Well, how are they breaking in? Are they using a password or a script exploit. Check the access logs for the site to see what they are doing. Sounds like it may be password sniffing or malware - do you always access with a secure URL?
WHMCS is a well built billing system which has a very good security compared to other billing scripts. So I can't recommend you another beyond WHMCS.
I am wondering how these hackers get in?
Probably you haven't tweaked WHMCS to avoid hackers. Also this may happen if you have an outdated version of WHMCS.
If neither of my suggestions are working for you, contact WHMCS support and describe your situation. Maybe they can help you.
But, Ah!
There is one another billing system which can be compared to WHMCS. It's name is ClientExec. You can give it a try if you decided not to be with WHMCS anymore.
for a start, SSL is needed when dealing with personal infomation.
You can get ssl's cheap from various domain providers... I like namecheap myself but most places have them for around $10~
Hi,
To increase your whmcs security rename your whmcs admin folder, then re-issue your license and use ssl.
Did you try renaming your admin folder? The new WHMCS allows you to rename the admin folder.
I believe you need to use another pass only to be able to access there with more security.Lately, I've been having a lot of people breaking into my WHMCS. I know its not my server security, because they would have locked me out of my server.
I believe you need to use another pass only to be able to access there with more security.