What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
Based on what you have mentioned, I believe that you are looking for the mask property to accept only 8 numbers in a field, no more and no less.
I would however like to confirm this from you if possible and if so we would be happy to assist you in setting it all up.
It would also be useful if you can give us a link to your jotform to see which fields you are using.
sorry instead of number of 8 to number of 7
You can click on the field in question, and set the Input Mask on it. Make sure to click on the 'Fill Mask Validation', so it will ask for the exact amount of symbols.