Hi everyone ,
I'm co-founder of Hostingwalk & PayRequest.
And I wrote a blog about how customers can pay WHMCS invoices without having to log in:
https://medium.com/payrequest/let-your-whmcs-customers-pay-via-mail-without-the-need-to-login-b3a750bf0673
There are many reasons why customers do not pay the invoices you send via WHMCS:
They see no payment option in your e-mail.
They do not know their login details (e-mail, password)
They think it costs too much time to log in, and plan to pay later (and then forgot it).
With WHMCS Payment Links powered by PayRequest, you can put a unique payment link in your e-mails that redirect the customer directly to your Payment Page with the exact amount they need to pay & their invoice number.
Please tell us if you like it, and feedback is always welcome!