IOTA and Shimmer: Taxation of the Tangle and DAG Staking

IOTA is a distributed ledger project that does not use conventional blockchain but rather a directed acyclic graph (DAG) structure called "Tangle." Instead of miners or validators, each user sending a transaction must validate two previous transactions. The result: feeless transactions and a scalable architecture for IoT.

MIOTA vs. SMR: Two Tokens, Two Networks

MIOTA (IOTA)

• Native token of the main Tangle network.
• Currently evolving toward IOTA 2.0 (Coordicide: removal of the centralized coordinator).
• MIOTA staking: the MIOTA staking period to receive SMR tokens occurred in 2021-2022.

SMR (Shimmer)

• Incentivized pre-production network of IOTA (analogous to Kusama for Polkadot).
• MIOTA holders who participated in the 2021-2022 staking received SMR as a reward.
• Shimmer has its own DeFi ecosystem (ShimmerEVM, ShimmerSea AMM protocol).

Taxation of MIOTA Staking to Receive SMR

The historical MIOTA staking event to receive SMR (October 2021 - January 2022):

• Users locked MIOTA in the IOTA app for 90 days.
• They received SMR proportionally: 1 MIOTA → 1 SMR.

Tax Treatment:

• Locking MIOTA → not a transfer (you remain the owner).
• Receiving SMR → considered a "staking reward/airdrop."
• Investment income: SMR's value in EUR at the time of receipt.
• If SMR had no market price at the time of receipt (as it was its launch) → initial valuation at €0, capital gain/loss (GPO) upon first sale.
• Once SMR was listed → acquisition cost is the EUR value at the time of effective receipt.

ShimmerEVM and DeFi in IOTA/Shimmer

With the arrival of ShimmerEVM (EVM-compatible) and Shimmer's DeFi section:

• Swapping SMR for other tokens on ShimmerSea or TangleSwap → constitutes a transfer of SMR → GPO if there is a gain.
• Liquidity provision → same as any AMM:
  • Deposit: potential GPO or not, depending on whether the LP token is taxed as a new asset.
  • Trading fee rewards: investment income (RCM).
  • Withdrawal: GPO if the LP token's value changes compared to acquisition cost.

Native Staking in IOTA 2.0 (Coordicide)

With IOTA 2.0, a validator system with native MIOTA staking will be implemented:

• Validators will earn rewards in MIOTA.
• Tax treatment will be analogous to Ethereum staking: investment income (RCM) for received rewards.

Feeless Transactions and Taxation

A unique feature of IOTA is that transactions are feeless. This means:

• No deductible expense for network fees when sending MIOTA.
• The cost of each transaction in EUR is €0 in terms of fees.
• Costs only apply in terms of the asset's price being transferred.

Compared to Ethereum (where gas fees must be recorded as acquisition or transfer expenses), IOTA's accounting is simpler.

Modelo 172 and IOTA

If you hold MIOTA or SMR in Spanish exchanges or exchanges with a presence in Spain:

• Exchanges licensed/present in Spain must report balances and operations to Modelo 172.
• If the exchange does not have a presence in Spain (e.g., many IOTA exchanges are smaller) → there may not be automatic reporting, but the obligation to declare remains with the taxpayer.

Tax Summary for IOTA/Shimmer

Updated: April 2026 | Fiscal Year: 2025