enable tax by customer request

Paper Invoices Module For WHMCS 1. Introduction The aim of the project is to extend the default WHMCS tax functionality. 2. Workflow 1. Customers register in the system (in cart and in standard registration form) 2. During registration, customer can choose to have "Paper Invoice" (checkbox field) that will display additional fields in the form: Official name Financial ID National ID Registration ID Postal Code Invoicing Address 3. Customer can also change their details (Edit Account) to enable "Paper Invoice" and additional fields (as above) will become available. 4. If customer has "Paper Invoice" enabled, every NEXT invoice of the customer will have tax added accordingly to the Tax Settings 5. In a case that customer enables/disables "Paper Invoice" setting, the module will modify UNPAID invoices with the tax accordingly. 6. Admnistrator will have a simple addon "Paper Invoices" where he can: See the list of invoices to be sent (Not Sent list with datatables paging and fast filtering) Mark invoice as Sent See the list of invoices that were sent (Sent list with datatables paging and fast filtering) Mark invoice as Not Sent 7. In a case that customer enables/disables "Paper Invoice" setting, the module will add/remove invoices from the Paper Invoices addon: All unpaid invoices of the customer Paid invoices of the customer, that were paid no more than 10 days ago 8. In a case that client has tax enabled, the module will NOT modify tax on the invoice (may be needed when client needs a tax but don't want to have paper invoice). Additional Notes: 1. Client need to set up Tax Rules in the WHMCS system properly to charge tax on the invoices. 2. Using Custom Client Filed will let administrator to easily manage settings related to Paper Invoice and no additional improvement is required in profile management section. 3. By default, every client in the WHMCS system will need to have tax disabled. Module will automatically add tax to the invoice, it will not enable/disable tax of the client. 4. Quotation includes only one order form modification. In a case that Client uses more than one order form in their WHMCS instance, additional order forms modifications will have to be quoted additionally. Integration Contents 1. Modifications of registration form 1. One order form modification 2. General registration form modification 2. Automatic tax configuration for clients that do not have tax enabled in their account 1. Adding/Removing tax based on Tax Rules for already created unpaid invoices 2. Adding/Removing tax based on Tax Rules for new invoices (WHMCS hook) 3. Addon Module for Administration 1. Not Sent Invoices List with filtering and paging + option to "Mark Invoice as Sent" 2. Sent Invoices List with filtering and paging + option to "Mark Invoice as Not Sent" 3. Adding/Removing to the Not Sent invoices list for already created unpaid invoices and paid invoices with date paid less than 10 days 4. Adding/Removing to the Not Sent invoices list for new invoices and paid invoices with date paid less than 10 days (WHMCS hook)