Converting a sole proprietorship or LLC: steps and tax cost

What are the ways to change a business's legal structure?

A sole proprietor can form an LLC or corporation and move the business into it. An existing LLC may be able to convert under state law, or its owners may form a new entity and transfer the business. Federal tax depends on the old and new classifications and on what assets, debt, cash, and ownership change; the state filing label alone does not settle it (sections 351 and 357). For income tax, an LLC can be ignored as separate from its owner (disregarded), taxed as a partnership, or taxed as a corporation. A disregarded LLC can still have separate employment and excise tax duties (IRS: LLC classification).

Start with the current and intended tax classifications, then check whether state law allows a direct conversion or requires a new entity and asset transfer. Before filing, calculate possible gain from assets, debt, cash, and ownership changes; check EINs, returns, state fees, and tax accounts. There is no fixed federal income-tax charge for changing legal form.

An S corporation election changes federal tax status without necessarily changing the LLC's legal form; see whether to elect S corporation status. A Form 8832 corporate election also does not itself change state-law form; see how LLCs are taxed.

Does moving a sole proprietorship into an LLC create federal tax?

Usually no, if the same individual owns the new single-member LLC and it remains disregarded for income tax. The owner still reports business income and expenses on Schedule C, and forming the LLC alone does not reset the tax basis of its assets (IRS: LLC classification). Net earnings from a trade or business generally remain subject to self-employment tax (IRS: Single-member LLCs).

The LLC is separate for employment tax and certain excise taxes, so a business with employees or excise tax duties must check its EIN and payroll accounts. A transfer of property, contracts, or permits can also have state consequences. If a second owner joins, the default federal classification changes to a partnership; the way that owner joins determines whether the first owner recognizes gain (entity classification regulation).

What tax applies when I move the business into a corporation?

The asset transfer may avoid immediate federal gain under section 351 if the property transferors receive stock and together control the corporation immediately afterward. Control requires at least 80% of the voting power and of each other class of shares (sections 351 and 368(c)). An investor contributing cash for stock in the same exchange can count as a property transferor; stock for services does not. A small property contribution made mainly to count service stock toward control may also be excluded. A planned issuance or sale to someone outside the transferor group can defeat control (section 351 regulation; section 351(d)).

Even when section 351 applies, cash or other property received alongside stock can trigger gain. If the corporation assumes liabilities greater than the combined adjusted tax basis of the transferred property, section 357(c) generally treats the excess as gain; the statute has exceptions for certain liabilities. A loan balance therefore needs to be compared with tax basis, which can be much lower than market value after depreciation (sections 351(b) and 357).

Before transferring assets, assemble a tax-basis balance sheet, depreciation schedules, loan balances, asset values, and a table showing who will own each class of stock immediately afterward. The actual documents and any simultaneous sale or investment matter to the control test.

What happens when a partnership-taxed LLC becomes a corporation?

For a state-law conversion with no actual asset transfer, the IRS treats a partnership-taxed LLC as contributing its assets and liabilities to the corporation for stock, then distributing the stock to its partners. A legal conversion can therefore be a federal tax transaction even when no deed or bill of sale is signed (Revenue Ruling 2004-59).

The transfer may qualify under section 351 when the property transferors satisfy its control test. Gain can still arise from cash or other property received, liabilities above asset tax basis, or other partnership-level and partner-level rules (sections 351 and 357). Check each member's interest basis and share of LLC debt: a decrease in that debt share can count as cash distributed, with gain if deemed cash exceeds basis (sections 752(b) and 731(a)). The deemed transaction is also the rule for an LLC that elects corporate classification, although whether to make that election belongs in how LLCs are taxed (entity classification regulation).

Why can converting a C corporation to a pass-through LLC create two taxes?

A C corporation that becomes an LLC taxed as a partnership or disregarded entity is generally treated as liquidating for federal tax. On a distribution of appreciated assets in a complete liquidation, the corporation generally recognizes gain as if it sold them at fair market value. Shareholders separately treat the liquidating distribution as payment for their stock, which may create another gain after their stock basis is considered (sections 336 and 331). The amount and character at each level depend on asset values, liabilities, and stock basis.

A corporation converting to an LLC can remain federally classified as a corporation if a valid Form 8832 corporate election is effective at conversion. Without it, a domestic LLC generally defaults to partnership or disregarded status, with possible liquidation tax. On Form 8832, select corporate status on Part I, line 6a, and the effective date on line 8. All current owners or an authorized officer, manager, or member sign; former owners affected by a retroactive election also sign. Generally, file within 75 days after, or 12 months before, that date (Form 8832 and instructions). For whether to make the election, see how LLCs are taxed. The built-in gains rules for a C corporation electing S status are a different question; see how S corporations are taxed.

What if a single-member LLC adds an owner, or one owner buys out the others?

The default classification of a domestic LLC changes from disregarded to partnership when it gains another owner, and from partnership to disregarded when only one owner remains. The owner's payment route changes the tax result (entity classification regulation).

These are the situations addressed in Revenue Rulings 99-5 and 99-6. Debt, inventory, receivables, and the precise sale terms can change the calculation. If a spouse is joining, see spouse and family LLCs before assuming a partnership return is needed.

Do I need a new EIN after converting?

Sometimes. The IRS ties the answer to the old and new entities and to whether the old entity ends, not just the name on the state filing (IRS: When to get a new EIN).

A disregarded LLC with employees or excise tax obligations needs its own EIN for those duties (IRS: When to get a new EIN). Check the EIN before moving payroll, tax deposits, or information reporting.

Which final and first returns are due in the conversion year?

File returns for the periods each tax classification applied. Which return reports an item depends on the accounting method and the transaction: a cash-method taxpayer generally reports income when received, while an accrual-method taxpayer generally reports it when earned (IRS: Accounting periods and methods). A change that ends a partnership or corporation can create a short tax year and a final entity return, followed by the new entity's first return (IRS: Closing a business; entity classification regulation).

For a section 351 exchange, the corporation and each significant property transferor generally include statements with their returns and keep records of transferred basis, value, and liabilities (section 351 statement regulation). A foreign-owned disregarded LLC with a reportable formation or contribution may also need Form 5472 attached to a pro forma Form 1120; see foreign-owned single-member LLC filing (Form 5472 instructions).

A terminated partnership generally files Form 1065 by the 15th day of the third month after its short year ends. A C corporation generally files Form 1120 by the 15th day of the fourth month after its year ends. A June-ending C corporation year begun before 2026 can have an earlier third-month deadline; check the year start and any extension (Form 1065 instructions; IRS: 2026 tax calendars).

Form 966 is required when a corporation adopts a resolution or plan to dissolve or liquidate stock, generally within 30 days. The form instructions expressly say not to file it for a deemed liquidation caused by an entity-classification election. For ongoing return types, see which returns a business files.

Can converting an LLC to a C corporation start section 1202 eligibility?

Potentially, if the conversion produces stock originally issued by a qualifying C corporation and the other section 1202 conditions are met. Conversion does not turn earlier LLC ownership into a period of owning qualified stock. For property transferred for stock, section 1202 treats the stock as acquired on the exchange date and sets a fair-market-value floor for its basis for section 1202 purposes, so appreciation built into the business before incorporation is outside the potential exclusion (section 1202(c), (d), and (i)).

Value the contributed assets at conversion and keep the stock issuance, ownership, and asset records. If a partnership distributes the stock to its members, section 1202(h) can preserve its treatment only for members who held their partnership interests when the partnership acquired the stock and continuously until distribution (section 1202(g) and (h)). The corporation's other qualification rules belong in LLC or C corporation.

What state filings and taxes come with a conversion?

State law decides whether the business can file a direct conversion and which document, fee, and agency apply. California, for example, accepts an LLC-to-corporation conversion through articles of incorporation with a statement of conversion; the listed filing fee is $150 (California Secretary of State). Other states and conversion routes differ.

Before filing, check the formation state and every state where the business is registered or operates. Confirm the conversion document, business licenses, employer account, sales tax permit, and any property transfer or reassessment rules. In California, a change of organization type requires a new sales tax account, while registered employers must report a legal-entity change to the payroll tax agency (CDTFA; EDD).

California real property can be reassessed after a change in ownership or control. A transfer that only changes how title is held may qualify for a proportional-ownership exclusion when every property's ownership shares remain the same. If there is a reportable change in control or ownership, Form BOE-100-B is due within 90 days even if an exclusion applies (California BOE: legal entity ownership; reassessment exclusions). California's annual minimum tax and LLC fee need their own conversion-year check; see California minimum tax and LLC fee.

Example

Illustrative amounts in US dollars. A sole proprietor transfers equipment with a $40,000 adjusted tax basis and a $100,000 fair market value into a corporation for all its stock. The corporation assumes a $25,000 business loan. If the transfer otherwise meets section 351 and no cash or other property is received, the $60,000 built-in appreciation generally is not recognized at the transfer. The $25,000 liability is below the $40,000 basis, so the section 357(c) excess-liability rule does not create gain on these facts.

If the loan were $55,000 instead, it would exceed the equipment's basis by $15,000. Subject to the statute's liability exceptions, that $15,000 would be recognized as gain even though the owner received only stock. The equipment's $100,000 value also matters if the owner later tests the stock under section 1202: pre-conversion appreciation is outside its potential exclusion. The actual calculation requires all transferred assets and liabilities, not just one asset.

Different for you?

• The business has appreciated assets, large loans, or several owners: calculate asset and owner tax bases and map the full transaction before signing conversion documents; business formation help can address the structure and filing sequence.
• The business owns real estate: property transfers and state reassessment can change the answer; see rental property in an LLC or get business formation help.
• You want an S corporation election without changing the LLC's legal form: see whether to elect S corporation status.
• You want to compare LLC and C corporation ownership before converting: see LLC or C corporation.
• You need to plan recurring returns or California entity taxes: see which returns your business files and California minimum tax and LLC fee.