox and you are done.

      For further assistance, don’t hesitate to contact our Support Team at or via our contact form.


  9. Hi, We have a contact form that we have set up for our field team, and i need to get the first letter of certain fields capitalised, however the data to be entered can be of variable lengths so i cannot use a standard custom field validation method as it would force the exact amount of characters to be entered.

    All i need is for the first letter to be a capital, but then for it to allow a variable amount of text afterwards such as the first entry being John and the next being Timothy etc.

    Can anyone help please?


    1. Hello Mark!

      You can check the Capitalize First Letter feature of the Name field. The field is located in the Advanced tab of the Add Field panel, while the option is displayed below Options.

      For further assistance, don’t hesitate to contact our Support Team at or via our contact form.


  10. I have created a quote page on my website, and utilized your 123formbuilder. There is a field called Food Budget for this Event. I want to know how I can allow users to enter a comma, dollar sign, and period in this field i.e. $1,000.00

    1. Hello!

      You may use the Price field to achieve what you are looking for. It comes with the dollar sign in front of the input box and the form users may add decimals.

      For further assistance, don’t hesitate to contact our Support Team at or via our contact form.


  11. I want to have my visitors enter their web address but I do not want the validation to fail because of the missing “http://” how do I achieve that?

    1. Hello Simon!

      You could add a textbox field to your form, set it on URL for the validation and type in the text “http://” inside the Default Value box. Whenever the form visitors access your form, they can click on the input of the field and complete it with their website.

      For further assistance, don’t hesitate to contact our Support Team at or via our contact form.


  12. How can I use custom validation to enforce a negative number. For example I want a user to input -100. If they enter “100”, it should not allow it.

    1. Hello!

      We do not support custom validation for negative numbers only, but what you can do is use field rules and hide the submit the button if the input is bigger than -1. You can also use field instructions to inform your form visitors that only negative numbers are permitted in the field. Here are the steps:

      1. In My Forms, select your form and go to Settings.

      2. In Settings, go to RulesField Rules.

      3. Hit Add Rule and set this condition: If name of your field is greater than -1 then hide Submit Button.

      How does this work: if the person who fills out the form types in the field the value 0, for example, the submit button will disappear and the form can not be submitted. But if the person types in -1, the submit button will reappear. The same for -2, the submit button will still be present. But if the person types in 1, 2 or 100, the submit button will disappear again.

      In the Form Editor you can add Instructions to your field, to inform your form users of the input required in the field.

      For further assistance, don’t hesitate to contact our Support Team at or via our contact form.


    1. Hello!

      We haven’t got the option to automatically change form inputs in Uppercase. You can, however, use a JavaScript code that contains this functionality and link it to your form. If you upgrade to the Platinum plan, you can use the WebHooks integration that applies these changes on your server through a script. The script and server, however, are provided by you.

      Our available plans:

      What you can do to prevent form users from adding form inputs in Lowercase is to add a custom field validation to your textboxes. Select custom under field validation and add the value U. Form users will not be able to submit the form unless they type their input in Uppercase. If you upgrade to Gold, you can use Translations to change the system message from Expected input: custom to any text you want, such as Expected input: Uppercase letters.

      For more questions or assistance, please contact our Support Team at and they will gladly help.


    1. Hello!

      To change error messages on your form, simply go to the Form SettingsTranslations section, add a default language (e.g. english) and hit Customize (hover mouse over the line to see the button). In the lightbox, go to System Messages to translate/change error messages that your form users might see. You don’t need to enable translations on your form. Read more here.

      For questions or assistance, don’t hesitate to contact our Support Team at


  13. I want to change the input value of a date to month/year but I can’t fine the ‘custom validation’ drop down menu on my forms? Where so I find it? Thanks, John

    1. Hello John!

      To change the input value to month/year , you’ll need to add a Textbox field to your form, instead of the Date field. Drag and drop the Textbox on your form and go to Field Validation from the Edit Field panel. Once there, select date-MMYYYY from the dropdown list. Remember to include a field instruction for your form visitors to add ‘/’ between the month and the year, otherwise they will not be able to submit the form.

      For more questions or assistance, please don’t hesitate to contact our support specialists at


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