USDC, DAI, USDT and PYUSD: do they have the same tax treatment?

For the AEAT, all stablecoins are "virtual currencies" and are essentially taxed the same. However, the structural differences between them can generate important nuances in the daily tax practice of the Spanish investor.

Features compared

The common principle: they are virtual currencies

For the AEAT, no stablecoin is "money" in the legal sense (it is not legal tender in Spain).

Consequences:

• Each conversion from EUR to USDC is a purchase of an asset.
• Each conversion from USDC to EUR is a transfer of the asset → GPO if the exchange rate changed.
• Every change from USDC to USDT or DAI is a swap between assets → also potential GPO.

Profit/loss on stablecoins: the effect of the EUR/USD exchange rate

Stablecoins are pegged in dollars ($), not euros. When EUR/USD fluctuates, even though the stablecoin "holds" its $1 peg:

• USDC is still worth $1.
• But if the EUR/USD goes from 1.10 to 1.20 → 1 USDC was worth €0.909 and is now worth €0.833 → loss in euros although the USDC maintained its peg.

Tax example:

• You purchase 10,000 USDC when EUR/USD = 1.10 → cost: €9,090.90.
• You sell 10,000 USDC when EUR/USD = 1.20 → income: €8,333.33.
• Tax loss: €757.57 although the USDC "was worth the same".

Conversely, if the EUR depreciates (EUR/USD falls from 1.10 to 1.00):

• You purchase 10,000 USDC when EUR/USD = 1.10 → cost: €9,090.90.
• You sell when EUR/USD = 1.00 → income: €10,000.
• Tax profit: €909.10 without the USDC having "risen".

Difference between USDC and DAI in depegging risk

USDT and DAI have suffered depegs in the past:

• USDT in 2017: briefly traded at $0.92.
• DAI in the March 2020 crash: briefly traded at $1.11 (depeg up).
• USDC in March 2023: When Silicon Valley Bank went bankrupt, USDC briefly reached $0.87.

Fiscal when there is depeg:

• If you sold USDT at $0.92 → Negative GPO if you had paid more than $0.92.
• If you bought USDC at the time of depeg at $0.87 → acquisition cost in EUR is that reduced value.

DAI: the double fiscal layer of coining DAI

When you mint DAI by depositing ETH as collateral on Maker:

• There is no transmission of ETH (the ETH remains yours in the vault).
• The DAI received is debt, not income.
• By returning DAI → you recover ETH minus the interest paid (stability fee in DAI).

Fundamental difference vs buying USDC:

• USDC purchased: you acquire an asset with real cost in EUR.
• Minted DAI: there is no direct fiscal acquisition; The DAI is its own debt.

Conversion from DAI to USDS (Sky Migration)

When Maker launched Sky Protocol and converted DAI to USDS:

• If you had DAI and migrated it to USDS → DAI transmission:
  • Transmission price: value of USDS received (≈ $1 per USDS).
  • DAI acquisition cost: the one you had.
  • If you bought DAI for $1 → GPO ≈ 0. If you minted it (debt), the cost is more complex.

PYUSD: PayPal's stablecoin

PayPal USD (PYUSD) is backed by dollars and regulated under US banking laws. For the Spanish investor:

• Same tax treatment as USDC.
• Upon receiving PYUSD as payment → value in EUR at the time = acquisition cost.
• When selling → GPO.

Tax strategy: use stablecoins to "park" profits

Some investors sell BTC and buy USDC to "park" without exiting the euro. Considerations:

• The sale of BTC → GPO in the year of the sale.
• Holding USDC does not generate more GPO as long as USDC does not change value relative to the EUR.
• EUR/USD fluctuation can generate small additional GPOs when selling years later.

Summary table

Updated: April 2026 | Fiscal year: 2025