Every US small business owes some combination of federal income tax, self-employment or payroll taxes, and state and local taxes, and most owners must also pay federal estimated taxes quarterly rather than once a year. The exact mix depends on your entity type: a sole proprietor reports business income on a personal return and pays self-employment tax, an S-corp passes profit through to owners but must run reasonable owner payroll, and a C-corp pays corporate income tax on its own return. On top of income tax, if you have employees you owe payroll tax deposits (income withholding plus Social Security and Medicare), and if you sell taxable goods or services you likely owe sales tax collected from customers and remitted to the state. The obligations are predictable; the trouble is almost always timing, because tax due dates rarely line up with when revenue actually lands in the bank.
Key takeaways
- Most US small businesses must pay federal income tax, self-employment or payroll taxes, and state and local taxes — the exact mix depends on entity type.
- Federal estimated taxes are due four times a year (roughly April, June, September, and the following January), not just at filing.
- Payroll withholding and sales tax are trust-fund taxes; misusing them can create personal liability through the trust-fund recovery penalty.
- S-corp owners must run reasonable-salary payroll, but distributions above that salary avoid self-employment tax.
- Since the 2018 Wayfair decision, remote sellers can owe sales tax in states where they have no physical presence.
- Revenue-based advances underwrite on bank deposits and revenue, with FICO around 500+, minimums near $10,000, and funding in 24-48 hours — never guaranteed.
- Borrowing to pay taxes makes sense for a seasonal timing gap, not for a chronic or structurally declining shortfall.
The Core Federal Taxes Every Business Faces
Federal obligations fall into a few buckets that apply in different combinations depending on how you're organized:
- Income tax. Sole proprietors, partnerships, and S-corps are pass-through entities, so business profit flows to the owners' personal returns and is taxed at individual rates. C-corporations pay a flat corporate income tax at the entity level, and shareholders are taxed again on dividends.
- Self-employment tax. If you're a sole proprietor or partner, you pay both the employer and employee halves of Social Security and Medicare on your net earnings. This is the tax that surprises first-year owners most, because it stacks on top of income tax.
- Payroll (employment) taxes. The moment you have a W-2 employee, or pay yourself a salary through an S-corp, you must withhold income tax and FICA, add the employer match, and deposit those funds on a schedule the IRS assigns you.
- Excise taxes. Narrower, but real for fuel, transportation, certain manufacturing, and a handful of other industries.
The underwriter's read on this: income tax is a once-or-quarterly event you can plan for, but payroll deposits are the unforgiving one. The IRS treats withheld payroll funds as money you're holding in trust, and it enforces those deposits harder than almost any other obligation.
Estimated Quarterly Taxes: The Cash-Flow Trap
Because the US tax system is pay-as-you-go, most business owners can't wait until April. If you expect to owe roughly $1,000 or more when you file, the IRS wants estimated payments four times a year. For the 2026 tax year the federal quarterly deadlines fall in April, June, September, and the following January (the first two quarters are front-loaded and unevenly spaced, which trips up new owners).
The danger isn't the rate, it's the rhythm. A contractor who bills large jobs in spring can face a June estimated payment during a slow stretch, using cash earned in a completely different quarter. Underpay and you don't just owe the tax later, you owe an underpayment penalty calculated like interest. Many owners either overpay to stay safe and starve their working capital, or underpay and get hit at filing. Neither is a cash-flow strategy; both are symptoms of trying to fund a lumpy obligation out of lumpy revenue.
Payroll and Sales Tax: Money You Hold in Trust
Two obligations deserve their own warning because the money was never really yours. Payroll withholding and sales tax are trust-fund taxes: you collect them on behalf of the government from employees and customers, then remit them. Spending that cash to cover a slow week feels harmless in the moment and is one of the fastest ways a healthy business gets into trouble.
Sales tax is collected at the point of sale and remitted on a monthly, quarterly, or annual state schedule depending on your volume. Since the 2018 Wayfair decision, economic nexus rules mean you can owe sales tax in states where you have no physical presence at all, purely from remote sales crossing a dollar or transaction threshold. Payroll deposits, meanwhile, follow a semiweekly or monthly IRS schedule tied to your deposit history. The trust-fund recovery penalty can reach personally responsible individuals, so 'the business couldn't pay' is not a shield here. Treat these as segregated dollars, not spendable revenue.
How Your Entity Type Changes What You Owe
Entity choice is the single biggest lever on your tax obligations. The table below shows how the same profit is treated across common structures. Figures are illustrative only and simplified to show the mechanics, not a tax calculation for your situation.
| Entity type | Who pays income tax | Self-employment / payroll | Typical filing form | Underwriter note |
|---|---|---|---|---|
| Sole proprietor | Owner, on personal return | Full self-employment tax on net profit | Schedule C with Form 1040 | Simplest, but heaviest SE-tax load |
| Partnership / multi-member LLC | Partners, pass-through | SE tax on each partner's share | Form 1065 + K-1s | Cash distributions can lag tax owed |
| S-corporation | Shareholders, pass-through | Payroll on 'reasonable salary'; distributions exempt from SE tax | Form 1120-S + K-1s | Must run real payroll; deposits are non-negotiable |
| C-corporation | The corporation itself | Payroll on all wages | Form 1120 | Entity-level cash reserve needed for the corporate bill |
The S-corp election is popular precisely because owner distributions escape self-employment tax, but it comes with a mandatory payroll obligation and quarterly deposits. More structure means more discipline, not less.
A Real Example: When the Tax Date Beats the Deposit Date
Consider a specialty subcontractor, structured as an S-corp, whose work is seasonal. For example, they close two large commercial jobs in March and April, so first-half revenue looks strong on paper. Their September estimated payment and ongoing payroll deposits, however, fall during a summer lull when receivables from those spring jobs have already been spent on materials and labor for the next bid.
On the books the business is profitable. In the bank account, the tax due date arrives three months ahead of the cash that's supposed to cover it. This is the classic mismatch: the obligation is real and predictable, but the timing of revenue is not. The owner's options are to short the deposit and invite penalties, delay payroll to their crew, or bridge the gap. A short-term, revenue-based bridge that's repaid as the next round of receivables clears keeps the crew paid and the deposits current without gutting reserves. The math to watch is whether your expected near-term deposits comfortably absorb the daily or weekly remittance, not a single lump payment.
Decision Framework: Should You Fund a Tax Obligation?
Borrowing to pay taxes is a legitimate move when it protects trust-fund compliance and preserves working capital, and a mistake when it papers over a shrinking business. Here's the underwriter's line.
Revenue-based bridge financing works best when:
- The obligation is a timing gap, not a solvency problem, and you can point to specific receivables or seasonal revenue arriving soon.
- You're protecting payroll deposits or sales-tax remittances, where penalties and personal liability are steep.
- You need funds in 24 to 48 hours and can't wait on a bank's weeks-long underwriting before a deposit deadline.
- Your credit is thin or rebuilding (FICO around 500 or higher) but your bank deposits show consistent, real revenue.
- The near-term cost of penalties, liens, or a stopped payroll clearly exceeds the cost of a short bridge.
Avoid financing the tax bill when:
- Revenue is structurally declining and each period's tax is larger than the last relative to income; financing only defers a reckoning.
- You'd be stacking a new advance on top of existing daily-remittance obligations your deposits can't jointly support.
- An IRS installment agreement or a payment plan with the state would carry lower carrying cost and you have the runway to use it.
- The shortfall is chronic rather than seasonal. Fix pricing, collections, or overhead first.
If it's a timing mismatch and the fundamentals are sound, bridging is often the cheaper mistake. If it's a solvency signal, financing is the more expensive one.
Funding Options When a Tax Bill Is Due Now
When a deposit deadline is bearing down, the practical menu is short. IRS and state installment agreements are the lowest-cost path if you qualify and have time to set them up, though they still accrue interest and can require financial disclosure. A traditional bank line of credit is cheap capital, but approval timelines and credit thresholds rarely fit a 30-day tax clock, and many newer or credit-challenged businesses won't qualify.
For owners who need speed and are judged on revenue rather than credit score, a revenue-based advance or MCA marketplace is the common bridge. Approval leans on your bank deposits and top-line revenue instead of collateral or a strong FICO, funding typically lands in 24 to 48 hours, minimums start around $10,000, and owners with FICO of roughly 500 or higher can qualify. A marketplace matters here because it shops multiple funders against one application, so you see competing offers instead of a single take-it-or-leave-it quote. No responsible funder can call approval guaranteed, and you should be skeptical of anyone who does. Match the repayment rhythm to your deposit rhythm: daily or weekly remittances should sit comfortably inside your expected cash flow, not on top of it. For the bigger picture on structuring short-term capital, see our guides on business cash-flow management and working capital financing.
Frequently asked questions
What taxes does a small business actually have to pay?
Most US small businesses owe some combination of federal income tax, self-employment or payroll taxes (Social Security and Medicare), state income tax where applicable, and sales tax if they sell taxable goods or services. Employers also make federal payroll deposits, and some industries owe excise taxes. Your entity type — sole proprietor, partnership, S-corp, or C-corp — determines exactly which apply and who pays them.
When are small business estimated taxes due in 2026?
Federal estimated taxes for the 2026 tax year are due in four installments, roughly in April, June, and September of 2026 and January of 2027. The quarters are not evenly spaced, which catches many owners off guard. If you expect to owe about $1,000 or more at filing, you generally need to make these payments to avoid an underpayment penalty.
What happens if I can't pay my payroll or sales tax on time?
These are trust-fund taxes — money you collected from employees or customers on the government's behalf — so the IRS and states enforce them aggressively. Missing payroll deposits can trigger the trust-fund recovery penalty, which can reach owners and responsible individuals personally. Late sales tax brings penalties and interest and can jeopardize your seller's permit. Protecting these obligations is the strongest case for a short bridge if cash is momentarily tight.
Is it a good idea to borrow money to pay taxes?
It can be, when the shortfall is a timing gap rather than a solvency problem. If specific receivables or seasonal revenue are arriving soon and you're protecting payroll deposits or sales-tax remittances, a short revenue-based bridge often costs less than the penalties or a stopped payroll. It's the wrong move when revenue is structurally declining or the shortfall is chronic — in those cases, fix the underlying business or pursue an IRS installment agreement first.
How does an S-corp change my tax obligations?
An S-corp is a pass-through entity, so profit flows to shareholders' personal returns, but owners must pay themselves a reasonable salary through payroll. The advantage is that distributions above that salary aren't subject to self-employment tax. The trade-off is a mandatory payroll obligation with regular IRS deposits, so you take on more compliance discipline in exchange for the tax savings.
Can I get funding for a tax bill with bad credit?
Often yes, through a revenue-based advance or MCA marketplace that underwrites on your bank deposits and revenue rather than your credit score. Owners with FICO around 500 or higher can typically qualify, minimums start near $10,000, and funds usually arrive in 24 to 48 hours. Be wary of any funder that promises guaranteed approval — no legitimate one can.
How fast can I get funds to cover a tax deadline?
A revenue-based advance or marketplace can typically fund in 24 to 48 hours because approval leans on bank statements instead of collateral appraisals and lengthy credit review. That speed is the main reason owners use it for tax deadlines a bank line of credit can't meet in time. Confirm that the daily or weekly repayment fits inside your expected deposits before you accept.
Do I owe sales tax in states where I have no office?
Possibly. Since the 2018 Wayfair Supreme Court decision, economic nexus rules mean you can owe sales tax in a state purely because your remote sales cross that state's dollar or transaction threshold, even with no physical presence there. If you sell across state lines, review each state's nexus thresholds so you don't accumulate an unexpected multi-state sales-tax liability.
