Across all four tools, the invoice itself is still the weak link. Hours get logged well, but the invoice gets built somewhere else.
Media agencies bill on two clocks at once. There's the retainer hours a team logs against strategy and reporting, and there's the campaign cycle — flighting, creative briefs, performance reviews — that doesn't care what week it is.
Most time tracking tools were built around one steady project, not a rotating set of campaigns with different platform access, different attribution windows, and different billing dates. That's exactly where campaign hours never reach the bill.
A handful of AI-powered options handle that better than the rest. Here's an honest read on which.
What Actually Matters for Campaign-Based Billing
Reporting depth, more than anything else. A media agency needs billable hours filterable by client, by campaign, and by date range — pulled in under two minutes, without reformatting before a client sees it.
If generating that report takes longer, the tool is adding friction to a billing cycle that's already running on tight platform deadlines. It's usually where margin quietly follows the missing hours out the door.
Toggl Track — Best for Agencies Running Several Campaigns at Once
Toggl connects to 100+ tools, including the project and ad-platform stack most media teams already run — Asana, Trello, Monday.com, Slack, and the major accounting platforms. Smart Suggestions draft entries based on past behaviour and flag timesheet gaps before submission.
There's no native invoicing in the core product, and no payroll integration. For an agency juggling several active campaigns with different reporting cadences, Toggl's per-project filtering is strong enough to be worth the missing invoicing layer.
Harvest — Best for Agencies That Want the Full Track-to-Invoice Loop
Harvest pairs time tracking with built-in invoicing, online payments, and budget alerts tied to each project. For campaign work with a fixed media budget, those alerts flag overservicing before a creative brief quietly runs over scope.
The AI features here are thinner than newer entrants offer — there's no automatic capture, so accuracy depends on the team's timer habits. Recent price increases are worth checking against your seat count before renewal.
Timely — Best for Account Teams Who Forget to Log Time Between Calls
Timely's Memory app records activity in the background across the apps and platforms an account team uses, then drafts a timesheet AI suggests and the team approves. For account managers bouncing between client calls and platform dashboards all day, that removes the timer-button friction that kills most tracking habits.
It's premium-priced, and the AI suggestions need a few weeks of data before they're reliably accurate. There's no native invoicing — Timely sits upstream of billing, not inside it.
TimeCamp — Best for Agencies Wanting One Tool That Does Everything
TimeCamp's AI layer covers attendance, billing rates, approvals, and budget tracking in one configurable product. The breadth is genuinely useful for agencies managing several account teams and approval chains at once.
That breadth also means setup overhead. Smaller account teams who just want tracking to work without configuring keyword mapping may find it more tool than they need.
The Honest Verdict
Harvest comes closest to a real track-to-invoice loop. Toggl and Timely both need a second tool for billing, and TimeCamp asks for setup time most agencies under twenty people don't have spare.
Across all four, the invoice itself is still the weak link. Hours get logged well, but the invoice gets built somewhere else. Whether a client actually paid it tends to live in a payment tracking spreadsheet nobody reviews until cash flow gets tight. That's the exact gap covered in how to track invoices so you never chase the same client twice.
Agency OS is built for exactly that handoff. The invoice tracker shows every invoice by status — draft, sent, due, overdue, paid — linked directly to the client and campaign record. Overdue filtering surfaces what's stuck before it becomes next month's cash flow surprise.
Pick the time tracker that matches your campaign cadence first. Then run the resulting invoices through a real invoice management system, not payment tracking software bolted on after the fact.
