If you're guessing how many hours you worked last week, you're almost certainly leaving money on the table.
There's a specific kind of dread that hits freelancers at the end of the month. You know you worked on Client A's project — you remember the late nights, the Slack threads, the revision rounds — but when you sit down to invoice, the actual hours are a blur. Was that research session on Tuesday 90 minutes or two and a half hours? Did you bill for the phone call on Thursday?
If this sounds familiar, you're not alone. Most freelancers start out tracking time in the worst possible way: from memory, after the fact, in a spreadsheet that grows more unreliable by the week.
The fix isn't complicated. But it does require a shift from "I'll figure it out later" to "I'll track it now." Here's how to set up a billable hours workflow that's accurate, painless, and directly connected to getting paid.
Why Accurate Time Tracking Matters More Than You Think
Let's start with the math. If you bill $75 an hour and you under-report by just 30 minutes a day, five days a week, that's 2.5 hours per week you're not billing for. Over a year, that's 130 hours — or $9,750 — left on the table. Not because you didn't do the work, but because you didn't write it down.
Under-tracking is the default for freelancers who rely on memory. Research consistently shows that people overestimate how well they recall how they spent their time. The longer the gap between doing the work and logging it, the more hours evaporate.
Beyond the revenue impact, accurate time tracking gives you data you can actually use. Which clients take more time than they're worth? Which types of projects are most profitable? Are you spending 20% of your week on admin tasks you're not billing for? You can't answer these questions without reliable time records.
The Two Approaches: Timers vs. Manual Entry
There are fundamentally two ways to track billable hours, and both have their place.
Real-time timers. You start a timer when you begin working on a task and stop it when you're done. This is the most accurate method because there's no recall involved — the clock captures exactly how long you worked. The downside is remembering to start and stop the timer, especially when you're switching between tasks frequently or get interrupted.
Manual time entry. You log your hours after the fact — at the end of a work session, at the end of the day, or (less ideally) at the end of the week. This is more flexible and works better for people who find timers disruptive to their flow. The trade-off is accuracy: the longer you wait, the less precise your entries become.
The best approach for most freelancers is a hybrid. Use timers for focused work sessions where you're heads-down on a single client's project. Use manual entry for quick tasks, phone calls, and anything you forgot to time. The key is logging everything the same day it happens.
byllr supports both approaches. You can start and stop timers directly from the dashboard — one click to start tracking against a specific client and project, one click to stop. Or you can manually add time entries with a date, duration, and description. Either way, every entry is tied to a client and project, so when it's time to invoice, you're not hunting through a spreadsheet trying to figure out who to bill for what.
What to Track (and What Not To)
Not every minute of your day is billable, and that's fine. The goal isn't to account for every second — it's to capture every hour that should show up on an invoice.
Always track:
- Active project work (design, development, writing, consulting, etc.)
- Client meetings and calls
- Email communication that's substantive (not a quick "sounds good" reply, but a 30-minute email with detailed feedback or strategy)
- Research and preparation directly related to a client's project
- Revisions and edits requested by the client
- Travel time, if your contract specifies it's billable
Generally don't track (as billable):
- General business admin (bookkeeping, invoicing, marketing yourself)
- Learning new skills, unless the client specifically asked you to learn something for their project
- Networking and business development
- Internal tool setup and workflow optimization
That said, tracking your non-billable time is still valuable — just keep it in a separate category. Understanding how much time goes to admin versus client work helps you price your services more accurately and identify where you're losing productive hours.
In byllr, you can create separate projects for internal work (like "Admin" or "Business Development") under your own name as a client. These entries won't end up on any client invoice, but they'll show up in your reports so you can see the full picture of where your time goes.
Setting Up a System That Sticks
The reason most freelancers fail at time tracking isn't that they don't know they should do it — it's that their system is too annoying to maintain. Here's how to build one that actually sticks.
Reduce friction to near zero. If tracking time requires opening a spreadsheet, finding the right tab, scrolling to today's date, and manually typing in a formula, you won't do it consistently. Your tracking tool should be open and accessible whenever you're working. One click to start, one click to stop.
Track in real time, not in arrears. The single biggest improvement most freelancers can make is shifting from end-of-week logging to same-day logging. It doesn't have to be a running timer for every task — even a quick manual entry at the end of each work session is dramatically better than reconstructing your week on Friday afternoon.
Use client and project categories from day one. Don't dump everything into a single time log and sort it out later. Every entry should be tagged with a client and a project at the time you create it. This makes invoicing trivial — you just filter by client and date range, and your invoice line items are ready.
Write brief descriptions. "Website work" means nothing three weeks later. "Homepage hero section — responsive layout and image optimization" takes five extra seconds to type and saves you from guessing what you did when the client asks. Your future self (and your client's accounts payable department) will thank you.
Review weekly. Set aside 10 minutes every Friday to scan your time entries for the week. Look for gaps, vague descriptions, or entries that seem too short. This weekly review is your safety net — it catches mistakes while they're still fresh enough to fix.
From Time Entries to Invoice: Closing the Loop
Here's where accurate time tracking pays off — literally.
If your time entries are clean, categorized by client and project, and include clear descriptions, generating an invoice should take minutes, not hours. The invoicing step should be a formality, not a research project.
This is where most spreadsheet-based systems break down. You end up copying and pasting rows from your time tracker into an invoice template, manually recalculating totals, and hoping you didn't miss anything. It's tedious, error-prone, and it's one of the main reasons freelancers procrastinate on invoicing — which means they get paid later.
With byllr, this loop is closed by design. Your time entries and expenses live alongside your clients and projects. When you're ready to invoice, you select the client, choose the time entries and expenses to include, pick one of five professional invoice templates, and generate a PDF. The rates, descriptions, hours, and totals are already calculated. You review, send, and move on.
The time tracking isn't a separate activity from invoicing — it's the first step of invoicing. Every timer you start, every entry you log, is building the invoice you'll send at the end of the month. When you think about it that way, tracking becomes a lot easier to stay on top of.
Common Time Tracking Mistakes
Batching your entries at the end of the week. This is the most common mistake and the most expensive one. Even a two-day gap introduces significant inaccuracy. Track daily at minimum.
Not tracking small tasks. The 15-minute phone call, the quick email review, the "can you just take a look at this" request. These add up to hours per week that many freelancers never bill for. If it's work for a client, it's billable (unless your contract says otherwise).
Using a tool that's separate from your invoicing. If your time tracker doesn't connect to your invoicing workflow, you're creating manual steps that introduce errors and add friction. The fewer systems you need to move data between, the more accurate and efficient the process becomes.
Rounding too generously in the client's favor. There's nothing wrong with rounding to the nearest 15 minutes, but make sure you're not always rounding down. If you consistently turn 22-minute tasks into 15-minute entries, you're giving away real money over time.
Not tracking at all because you bill flat rates. Even if you bill per project rather than per hour, tracking your time tells you whether your flat rates are actually profitable. If you quoted $2,000 for a project and it took 40 hours, your effective rate is $50/hour. If you didn't track the time, you'd never know — and you might keep quoting $2,000 for projects that consistently take longer than you expect.
The Bottom Line
Tracking billable hours isn't glamorous, but it's the foundation of getting paid accurately and on time. The best system is one that's fast to use, connected to your invoicing workflow, and reviewed regularly.
If you're currently relying on memory, spreadsheets, or a tool that makes time tracking feel like a chore, byllr was built to make it painless. Start a timer with one click, log entries against specific clients and projects, and turn your tracked time into professional invoices in seconds. The free plan gives you enough to try the full workflow — no credit card required.