Matic/Polygon: Layer 2 of Ethereum and taxation in Spain
Polygon (formerly known as Matic Network) is the most widely used Ethereum scaling solution. With pennies commissions and full EVM compatibility, it hosts a massive DeFi and NFT ecosystem. In 2023, MATIC migrated to POL as a native token.
MATIC → POL: token migration
In 2023-2024, Polygon migrated from MATIC to POL as a native token. MATIC holders were able to exchange their tokens for POL in a 1:1 ratio.
Does this exchange generate a tax event?
This is the key question:
- If it is considered a transmission (MATIC deliveries, you receive POL): it would have become taxable.
- If an internal restructuring of the same asset is considered (upgrade): there would be no tax event.
The DGT did not publish specific criteria on this migration. The majority criterion among advisors is that, given that the economic value is maintained and it is an update of the protocol, it could not be considered transmission. However, when in doubt, it is prudent to record it and consult with an advisor.
POL Staking
The POL can be staked to secure the Polygon network:
- Staking rewards → return on capital upon receipt.
- Approximate APY: 4-8% in POL.
Staking can be done directly or through delegated staking services.
DeFi on Polygon: QuickSwap, Aave, Curve
Polygon's main DeFi protocols are treated the same as their Ethereum equivalents:
- QuickSwap (DEX): Each swap is a transmission → capital gain/loss.
- Aave on Polygon: Loans and interest. Interest → movable capital.
- Curve in Polygon: Liquidity pools. Same treatment as Curve on Ethereum.
Gas commissions at Polygon are paid in POL (or MATIC before), and are deductible as the cost of each operation.
##Bridges Ethereum ↔ Polygon
The Polygon PoS Bridge allows assets to be moved between Ethereum and Polygon:
- You deposit ETH/ERC-20 in the Ethereum bridge → the bridge gives you the equivalent in Polygon.
- You withdraw from Polygon → recover in Ethereum.
Tax treatment of bridges:
- Moving assets yours between networks without change of ownership: It is not a taxable event in principle.
- But the AEAT does not have clear criteria and some advisors recommend registering it as a transmission.
- The fundamental thing: maintain the record to be able to demonstrate that the funds are the same.
NFTs on Polygon
The NFT market on Polygon (OpenSea support Polygon, etc.) is very active due to its low commissions:
- Buy NFT with MATIC/POL: token transmission → possible profit/loss.
- Sell NFT: capital gain/loss.
- Mintear NFT: gas cost deductible from the sale price when you sell.
Zkevms: Polygon zkEVM
Polygon launched its zkEVM, an EVM-compatible ZK-rollup solution. Fiscally, transactions on your zkEVM have the same treatment as on the main chain.
Operation log in Polygon
- PolygonScan: Official explorer. You can export the transaction history of a wallet.
- Zapper/DeBank: Multi-chain DeFi activity aggregators including Polygon.
- declaracrypto.es: Automatic import of Polygon history.
Updated: April 2026 | Fiscal year: 2025