The common ones are missing cost basis, wallet-to-wallet transfers recorded as sales, staking and airdrop receipts never valued when they arrived, and records that cannot be split by wallet. They share a shape: each is a fact that was free to capture on the day and costs real money to reconstruct years later. In my experience, when a record was written predicts its quality better than how carefully.
Part of our guide: Crypto Taxes.
The short version
- The IRS treats digital assets as property for U.S. tax purposes (IRS), so every disposition needs a basis and a holding period that survive years.
- The costliest omission is cost basis captured at acquisition. Everything else here rebuilds at some price.
- Moving your own coins between your own wallets creates no taxable event, and a record omitting the connection turns it into one on paper.
- Basis conventions apply account by account, so each wallet carries its own lots (26 U.S.C. § 1012(c)(1)).
- From 2026 these gaps stop being private: brokers report basis on certain transactions, so your number and theirs can now disagree in public.
At acquisition: the number nobody writes down
Cost basis is knowable to the cent on the day an asset arrives and gets harder every month afterward. That asymmetry is the whole subject. Publication 551 states the obligation plainly: “You must keep accurate records of all items that affect the basis of property so you can make these computations.” The IRS asks digital asset holders for records that “document your purchase, receipt, sale, exchange or any other disposition.”
At acquisition that is short: date and time, quantity at full precision, dollar cost including fees, the venue or address involved, and the price source where it was bought with something other than dollars. A venue’s transaction history is a copy you do not control, so take yours while the account is open.
Two categories get skipped almost universally. Anything that arrived without a purchase, such as mining and staking output, airdrops, forks, and payment for work, takes basis at fair market value on receipt, the only moment that value is observable. Anything received by gift or inheritance carries different basis rules, and its history exists only with the person who transferred it.
During the year: the events that do not feel like events
Most gaps open here, because the transactions that create them do not feel like transactions.
Transfers between your own wallets. No taxable event occurs, and the record still has to say so. With nothing connecting the outflow at one address to the inflow at another, reconstruction software reads the halves as a sale followed by a purchase: a gain that never happened, beside a basis figure invented at import.
Rewards and receipts. Staking rewards become income at the point the taxpayer gains dominion and control, valued as of that point (Rev. Rul. 2023-14). Airdrops, forks, and payment in kind follow the same logic, each receipt a separate event carrying its own date, value, and basis going forward. Totaling a year of them at one price is the most common shortcut here, and it damages the income figure and every later disposition. Whether an entity should generate that stream is a separate question.
Spending. Paying a vendor in stablecoins is a disposition even where the gain rounds to nothing, and network fees paid in the native token are dispositions nobody records.
Ownership. Where an entity or a trust holds the wallet, the record names which one at the time of the transaction, because splitting personal from company activity a year later, from a single address, is guesswork. Wallet ownership by an LLC settles title, and the entity’s classification settles the return.
At disposition: the mistakes someone else can now see
A weak record used to be a private problem, surfacing only under examination. That is changing on a published schedule.
Which units you sold, and what they cost, attach at the account level:
“In the case of the sale, exchange, or other disposition of a specified security on or after the applicable date, the conventions prescribed by regulations under this section shall be applied on an account by account basis.”
For digital assets that means wallet by wallet. Revenue Procedure 2024-28 opened a safe harbor, resting on section 1012(c)(1) and Treas. Reg. § 1.1012-1(j), for allocating unused basis across wallets and accounts as of January 1, 2025. Anyone who skipped it is attaching lots to wallets by an assumption that exists nowhere in writing.
Identification is the other half. Notice 2026-20 carries the temporary identification relief of Notice 2025-7 forward through December 31, 2026, and its limit is the part people miss: the relief reaches units a broker holds in custody. Self-custodied units fall outside it. A hardware wallet draws no relief and no statement, so the identification has to sit in the owner’s file, made at or before the disposition.
Then the visibility. Broker reporting arrives in two stages: gross proceeds on transactions from Jan. 1, 2025 onward, and basis on certain transactions from Jan. 1, 2026 onward (IRS), both carried on Form 1099-DA. Your figure and the broker’s now reach the IRS together, and Form 8949 exists to “reconcile amounts that were reported to you and the IRS on Form 1099-B or 1099-S (or substitute statement) with the amounts you report on your return.”
My view is that this is the real change in the cost curve. A basis gap used to become expensive whenever you sold. It now also creates a discrepancy on a document somebody else filed, and those get resolved by people whose default assumptions are not yours.
What I actually see
The file that starts at the wrong year. People begin tracking in the year they first sold something, because that is the year tax became interesting. Everything earlier is a hole, and those older lots carry the largest embedded gain.
The transfer counted twice. Software pulls history from three venues and a hardware wallet, and the same coins appear as an outflow at one and an acquisition at another. The year then contains a disposition that never occurred and a cost figure nobody chose, surfacing as a gain far larger than the position could have produced.
The self-custody assumption. People read the broker rules and conclude they are covered. Notice 2026-20 reaches broker-held units only, and a hardware wallet sits outside that boundary: no statement arrives, no relief applies, and the evidentiary burden stays with the owner.
The check I would run before filing season takes fifteen minutes. Take your largest position and, without opening any software, produce the acquisition record for its oldest lot from documents you already hold: date, quantity, dollar cost, and where that evidence lives today. If you cannot, that is the exposure, because basis you cannot substantiate is basis you may not get to use.
Where this goes wrong
The file gets assembled at filing time, from software, out of whatever the venues still hand over.
The failures are consistent. A wallet migration that produced six on-chain transfers, all imported as fresh acquisitions at market. Staking output summed for the year rather than valued at each receipt. An entity formed in June with company transactions still running through a personal account until October. A Rev. Proc. 2024-28 allocation never made, so every lot sits in a wallet by assertion. And a preparer who inherits all of it in March with no way to test a single figure.
The decision rule
- Capture basis at acquisition: date, time, quantity at full precision, dollar cost, and fees.
- Take your own copy of every venue statement while the account is open.
- Label every wallet-to-wallet transfer as a transfer at the time, naming both addresses.
- Value each reward, airdrop, fork, and payment on the day it arrives, from one named price source.
- Track basis by wallet and by account, because § 1012(c)(1) applies the conventions that way.
- Make the identification at or before the disposition, since the relief in Notice 2026-20 does not reach self-custodied units.
- Reconcile your figures against each Form 1099-DA before filing, which is the job Form 8949 was built for.
- Name the owner of every wallet in the record, so entity and personal activity never have to be split from memory.
Where this sits
Records are the layer every earlier decision gets read through. Which return the activity reaches belongs to tax reporting for LLCs, and whether any evidence exists to produce belongs to custody. Trusts and estate planning decide who produces it once you cannot, which is when the same omissions cost the most, since whoever reconstructs them never saw a transaction.
None of this sits inside one profession. Basis is a tax fact, ownership is a legal fact, and possession is an operational fact, usually held by three people who never compare notes. The join is what fails: the CPA prepares from a file nobody else has read, the attorney’s documents assume assets whose location was never confirmed, and the operational record lives with whoever holds the keys. Your record has to be true in all three places at once, which is the argument for one person reading all of it annually.
Sources
- IRS, Digital assets
- IRS, Publication 551, Basis of Assets
- 26 U.S.C. § 1012, Basis of property (cost) (Cornell Legal Information Institute)
- IRS, Revenue Procedure 2024-28, digital asset basis allocation safe harbor
- IRS, Notice 2026-20, extension of temporary identification relief
- IRS, About Form 1099-DA, Digital Asset Proceeds From Broker Transactions
- IRS, About Form 8949, Sales and other Dispositions of Capital Assets
Related
- Crypto tax reporting for LLCs
- Common crypto estate planning mistakes
- Can a Wyoming LLC stake crypto?
- Crypto estate data room checklist
- Can an LLC hold stablecoins?
- Crypto tax and records
Last updated: 3 August 2026.
This article is general education, not legal, tax, or investment advice. Basis, holding period, and reporting outcomes depend on your own transaction history and the records you can substantiate. Talk to a qualified CPA about your own situation.
