Since I started my first web hosting company I have used Namesilo domain registrar.
There are few reasons:
I didn’t had much budget to afford any other company.
I needed API, which I got for free
And I needed to pay as i go (not to deposit 100$)
The most important, they have WHMCS plugin! They support HostBill and BoxBilling too.
.com domain are low as 8.99$!
Check them out and let me know what you think!
Do not forget to use promo code for 1$ discount:
Another promo codes: