Billings 1.x should be a public beta and it is a damned cheek to charge for it.

Not only can it not even add up correctly, the results are unacceptable for almost any jurisdiction that operates VAT/TVA taxes and the reports (principally the Invoice) is hopeless.

Apple's site lists a number of applications that support time and expenses charging for different markets and almost every single one is better than Billings.

Avoid.