Internet Computer (ICP): neurons, NNS, and taxation for Spanish investors

Internet Computer is a project by DFINITY aiming to be a "decentralized internet" where applications run directly on the blockchain without cloud intermediaries (AWS, Azure). Its ICP token and the neuron system for governance create a unique staking mechanism with specific tax implications.

The Network Nervous System (NNS): on-chain governance

The NNS is the governance system of the Internet Computer. To participate:

1. Lock ICP in a neuron: the neuron can be locked for periods ranging from 6 months to 8 years.
2. The neuron votes on network proposals (either automatically by following "follow neurons" or manually).
3. Earn voting rewards in ICP proportional to:
   • The amount of ICP locked.
   • The lock-up period (the longer the period, the higher the multiplier: up to 2× for the maximum of 8 years).
   • Voting activity (if your neuron actively votes, not just delegating).

What are voting rewards?

Voting rewards are the inflationary issuance of ICP distributed among those participating in governance through neurons. The APY can vary from 5% to 20% depending on the dissolve delay (lock-up period) and the global participation rate.

Neuron maturity:

• Rewards accumulate as the "maturity" of the neuron, not directly as ICP.
• To convert maturity into ICP, you must "spawn" (create a new neuron from the maturity) and then dissolve that new neuron.
• The process can take an additional 7 days.

Taxation of neuron staking

Taxable event timing: accumulation or distribution?

Option A: Tax when spawning and receiving ICP

• The taxable event occurs when you materialize the maturity into ICP.
• You only pay taxes when you spawn and dissolve the resulting neuron.
• This is more favorable for deferring taxes.

Option B: Tax on maturity accumulation

• Accumulated maturity is considered implicit income.
• The AEAT could treat it as accrued interest from a bond.
• This is more conservative but more complex to calculate.

Without specific DGT guidance on ICP, Option A seems the most reasonable due to its analogy with accumulation funds or Compound's cTokens.

Classification of income

• Investment income: analogous to interest and capital returns.
• Business income: if you manage multiple neurons actively.
• For most individual investors: investment income.

The dissolve delay and ICP lock-up

When you lock ICP in a neuron:

• The locked ICP cannot be withdrawn until the dissolve delay expires (from 6 months to 8 years).
• During this time, the ICP remains yours → it is not considered a transfer.
• If the ICP increases in value while locked → the latent capital gain is not taxed until it is sold.

Dissolution of the neuron

When the neuron dissolves and you receive the ICP:

• You receive the original ICP + the ICP from the rewards earned.
• The original ICP → retains its original acquisition cost.
• The ICP from rewards → new asset with an acquisition cost = EUR value at the time of spawn.

ICP for paying cycles (compute fees)

Developers deploying applications on Internet Computer pay with "cycles" (generated by burning ICP):

• Burning ICP to obtain cycles → transfer of ICP at market price.
• Capital gain/loss: difference between the acquisition cost of the burned ICP and its value at the time of burning.

SNS (System Nervous Systems) of dApps

Many applications on Internet Computer have their own decentralized governance systems (SNS):

• Each SNS has its own token (e.g., SNS-1, OpenChat token, etc.).
• Participating in the SNS with stakes and voting rewards works the same way as the NNS.
• The SNS token may have an external market (listed on exchanges) → taxation is the same as for ICP.

SNS token airdrops

NNS participants sometimes receive SNS token airdrops:

• SNS token airdrop to NNS neurons → taxable income under general base at market value.
• If the token does not yet have a market price → reasonable estimated value or 0 (and taxable event at the time of first sale).

ICP taxation table

Updated: April 2026 | Tax year: 2025