The difference between Corp to Corp and 1099 contracting comes down to who signs the contract. In a Corp to Corp arrangement, the hiring company signs a service agreement with your business entity, usually an S-corporation or an LLC taxed as one. In a 1099 arrangement, the hiring company contracts with you personally as a sole proprietor. That single structural choice changes how the IRS sees your income, who pays employment taxes, how much personal liability you carry, and how much overhead you take on to keep the arrangement running.
Who Signs the Contract
A 1099 contractor works as an individual. Payments come to you, tax responsibility sits with you, and there is no legal buffer between the work and your personal finances. It is the simpler setup and it fits short-term projects and specialized consulting where forming a corporation would be overkill.
A Corp to Corp worker forms a legal entity before the engagement begins, typically an S-corporation, a C-corporation, or an LLC that has elected corporate tax treatment. The hiring company then treats your corporation the same way it would treat any other vendor. Because the contract runs business-to-business, the corporate veil generally shields your personal assets if a dispute over the project arises.
One point that catches new S-corp owners off guard: if you perform services through your S-corp, the IRS treats you as an employee of your own company. Your corporation has to put you on payroll, withhold income tax and FICA, and issue you a W-2 at year’s end. Courts have consistently upheld this even when owners tried to take all their compensation as distributions.
How Income Gets Reported to the IRS
Starting in 2026, a business that pays an individual $2,000 or more during the calendar year for nonemployee services must file Form 1099-NEC with the IRS and send the worker a copy. The threshold sat at $600 for decades before the One Big Beautiful Bill Act raised it for payments made after December 31, 2025, with inflation adjustments beginning in 2027.1Internal Revenue Service. 2026 Publication 1099 (Draft)
Payments to a corporation are generally exempt from 1099-NEC reporting. Federal regulations classify corporations as exempt recipients, so a hiring company does not file a 1099-NEC when it pays your S-corp or C-corp for services.2eCFR. 26 CFR 1.6041-3 – Payments for Which No Return of Information Is Required Under Section 6041 Two exceptions apply: payments to corporations for legal services and payments to corporations providing medical or health care services still require a 1099. Instead of receiving a 1099, your corporation tracks its own revenue through invoices and reports the income on Form 1120 for a C-corp or Form 1120-S for an S-corp.3Internal Revenue Service. About Form 1120, U.S. Corporation Income Tax Return
Both arrangements start the same way. The hiring company collects a Form W-9 to get the correct taxpayer identification number and tax classification. A sole proprietor supplies a Social Security number; a corporation supplies an Employer Identification Number. The W-9 also tells the payer whether you qualify as an exempt recipient, which is how the Corp to Corp exemption gets documented before any money moves.4Internal Revenue Service. Instructions for the Requester of Form W-9
Quarterly Estimates for 1099 Workers
Sole proprietors who expect to owe $1,000 or more in federal taxes for the year have to make quarterly estimated payments using Form 1040-ES. For the 2026 tax year, the deadlines are April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027. Missing them triggers underpayment penalties, and this obligation surprises many first-time contractors who are used to employer withholding.
How Employment Taxes Split
This is where the structures really diverge. A sole proprietor pays self-employment tax on all net earnings from the business. The combined rate is 15.3%: 12.4% for Social Security on net earnings up to $184,500 in 2026, and 2.9% for Medicare on all net earnings with no cap.5Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)6Social Security Administration. If You Are Self-Employed You calculate this on Schedule SE and report it on your individual return. You can deduct half of the self-employment tax when calculating adjusted gross income, which softens the blow but does not reduce the self-employment tax itself.7Internal Revenue Service. Topic No. 554, Self-Employment Tax
In a Corp to Corp setup with an S-corp, your corporation runs payroll for you. It withholds 7.65% from your paycheck (6.2% Social Security plus 1.45% Medicare) and pays a matching 7.65% as the employer share. The rate looks identical to self-employment tax, but the base is different: FICA applies only to the salary portion. Any remaining corporate profit taken as a shareholder distribution is not subject to FICA. A sole proprietor pays self-employment tax on the entire net. That gap between salary and distributions is the single biggest tax advantage of the S-corp route, and it is also where the IRS looks hardest.
Both structures face an additional 0.9% Medicare surtax on earnings above $200,000 for single filers, $250,000 for married filing jointly, and $125,000 for married filing separately. For a 1099 contractor, it applies to self-employment income above the threshold. For an S-corp employee, the corporation must begin withholding the extra tax once wages pass $200,000 in a calendar year, regardless of filing status.8Internal Revenue Service. Topic No. 560, Additional Medicare Tax
Reasonable Compensation and the QBI Deduction
The FICA savings on distributions only survives if the salary you pay yourself qualifies as “reasonable compensation” for the services you perform. Setting the salary artificially low to shift more income into distributions is a well-known strategy that the IRS and Tax Court have shut down repeatedly, with distributions reclassified as wages plus penalties and interest.9Internal Revenue Service. S Corporation Employees, Shareholders and Corporate Officers There is no bright-line rule. The IRS weighs what similar professionals earn, the time and effort you put in, and the corporation’s revenue.
Both sole proprietors and S-corp shareholders can claim the Qualified Business Income deduction under Section 199A. The One Big Beautiful Bill Act made the deduction permanent in July 2025 and increased it from 20% to 23% of qualified business income. C-corporation income does not qualify.10Internal Revenue Service. Qualified Business Income Deduction
The interaction matters. A sole proprietor’s entire net business income generally counts as QBI. An S-corp shareholder’s QBI covers only the pass-through profit, not the W-2 salary. So the salary you pay yourself to satisfy reasonable compensation reduces your QBI and shrinks the deduction. The optimal salary is the lowest defensible figure the IRS would accept, and finding it is where real planning happens. Higher-income taxpayers also face additional limitations tied to the type of business, W-2 wages paid, and business property basis.
Liability and Misclassification Exposure
Because a 1099 contractor has no separate entity, there is no legal barrier between business obligations and personal assets. A Corp to Corp structure puts a corporation in between, which is one of the reasons hiring companies sometimes prefer it and often require professional liability insurance on top.
The other exposure runs the other direction. Companies sometimes push workers into 1099 or Corp to Corp arrangements to avoid employment taxes, benefits, and unemployment insurance. If the IRS decides the worker was actually an employee based on the level of control the company exercised, the penalties fall on the hiring company.11Internal Revenue Service. Worker Classification 101: Employee or Independent Contractor Under Section 3509 of the Internal Revenue Code, a misclassifying employer owes 1.5% of the worker’s wages for the income tax withholding that should have occurred plus 20% of the employee’s share of FICA, and both rates double to 3% and 40% if the employer also failed to file required information returns.12Office of the Law Revision Counsel. 26 U.S. Code 3509 – Determination of Employers Liability for Certain Employment Taxes
A Corp to Corp structure insulates against reclassification better than a 1099 arrangement. When you operate a genuine corporate entity with its own payroll, bank accounts, and multiple clients, it is harder for the IRS to argue you are really an employee of one hiring firm. A 1099 contractor who works exclusively for one company, follows that company’s schedule, and uses that company’s equipment is in a much weaker position if the classification gets challenged.
The Cost of Running the Corporate Entity
Corp to Corp costs more to operate than a 1099 setup. The overhead is real and recurring.
- State filing fees for annual or biennial reports, ranging from $0 in a handful of states to over $800 in California, with a typical figure around $50 to $150.
- Payroll processing, since S-corp owners have to run payroll for themselves, either through software or a service provider.
- Corporate tax returns; Form 1120-S is more complex than the Schedule C a sole proprietor attaches to a personal return, and most S-corp owners hire an accountant.
- Insurance. Hiring companies in Corp to Corp engagements frequently require professional liability coverage, often with minimum limits of $1 million per claim, and a Certificate of Insurance before work starts.
For workers earning enough to benefit from the FICA savings on distributions and the QBI deduction, the tax advantages of an S-corp typically outweigh the overhead by a significant margin. The breakeven depends on total income, the reasonable compensation figure, and state-specific costs, but most accountants start recommending S-corp election once net self-employment income consistently exceeds roughly $50,000 to $60,000 per year. Below that, a 1099 sole proprietorship is usually the simpler and cheaper answer.