Harvest is a time-tracking-first tool that grew invoicing on top. Influx Theory is invoicing-first with no time-tracking opinion. If your team lives in time entries, Harvest is the system of record. If your team lives in deliverables, Influx Theory gets out of the way.
Pick Harvest if billable hours are your primary unit of work. Pick Influx Theory if you bill milestones, retainers, or fixed fees.
| Feature | Influx Theory | Harvest |
|---|---|---|
| Time tracking | Not included | Core feature |
| Invoicing speed | 30 seconds | Several minutes (pulls from timers) |
| Retainer billing | Built-in | Manual workaround |
| Milestone billing | Built-in | Manual workaround |
| Card payments | Stripe (2.9% + 30¢) | Stripe / PayPal |
| Starting price (seat 1) | $19/mo | $13.75/mo per seat |
| Team pricing | $49/mo team plan | $13.75/mo per seat (scales linearly) |
Agencies and consultants who bill by deliverable, milestone, or retainer.
Teams whose primary billing unit is the tracked hour.
No credit card required. $19/mo after, unlimited everything.
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