Cost Basis
In financial accounting and tax law, cost basis (or acquisition cost) represents the original recognized monetary value assigned to an asset for tax calculation purposes. When a crypto-asset is eventually sold, exchanged, or otherwise disposed of, its cost basis is deducted from the gross disposal proceeds to determine the resulting capital gain or capital loss.
Core determination of cost basis
The cost basis of a crypto-asset is established at the exact moment of acquisition:
- Purchases for fiat currency: The cost basis equals the fiat amount paid to acquire the asset (e.g. EUR, USD), including any direct purchase fees or brokerage costs recognized by the applicable tax jurisdiction.
- Crypto-to-crypto acquisitions: When asset B is acquired by swapping asset A, the cost basis of asset B is generally set to the fair market value of the transacted assets on the trade date.
- Earned tokens (staking, mining, airdrops): Tokens received as income or service compensation generally establish an initial cost basis equal to their market value at the time of receipt.
| Acquisition Scenario | Basis Determination Rule |
|---|---|
| Direct Fiat Purchase | Total purchase consideration paid (in legal tender) |
| Crypto-to-Crypto Swap | Fair market value of the consideration given/received at time of trade |
| Inheritance | Stepped-up basis equal to the fair market value of the assets on the date of succession |
| Gift (Inter Vivos) | Carryover basis transferring the original acquisition cost of the donor |
| Missing / Unproven Records | Statutory presumption of zero cost basis, rendering 100% of proceeds taxable |
The zero cost basis presumption
A fundamental principle across tax jurisdictions is that the burden of proof for substantiating cost basis rests entirely with the taxpayer. If a taxpayer cannot produce auditable records (such as complete exchange transaction histories, banking withdrawal slips, and blockchain wallet logs) proving the historical purchase price of an asset, tax authorities are statutorily empowered to assume a zero cost basis.
Under a zero cost basis, the entire gross disposal consideration is treated as taxable net profit, resulting in substantially higher tax liabilities.
Cost basis tracking and inventory methods
Because cryptocurrencies of the same type are fungible, acquiring multiple parcels of an asset over time creates distinct "tax lots" with varying cost bases. When a partial disposal occurs, the recognized cost basis is identified through an accounting method:
- LIFO (Last In, First Out): Deducts the cost basis of the most recently acquired units.
- FIFO (First In, First Out): Deducts the cost basis of the oldest acquired units.
- Average Cost Basis (ACB / WAC): Blends the cost basis across all held units into a uniform weighted average.
For practical calculation and tax declaration rules in specific jurisdictions (for example, under Italian tax residency), see our dedicated guides on Calculating Capital Gains and Cost Basis and the Italian Crypto Tax Return Guide.
The information in this article is for general literacy only. It is not tax, legal, financial, or accounting advice and does not replace Agenzia delle Entrate instructions or advice from a qualified professional for your circumstances. It must not be used to evade tax obligations. We make no warranty as to accuracy, completeness, or currency; rules and practice can change. Do not file returns or make decisions based solely on this text. RIXTO is not liable for loss arising from use of, or reliance on, this information.