From the moment a company picks its underwriters to the morning its shares start trading, an IPO typically takes six to twelve months. That answers how long an IPO takes in the narrow sense, but the fuller answer is longer: internal preparation usually begins a year or more before any paperwork reaches the SEC, and the lock-up restrictions that shape the offering’s aftermath run for months after the first trade. Companies that treat the timeline as a six-month sprint tend to scramble through the regulatory phase or pull the offering when markets turn.
The Year Before Filing
Most of the schedule risk in an IPO sits in the pre-filing phase, because the work here has no fixed clock. A company selects investment banks to underwrite the offering, retains outside legal counsel, and hires auditors to scrub its financial history. If the books are messy or the accounting team has been tracking finances informally, getting the numbers audit-ready can consume the bulk of the preparation window on its own.
The audited financials must follow U.S. Generally Accepted Accounting Principles. The SEC treats any financials not prepared under GAAP as presumptively misleading.1U.S. Securities and Exchange Commission. Financial Reporting Manual – Topic 1 – Registrants Financial Statements Whether the company needs two years or three of audited statements depends on its status as an Emerging Growth Company. Any company with less than $1.235 billion in annual gross revenue that hasn’t previously sold stock through a registration statement can claim EGC status for the first five fiscal years after the IPO. EGCs only need two years of audited financials in their filing, while larger companies must provide three, and EGCs are exempt from the Sarbanes-Oxley requirement that an outside auditor attest to internal financial controls.2U.S. Securities and Exchange Commission. Emerging Growth Companies Most IPO-bound companies qualify, and the reduced requirements can shave weeks off preparation.
In parallel, the company forms a compliant board of directors with independent members (a listing condition on major exchanges) and confirms it meets the financial thresholds of whichever exchange it targets. Choosing the exchange early lets the company tailor its disclosures to the right listing standards rather than rework them later.
Cost tracks time here. Underwriting fees alone typically run 4% to 7% of the money raised. PwC’s analysis of roughly 1,300 IPOs from 2015 to 2024 found total costs, including legal, accounting, printing, SEC registration, FINRA filing, and exchange listing fees, averaged between $9.3 million and $18.5 million.3PwC. Considering an IPO? First, Understand the Costs
Drafting the S-1: Several Months
The S-1 registration statement is the core document of the IPO. It pulls together the business model, risk factors, intended use of proceeds, audited financials, management biographies, and executive compensation. Drafting it commonly takes several months on its own. Legal teams, accountants, and underwriters cycle through multiple rounds of review, and every forward-looking claim needs supporting data, every risk factor enough specificity to actually warn investors.
One timing feature worth knowing: since 2017, the SEC has allowed all companies (not just EGCs, which have had the option since the 2012 JOBS Act) to submit the S-1 confidentially for nonpublic staff review.4U.S. Securities and Exchange Commission. Enhanced Accommodations for Issuers Submitting Draft Registration Statements Confidential submission lets a company work through SEC comments without publicly revealing its financials or its intention to go public. The registration statement must be publicly filed at least 15 days before the roadshow begins, but by then most of the SEC’s major concerns are already resolved in private. If markets turn and the company decides not to proceed, no one outside the deal team knows the filing existed.
SEC Review: Roughly Two Months of Back-and-Forth
After the S-1 is submitted, the SEC’s Division of Corporation Finance reviews it and typically issues its first comment letter within about 30 days. The comments are detailed and specific: clearer disclosure of a related-party transaction, questions about the assumptions behind a revenue projection, a request that a risk factor explain exactly how a regulatory change could affect the business.
The company responds with amendments labeled S-1/A. This back-and-forth usually repeats two or three times and spans about two months total, though complex situations run longer. Once the staff is satisfied, it declares the registration statement effective, and the company can sell shares.
The Roadshow: Seven to Ten Trading Days
With a preliminary prospectus (the red herring) in hand, the executive team hits the road. The roadshow typically runs about seven to ten trading days and packs the schedule with presentations to institutional investors: pension funds, mutual funds, hedge funds, and insurance companies. These are the buyers who will absorb the bulk of the offering.
While executives present, the underwriters run book-building. Each institutional investor indicates how many shares it would buy and at what price range, and the book fills in real time. If it is heavily oversubscribed, the company and underwriters may raise the price range; if demand is soft, they lower it or rethink the offering size. The roadshow’s compressed schedule is deliberate, and its data drives the final pricing decision.
Pricing and the First Trade
The transition from private to public happens fast at the end. After the roadshow closes, the company and its lead underwriters typically meet that same evening to set the final offer price based on demand and current market conditions. Price too high and the stock drops on opening day; price too low and the company leaves money on the table.
Once the price is set, the company signs a formal underwriting agreement binding the banks to purchase the shares for resale. The stock is then listed under a ticker symbol the company reserved earlier in the process. NYSE, for example, allows companies to reserve a symbol up to 24 months before listing and typically responds to requests within 48 to 72 hours.5NYSE. Reserve Your Ticker Symbol The next morning, shares begin trading publicly.
Most underwriting agreements also include an overallotment option, commonly called a green shoe, giving the underwriters the right to buy up to 15% more shares from the company at the offering price. Underwriters use it in the first days of trading to stabilize the price: they deliberately oversell to create a short position, then either cover in the open market if the stock drops (supporting the price) or exercise the option if it rises. This shapes how the first week of trading feels, but it does not extend the IPO timeline itself.
The Lock-Up: 90 to 180 Days After Trading Begins
The IPO’s clock does not fully stop on listing day. Founders, executives, employees with stock options, and early investors generally cannot sell their shares immediately. Underwriters require them to sign lock-up agreements that typically last 90 to 180 days. These are contractual, not imposed by securities regulation, and they exist because flooding the market with insider shares right after the IPO would drive the price down and undermine the offering.
The lock-up expiration date is worth marking. When it arrives, a large block of previously restricted shares becomes eligible to sell, and the stock often dips as some insiders cash out, even when the company’s fundamentals have not changed.
Putting the Timeline Together
A realistic schedule for a company going public looks roughly like this. Internal preparation, including audit cleanup, board formation, and underwriter selection, runs a year or more and is the phase most likely to slip. S-1 drafting takes several months, often overlapping the tail end of preparation. SEC review adds about two months from first comment letter through effectiveness. The public filing sits for at least 15 days before the roadshow, which itself runs seven to ten trading days. Pricing happens the evening the roadshow ends, and trading begins the next morning. Lock-ups then govern insider selling for another 90 to 180 days.
Six to twelve months captures the formal process. The full arc from boardroom decision to a stabilized public stock is closer to two years, and the parts of it that a company can control are almost all in the preparation phase.