I do freelance work periodically. Often, a company's accounting dept has a standard form they like you to use (usually a spreadsheet template) for documenting time, but in this case it sounds like not. When there is a standard template, I track time in toggl (https://www.toggl.com
) and then copy over my entries to the spreadsheet. When there is no standard form, I use Billings (http://www.marketcircle.com/billings
), a really slick time tracking and invoice generation app for Mac. I went with Billings primarily because it is "pay once" and I'm not constantly doing freelance work so did not want to be bound to a monthly subscription for software that might go unused for several months at a time, plus the PDF invoices it generates are very professional-looking. If you must go with a purely online SaaS solution, I'd suggest starting with toggl as it does have invoicing functionality, is very widely used, and the free plan has a lot of functionality (and the paid plans are cheap compared to others). If it doesn't suit your needs, I've heard good things anecdotally about Freckle (http://letsfreckle.com
), so might want to check that out, and also FreshBooks (http://freshbooks.com
) and Xero (http://xero.com
) -- it's a pretty saturated market but I believe I hit the big ones. For my own needs, I like toggl and Billings.