Common Financial Model Mistakes That Kill Investor Interest

Investors often spend only a few minutes on a financial model before deciding whether to dig deeper. These are the mistakes that make them stop.

1. The hockey stick with no explanation

Growth jumps from 5% to 25% a month the moment funding arrives. Unless you can explain exactly what drives the jump, it reads as wishful thinking.

2. CAC that stays flat forever

Scaling ad spend almost always pushes CAC up. A flat CAC assumption is one of the first things investors question.

3. Blended margins that hide channel differences

Website, marketplace, and quick commerce sales have very different economics. A single blended margin hides where you make and lose money.

4. Ignoring working capital

This is one of the most damaging mistakes, because the P&L can look healthy while cash disappears.

Numbers in this example are illustrative.

A brand grows from ₹20 lakh to ₹60 lakh monthly revenue. Product cost is 35% of revenue, and it holds about 60 days (two months) of inventory.

• Inventory at ₹20 lakh revenue: ₹7 lakh monthly cost × 2 = ₹14 lakh
• Inventory at ₹60 lakh revenue: ₹21 lakh monthly cost × 2 = ₹42 lakh
• Extra cash locked in inventory: ₹28 lakh, which never appears on the P&L

5. Missing variable costs

Payment gateway fees, returns, RTO, packaging, and marketplace fees are often left out or underestimated.

6. Statements that don’t connect

If your P&L, balance sheet, and cash flow statement aren’t linked, your cash projections can’t be trusted.

7. Hard-coded numbers everywhere

Investors want to change an assumption and see the whole model update. Hard-coded numbers make that impossible.

8. No scenarios

A single optimistic case suggests you haven’t thought about what could go wrong. Include base, conservative, and optimistic cases.

9. Team costs that arrive too late

Revenue triples but headcount stays flat. Investors know growth needs people.

10. An ask that doesn’t match the model

If the model shows you need ₹4 crore but you’re raising ₹2 crore, investors will ask what happens after the money runs out.

A quick self-check

• Can you explain every key assumption in one sentence?
• Does CAC rise as spend increases?
• Is margin shown by channel?
• Does the model show cash, not just profit?
• Does your funding ask match your lowest cash point plus a buffer?

FAQs

How long should it take to build a proper financial model?

Typically one to three weeks, depending on how organised your historical data is.

Should I use Excel or Google Sheets?

Either works. What matters is clear structure, linked statements, and visible assumptions.

How often should I update my model?

At least monthly, comparing actual results against projections.