The formula behind technology ventures that reach billion-dollar valuations is not flawless code or a genuinely disruptive idea alone. In practice, success is measured by how solidly the founders built the company's legal foundation before letting investors in.
Across funding rounds in both Silicon Valley and the Turkish ecosystem, from seed to Series A, hundreds of startups with excellent products have hit the legal due diligence wall. The cause is rarely the product. It is the amateur legal shortcuts taken at incorporation, which cost founders their funding or, in the worst cases, their position in the company they built.
At Ertuğ & Partners, we set out the 11 costly mistakes that directly depress a startup's valuation and push investment funds away from the table.
MISTAKE #1: Not Signing a Founders' Agreement
You may have started the company with a close friend. But once the business begins to generate real money, or once a crisis hits, verbal understandings do not survive a courtroom. Founders should put the difficult scenarios on paper from day one:
MISTAKE #2: The Sole Proprietorship or Limited Company Trap
Incorporating a technology venture as a sole proprietorship or a limited liability company (Ltd. Şti.) because registration is cheaper, or because an accountant suggested it, creates problems that are expensive to unwind later.
MISTAKE #3: Registering Trademarks, Patents and IP in Your Own Name
Investors are not buying the startup; they are buying the intellectual property it owns.
MISTAKE #4: Launching on Top of Someone Else's Trademark
Choosing a name after a quick Google search and concluding "nobody seems to be using it" opens the door to serious litigation. A mark that is not registered before TÜRKPATENT or WIPO is a red flag in an investor's due diligence report. A professional clearance search before launch is the only reliable protection against an infringement claim from the true owner, or a domain name arbitration (WIPO UDRP).
MISTAKE #5: Informal Employment and Copyright Arrangements
You may not have signed a contract with the developer or designer you hired. Even without a written contract, mandatory employment terms apply from the moment social security registration begins. On the intellectual property side, however, the picture differs from what most founders assume:
MISTAKE #6: Copying and Pasting Data Protection Policies
User data is the lifeblood of a digital startup. If the privacy notice and privacy policy on your app or website were copied from another company:
MISTAKE #7: Failing to Anticipate Licences and Permits
You are building a fintech but have not obtained the operating licence required from the Central Bank of Türkiye for payment and electronic money services, or from the BDDK for banking activities. Or you are building a health technology product without ever assessing whether it qualifies as a medical device. In Türkiye, medical devices are regulated by the Turkish Medicines and Medical Devices Agency (TİTCK), and conformity certificates are issued not by the Ministry but by authorised notified bodies.
You may build outstanding technology and still have the regulator shut it down. Whether the product falls into a restricted or regulated market must be assessed in advance.
MISTAKE #8: Not Keeping Corporate Books
When an investor asks to see your share ledger and board resolution book, answering "we never had them notarised, we do everything verbally" ends the process that same day. Under the Turkish Commercial Code, tax and commercial decisions must be recorded in duly certified statutory books.
MISTAKE #9: Weak B2B and B2C Customer Contracts
Selling to consumers (B2C) under an incomplete or unfair distance sales agreement, or to corporate customers (B2B) under standard service agreements with no liability caps, exposes a startup to consumer claims and product liability awards it cannot absorb.
MISTAKE #10: Postponing Accounting and Tax
Skipping tax filings in the first year out of founder enthusiasm, or leaving social security premiums unpaid on the assumption that the state will offer a restructuring later, is a red card the moment an angel investor looks at the company. Tax debt is the one liability that reaches through to a founder's personal bank accounts if the company fails.
MISTAKE #11: Working With a Lawyer Who Is a Friend Rather Than a Specialist
Technology ventures are nothing like ordinary commercial or family litigation. They are combined operations spanning securities, angel investment, option pools (ESOP), intellectual property, IT and international tax law. Working with a non-specialist to save cost is how pathological clauses (provisions that collapse when tested) find their way into your contracts.
This report is a strategic analysis of the critical failure points in the formation of innovative ventures. It does not constitute binding legal advice.
Last updated: 10 August 2026.
