A Common Method is to Limit the use of the Application until a Registration Code has been Entered, this can be an Algorithm which easily generates a code using Personal Data of the User, ie.
Name, Phone No., Email, etc..

So when they register you generate the Key, send it to them, they enter their details in the Registration Form which uses it to Generate the Same Code you sent, they then Enter the Code you sent them, they match and the System is registered.


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Aaron Young
Analyst Programmer
[email protected]
[email protected]