Freelance Billing Guide: Hourly Rates, Invoicing & Tools

Why most freelancers leave money on the table

Three problems show up again and again when I talk to other freelancers about billing:

• Forgetting to track time. You do the work, you move on, and at invoice time you reconstruct hours from memory. Most people underreport by 20-30% this way. That gap comes straight out of your take-home pay.
• Undercharging. A lot of freelancers pick a rate by looking at what competitors charge and going slightly lower. That's a race to the bottom. The right starting point is your own cost floor: what you need to earn to cover expenses and pay yourself a real salary.
• Late invoices. Sending an invoice two weeks after the work is done signals to the client that payment isn't urgent. It also pushes your cash flow out by another two weeks on top of whatever payment terms you agreed to.

None of these are hard to fix. They just require a system. The three sections below are that system.

Three pillars of a billing system that works

A billing system has three moving parts. Get all three right and billing becomes a 30-minute-per-week task instead of a source of anxiety.

• Your rate. The number you charge per hour has to be grounded in real math, not guesswork. Too low and you're subsidizing your clients. Too high without justification and you lose work you could have won.
• Your invoicing process. When you send, what you include, and what payment terms you set all affect how quickly money arrives in your account.
• Your tools. The software you use to track time and generate invoices should cost less than the time it saves you. That calculation is less obvious than it looks, especially with "free" tools.

Each pillar gets its own deep-dive below. Read them in order if you're starting from scratch, or jump to whichever one is your current weak point.

1. Your hourly rate: the foundation

Most freelancers set their rate by anchoring to what they earned as an employee or what they see competitors charging. Both approaches miss the same thing: your actual cost structure as a self-employed person is different from an employee's.

As a freelancer you pay both sides of social contributions, you cover your own equipment and software, you have unpaid vacation and sick days, and you spend a chunk of your working hours on non-billable admin. A rate that looks competitive might still leave you earning less than minimum wage once you account for all of that.

The right approach is to start from your income floor: the minimum you need to earn after expenses to pay yourself a livable salary. Then divide by your realistic billable hours per year (not your total working hours). That gives you a floor rate. From there you add a margin for profit, growth, and the fact that not every client engagement will be perfectly efficient.

The deep-dive guide walks through the full formula with a worked example and an interactive calculator: How to set your freelance hourly rate →

2. Invoicing that actually gets paid

The invoice itself matters less than the habits around it. Two habits make the biggest difference: send fast and set short terms.

Send within 24 hours of completing work or at the end of the project. Waiting longer trains clients to treat your invoices as low priority. It also means you're carrying the cost of completed work for longer before you see any cash.

On payment terms: Net-7 or Net-14 is the right default for most freelance clients. Net-30 is only appropriate for large enterprise clients where it's contractually required. Every extra day of payment terms is a day you're effectively lending money to your client at zero interest.

Beyond timing, the content of the invoice matters too. A clear description of what was delivered, an itemized breakdown of hours, and a professional layout all reduce the chance of a client coming back with questions that delay payment. Teetrack generates invoices directly from tracked time, so the hours on the invoice match the hours in the timesheet exactly.

The full invoicing guide covers what to include, how to handle late payments, and how to structure recurring invoices: How to invoice as a freelancer →

3. The true cost of free tools

Free time-tracking tools are genuinely fine for some situations. If you have one or two clients, no invoicing needs, and you just want a basic log of hours, a free tool does the job.

The problem is that most freelancers outgrow that situation quickly. As soon as you need invoicing, project budgets, client reports, or integrations with your calendar, free tools start adding paid add-ons. Those add-ons stack up. The total cost of ownership of a "free" tool with three paid add-ons often exceeds the cost of a paid all-in-one tool.

There's also a time cost. Switching between a free tracker and a separate invoicing tool and a separate reporting tool takes time every week. That time has a dollar value. If you bill at €60/hour and the fragmented workflow costs you two hours a month, that's €120/month in opportunity cost, not counting the subscription fees.

The TCO comparison guide runs the actual numbers across several popular free and paid tools: Free vs paid time trackers: the TCO math →

What I use today

Full disclosure: I built Teetrack. So take this section with that in mind.

My workflow is: start a timer when I begin a task, stop it when I finish, then at the end of the week review the timesheet and generate an invoice. The whole thing takes about 20 minutes on Friday afternoon. Teetrack handles the timer, the timesheet, and the invoice in one place. It syncs with my Google Calendar so meetings show up automatically. It's hosted on Hetzner in the EU, which matters to me for data residency.

I'm not claiming it's the only tool that works. But it's the one I built because I couldn't find something that did all three steps without friction. If that sounds like your situation, the pricing page has the details.

Related guides

If you run an agency rather than billing solo, the next guide covers what's different: utilization, capacity planning, and client reporting. Agency time tracking guide →

Start here

If you're new to freelance billing, start with the hourly rate guide. Getting that number right is the foundation everything else builds on. Then read the invoicing guide to tighten up your process. Then, once you're billing consistently, revisit your tools and run the TCO math.

If you want to try Teetrack, there's a free tier with no time limit. No credit card required. See what's included →