In the application I need to check the form field for German phone numbers, tried some, but it doesn’t work for sure, any help would be appreciated.
The answers to this question should solve this for you: Verify your phone number using JavaScript
You just need to adjust the regex to match the German format
A regular expression from https://github.com/posabsolute/jQuery-Validation-Engine/issues/265 can do the job: / ^ ([+] [0-9] {1,3} [.-])? ([(] {1} [0-9] {1,6} [)])? ([0-9. - /] {3,20}) ((x | ext | extension) []? [0-9] {1,4})? $ /