Managing startup finances: avoid the cash traps that kill companies

Executive overview

Most startups die because they run out of cash — and most founders don't see it coming. Three numbers tell you everything: bank balance, money in, money out. From these you can calculate burn, runway, growth rate, and whether your company is default alive or default dead.

Hiring and scaling decisions are the second layer of danger. Every employee costs more than their salary, and headcount is not a proxy for success.

The founders who survive treat runway as a survival metric, not a vanity number — and always assume the current funding is their last.

The three numbers every founder must know

• Burn = expenses minus revenue (read directly from your bank statements)
• Runway = bank balance divided by average monthly burn; gives months until you run out of money
• Growth rate = (month 2 revenue − month 1 revenue) / month 1 revenue
• Use Trevor Blackwell's default alive calculator to model whether constant expenses and current growth rate reach profitability before cash runs out
• If you need more capital than you have to reach profitability, you must cut expenses or accelerate revenue growth

Check your numbers weekly, not monthly

• Review bank balance, burn, and runway at least weekly
• If runway is short or trends are inconsistent, check daily
• Know your numbers on demand — not just when someone asks in a meeting
• Don't massage numbers to feel better; you run out of money on the same day regardless

Expenses will increase — account for it

• Early-stage CAC is artificially low: first users are self-motivated; acquisition gets harder and more expensive over time
• Founders doing everything at minimum wage understate true labour cost; as you hire, that cost surfaces
• Every hire costs 25–50% more than their base salary (equipment, desk, health insurance)
• A $100k engineer costs $125k–$150k all-in
• Model the worst case: if runway holds at 8 months under pessimistic assumptions, 10 months in reality is a bonus

Outsourcing responsibility without staying informed

• Hiring a bookkeeper is correct once finances get complex — but the CEO retains full responsibility for the numbers
• Bookkeepers work from bank statements and make their best guesses; they will sometimes be wrong
• Read every monthly report; question anything that looks off — this is how errors get caught before they become crises
• Founders who ignore monthly reports and then blame the bookkeeper are the ones who run out of runway without warning

Hiring too fast and scaling before product-market fit

• Headcount is not a measure of success; revenue per employee is
• Every hire is an investment — measure its return; a salesperson who costs more than they bring in is a losing bet
• Be prepared to fire fast if someone is not pulling their weight
• Competing with well-funded startups on headcount is a trap; the best companies do more with less
• Before product-market fit, spend as little as possible — more developers or salespeople will not get you there faster
• If sales are low because you lack salespeople, that is not a product-market fit problem; it is a product problem
• When you have product-market fit, even a rough V0 has customers beating a path to your door

Letting runway get too low before raising

• Always assume the current raise is your last; plan a path to profitability on existing capital
• Start thinking about raising at 12 months of runway — not 6
• A raise can take 3 months to close; at 6 months of runway you are losing leverage daily as cash falls
• If you reach 6 months and a raise fails, there is almost no time left to pivot to profitability
• Investors at seed stage do not expect detailed forecasts — they want to understand market size and the hypothesis
• Series A investors do expect a plan, because you should have product-market fit by then

CFO, bookkeeper, and CPA — who you need and when

• Bookkeeper: needed once you raise; turns bank transactions into balance sheets and income statements
• CPA: needed annually to prepare and file tax returns
• Consulting CFO: available post-Series A for forecasting, budgets, and fundraising support
• Full-time CFO comes surprisingly late — often not needed until well after Series A
• Before all of these, the founders must do it themselves and stay close to the numbers throughout