How good idea do you think is using other method for billing that is not whmcs ,lets say any cart be free or not license but......................
administering all client hosting accounts just with a booklet and a pen?

WHMCS has been a very good system to serve our clients so far. But if you describe the system that you suggest better, it will be easier to pretend the new system.

Good luck with that booklet and pen !!

Depends on how many customers you have. When we were doing design projects for customers we often used an Excel sheet to track how many hours of work we had done etc, but we're talking less than a dozen projects per month.

If you're dealing with multiple clients and those clients are paying monthly or quarterly, do yourself a favor, sped the $15/month for the WHMCS Lease and get it done right. Your clients will appreciate a professional experience also. It's not always about YOU and YOUR busienss - often times things are implemented because it's what your client wants/needs/likes.

You can purchase cheapest Billing license from Licensepal.

or If you want to use Free Billing then at least you need to pay $10 or $25 and you can get cheaper billing license.

Free License:
1. THT(new version of cP Creator - maybe I am wrong)
2. phpcoin

Best For you: Account Lab Plus