The Tax Line Your Model Left at Zero

February. The books for the prior year had closed the week before. Then the accountant called with a number nobody had put in the model. At one company I sat with, the bill was $212,000 in taxes, due in seventy days, against roughly $900,000 in the bank.

The bill was a mix: state franchise taxes, sales tax in three states the company had crossed nexus thresholds in, and a small federal liability from a one-time gain. None of it was in the financial model. The founder had built the model on one assumption: the company pays taxes only when it turns a profit.

The company was not profitable, so the tax line had been left at zero. That is the trap. Founders read "no federal taxable income" as "no taxes," and the reading is wrong in three predictable ways.

Franchise tax comes due regardless of profit. Delaware, Texas, and California all levy annual fees tied to revenue or capitalization. Sales tax is money the company already collected from customers and owes back to the state. State income tax follows your employees: hire a remote engineer in a new state, and you have a filing obligation there, wherever you are incorporated. Each piece can look small. Together they are real money.

A model without those lines reports a runway that is too long. In cash terms the company is running shorter than the spreadsheet claims. The gap is small in year one, wider in year two, and material by year three, especially once revenue spreads across states. Meanwhile the founder keeps hiring and spending against the wrong number. It surfaces at filing, the worst possible moment, because a tax bill has a hard due date and almost no negotiating room. This is the same failure as a runway that lied by six months: the cash was never as long as the model said.

The discipline is boring and it works. Put a tax line in the model from day one. Start it near zero. Grow it as you cross nexus thresholds, add employees in new states, and push up the franchise base. Update it every year with a tax professional who is looking hard at your exposure, not merely filing the return.

The international version is worse by an order of magnitude. Open an entity in another country, for hiring or for sales, and you inherit its corporate income tax, withholding on intercompany payments, transfer-pricing rules, and reporting to two governments at once. The complexity does not add. It multiplies.

Hire the advisor before the first surprise, not after. At an early-stage company the relationship runs a few thousand dollars a year and buys a large amount of risk reduction. The advisor's job is not to file returns. Its job is to flag the exposure while you can still plan around it. If you have ever spent deferred revenue you never truly had, you already know how a cash surprise lands.

Build the tax line. Update it every quarter. Hire the advisor. The bill is already on its way, whether or not it shows up in your model.