The IRS Proposed $85,000 in Taxes on a $13,000 Gain. The Investor Did Nothing Wrong.
A quiet structural problem is inflating crypto tax bills across the board. Here is what it is, why it happens, and what to do about it before you file.
The investor had been reporting their crypto taxes for years.
They used a CPA. They declared their gains and losses. They filed on time. When the IRS began requiring a checkbox on Form 1040 asking whether you had transacted in digital assets, they checked the correct box. By any reasonable standard, they were doing everything right.
Then the notice arrived.
The IRS was proposing a tax assessment of $85,000. The investor's actual gain — the difference between what they paid for their assets and what they received when they sold — was $13,000. The discrepancy was not the result of fraud, error, or evasion. It was the result of a documentation gap so common that tax attorneys have given it a name.
The investor had moved their assets between platforms over the years. The exchange that reported their sale to the IRS had no record of what they originally paid. From the IRS's perspective, the asset appeared to have cost nothing. Every dollar received looked like a taxable gain.
The case was ultimately resolved. The investor was able to reconstruct their cost basis with supporting records. But the resolution required professional intervention, additional documentation, and time — costs that would have been entirely avoidable with the right infrastructure in place.
That infrastructure exists. Most people promoting it are explaining its features. This piece explains why you need it.
The System Was Never Built for This
In traditional finance, cost basis documentation is a solved problem.
When you buy shares through a brokerage and later transfer them to a different brokerage, the two institutions communicate. The record of what you paid — your cost basis — travels with the asset. You receive a 1099-B at tax time that shows both your proceeds and your cost basis. The documentation is handled automatically, by the intermediaries, without any action required from you.
This infrastructure took decades to build. It is the product of regulatory requirements, institutional agreements, and standardized data formats that the securities industry developed over time.
Cryptocurrency was not built on this infrastructure. It was built on something philosophically different: a decentralized ledger that records what happened without requiring any institution to mediate the transaction. That architecture is genuinely powerful. It is also the reason your cost basis disappears.
When you move a crypto asset from one platform to another — from Coinbase to MetaMask, from MetaMask to a DeFi protocol, from Ethereum to Base via bridge — each platform records only what happened within its own system. The exchange where you originally bought the asset recorded your purchase. Every subsequent platform recorded only the arrival and, eventually, the departure. No platform forwarded your cost basis to the next one. There was no mechanism to do so and no requirement to try.
The regulatory framework that governs how you report these transactions was designed for the securities world, not this one. The IRS's treatment of cryptocurrency as property — every trade, swap, and bridge potentially a taxable event — was drafted when most crypto activity consisted of buying Bitcoin on a single exchange and occasionally selling it. The rules have not kept pace with what crypto actually looks like now: multi-chain, multi-wallet, algorithmically active, with thousands of micro-transactions per year across protocols that did not exist when the legislation was written.
Into this gap, in early 2026, arrived Form 1099-DA.
Your exchange is now required to report your crypto proceeds directly to the IRS. For the 2025 tax year, this means the IRS has received a record of every sale you executed on a centralized platform — the date, the asset, the amount received. What the form does not contain — because your exchange is not required to provide it and often cannot — is your cost basis. The IRS has the proceeds. You are responsible for substantiating the cost.
If you cannot substantiate it, the IRS is permitted to treat your cost basis as zero.
Every dollar you received looks like a taxable gain. The $13,000 profit becomes an $85,000 assessment.
Why the Obvious Answers Don't Work
The natural response to this problem has been to try to solve it manually, or to delegate it to a professional, or to trust that existing software would handle it.
None of these approaches addresses the root cause.
The spreadsheet works for simple portfolios. If you bought Bitcoin on one exchange in 2021 and sold it on the same exchange in 2025 without touching it in between, a spreadsheet is adequate. But for anyone who has used multiple exchanges, moved assets between wallets, bridged to L2 networks, or participated in DeFi in any form, the spreadsheet is not a solution — it is a record of the transactions you can see, which is a different thing from a complete record of your cost basis chain. The errors it misses are invisible precisely because it cannot know what is missing.
General-purpose tax software was not built for this either. TurboTax and its equivalents were designed for the world that Form 1099-B inhabits — a world where brokerages share cost basis information and the documentation arrives pre-packaged. When a crypto asset appears in these platforms, the default treatment in the absence of documentation is often a zero cost basis. The software is not malfunctioning. It is applying the rules correctly to the data it has. The problem is the data.
Dedicated crypto tax tools are closer, but they share a common structural failure that a user on r/CryptoTax identified with precision: "I connected all my wallets to CoinTracker, CoinLedger, and Koinly — all three show different gains/losses. How am I supposed to figure out which one to go with?"
This is not a coincidence. The tools disagree because they handle wallet-ownership context differently. When software sees an asset leave one address and arrive at a different address, it has to make a decision: was that a sale, or was that a transfer between wallets owned by the same person? The answer determines whether a taxable event occurred. Different tools make different assumptions. None of them can know the answer without additional context that the blockchain does not provide.
The result is what one user described as paying $200 for a number they have no rational basis for trusting.
The accountant is the most expensive non-solution. Most CPAs have no specialized training in crypto — industry surveys consistently show that the majority of general practitioners who encounter crypto in a client's portfolio are not equipped to reconcile it accurately. The specialists who are equipped charge $50 to $400 per hour. For a user with thousands of DeFi transactions, the cost of professional reconciliation routinely exceeds the actual tax liability. As one r/CryptoTax user stated without apparent irony: "The cost of the accountant to fix my 15,000 micro-transactions is higher than the tax I actually owe."
Every one of these approaches shares a single failure point. They are all working from incomplete data, and none of them were designed to solve the specific problem that generates the incomplete data in the first place.
Basis Evaporation — The Process That Is Inflating Your Tax Bill
The reason every approach above falls short has a name.
Every time you move a crypto asset between platforms — from exchange to wallet, from wallet to bridge, from one chain to another — the cost basis record of what you paid stays behind at the platform where you originally acquired it. The asset moves forward. The documentation does not.
This is not a software failure. It is not a regulatory gap that will be patched next year. It is a structural feature of how decentralized financial infrastructure was built, applied against a tax system that was designed to work with centralized institutions that communicate with each other.
Call it Basis Evaporation.
The ETH you bought on Coinbase in 2020 has a purchase record on Coinbase. When you moved it to MetaMask, MetaMask recorded an incoming transfer — not a purchase. When you bridged it to Base, the bridge contract recorded an exit from Ethereum and an entry on Base. When you eventually sold it on Kraken in 2025, Kraken recorded a sale. Of the four records that should collectively tell the story of that asset's life, Kraken — the platform that issued your 1099-DA — has access to only one: the sale.
This is why the IRS can propose $85,000 in taxes on a $13,000 gain without being wrong. From the data available to them, they cannot see the gain was $13,000. They see the proceeds. They do not see the cost basis. In the absence of documentation, the rules permit them to assume zero.
The 1099-DA has made this problem visible in a way it was not before. For years, the IRS did not have the proceeds data to identify the discrepancy. Now they do. Anyone whose cost basis documentation evaporated through legitimate transfers is now generating a potential mismatch between what they file and what the IRS received — and the IRS's automated systems are increasingly designed to catch exactly this kind of mismatch.
The solution to Basis Evaporation is not better arithmetic. It is a system that tracks the asset through every move rather than leaving the documentation stranded at the platform of origin.
That is what Koinly's Smart Transfer Matching does.
When you connect your wallets and exchanges to Koinly — all of them — Koinly does not treat each one as a separate financial universe with its own accounting. It builds a unified ownership map. Every address you declare becomes part of a single ledger. When Koinly sees an asset leave one of your declared addresses and arrive at another one of your declared addresses, it does not generate a disposal event. It marks the movement as an internal transfer, preserves the original cost basis, and produces no taxable gain — because there was none.
The ETH bought on Coinbase in 2020 is still, in Koinly's ledger, the ETH bought on Coinbase in 2020 — with its 2020 cost basis intact — regardless of how many wallets, bridges, and chains it has traveled through since. When your 1099-DA arrives showing gross proceeds with a blank cost basis field, Koinly has the full chain of custody. It reconciles what your exchange reported against the complete history it has been tracking. The blank gets filled. The number you file reflects what actually happened.
Not because you guessed. Because you documented it.
What 2 Million Investors Already Know
Koinly is currently trusted by over 2 million investors across 140 countries — a user base that has grown substantially in the years since multi-chain DeFi activity made manual tax reconciliation genuinely impractical for the average investor.
On Trustpilot, it carries a 4.6-star rating across more than 2,200 verified reviews — one of the highest ratings in the category. The platform holds SOC 2 and ISO 27001 security certifications, is GDPR compliant, and uses read-only API connections throughout, meaning it can view your transaction history but cannot move funds, execute trades, or access your holdings in any way.
The language that appears consistently in long-term user reviews is notable for what it doesn't say. There are no claims of overnight simplicity or tax seasons transformed into pleasant experiences. What users describe, accurately, is a difficult problem that became manageable. "Only software that made my crypto taxes possible with multiple wallets and complex data structure of my transactions." "A bit of a life saver — I've been able to organise wallets from five exchanges into a single HMRC-compliant set, spanning five years." "The best I've been able to find in this space — not perfect, but consistently improving."
That last characterisation is the honest one. No tool handles every conceivable edge case in a rapidly evolving DeFi ecosystem. Complex cross-chain activity may still require some degree of manual review for the most exotic transaction types. What Koinly handles automatically — through 1,000+ direct API integrations and recognition of more than 7,000 DeFi protocols — covers the vast majority of the activity that generates Basis Evaporation errors: bridges, wallet transfers, staking rewards, LP entries and exits, DEX swaps. The manual exceptions exist at the edges, not at the centre of most users' tax problems.
For those with genuinely complex situations — high-volume DeFi activity across multiple chains, legacy data from defunct exchanges, or portfolios that span multiple jurisdictions — Koinly offers an Expert Review service: a human specialist who reviews your account, verifies the data, and confirms the report is accurate before you file. Pricing is quote-based given the variation in complexity and jurisdiction. It exists for the cases where software confidence alone is not enough.
One feature that distinguishes Koinly from most of its competitors before any payment is required: the free plan supports tracking of up to 10,000 transactions. Most comparable platforms cap free tracking at 250 to 1,000 transactions. On Koinly's free tier, unlimited wallet and exchange integrations are available, portfolio tracking is fully functional, and a complete capital gains preview — including your full gains, losses, and income picture across every connected account — is visible before you pay anything. A paid plan is only required when you are ready to download the formal tax report.
This matters because the most common objection to crypto tax software — "I paid for it and the number was wrong" — disappears when you can verify the number before paying.
The Practical Case for Fixing This Before April 15
The economics of this decision are not complicated.
A CPA who specializes in crypto charges between $50 and $400 per hour. For a user with thousands of transactions spanning multiple chains, a full manual reconciliation requires many hours. The bill frequently exceeds the tax liability itself.
The risk of filing with an incomplete cost basis picture is a phantom assessment — the same kind that generated the $85,000 notice described at the start of this piece. Resolving that assessment requires professional time, additional documentation, and in some cases amended returns. The cost of resolution is higher than the cost of prevention.
Koinly's paid plans are available at a fraction of either alternative. Through this link, new users receive 30% off their first tax report — the only time the platform is discounted. There is no price to reveal here, because the relevant comparison is not to a list price: it is to an accountant's hourly rate or to the cost of an IRS dispute you could have avoided.
The practical steps are straightforward. Create a free account. Connect your exchanges and wallets via read-only API — a process that typically takes minutes per platform, with step-by-step instructions for every major exchange. Allow Koinly to import your full transaction history, including all self-transfers. Review the capital gains preview the free plan provides. Verify that the numbers reflect your actual situation. If they do, purchase the plan that covers your transaction volume and download the report.
The formal output is whatever your jurisdiction requires: Form 8949 and Schedule D for US taxpayers, an HMRC Capital Gains Summary for UK residents, the ATO myTax report for Australian investors, CRA Schedule 3 for Canadians. For the 120 countries beyond those, a comprehensive report exportable in a format your local accountant can work with. TurboTax and H&R Block exports are available for US users who file through those platforms.
For users who want a human to confirm the work before filing, the Expert Review add-on provides exactly that.
The Exit
The investor in the case that opened this piece had their situation resolved. They could document their cost basis. The $85,000 assessment was corrected.
Not everyone in that situation can.
If the records from the platform where they originally bought the asset no longer exist — if the exchange has closed, if the CSV is gone, if the history was never exported before the account was deleted — the reconstruction becomes significantly harder, and in some cases impossible to complete in a form the IRS will accept.
The window for building a complete, defensible cost basis record is now, before the records become unavailable and before the assessments arrive.
Connect your wallets. See your number. Save 30% on your first report.
The link is below. The free plan is where you start.
For investors who have used more than one platform, moved assets, or participated in DeFi in any form: the cost of not checking this is not zero.
Click to Use Koinly: 30% off first tax report
This article reflects the author's independent analysis of publicly available information regarding cryptocurrency tax compliance. It does not constitute tax advice. Consult a qualified tax professional for advice specific to your situation. The author may receive a commission if you purchase a Koinly plan through the link above.
