Rebuilding crypto records and cost basis, including coins bought before moving

Key rules

• Pre-arrival coins: Coins bought before you moved keep their original cost; arriving in Spain does not reset it.
• Burden of proof: You must prove what you paid, and with no proof the whole sale price can be treated as gain.
• Own-wallet moves: Moving crypto between your own wallets is not taxable, but keep the transfer records.
• Price source: Use one consistent, recognised price source and save a dated screenshot for each valuation.

The short version

You must be able to prove what you paid for each coin. Missing proof is the biggest risk: without it, the tax office can set its own value, and the whole sale price can be treated as gain. Build the records now, before you sell.

Coins you bought before moving

Coins bought before you became a Spanish tax resident keep their original cost: the price you paid plus fees. There is no reset to market value on the day you arrive. If you sell later as a resident, your gain is the sale price minus that original cost, and it is taxed as savings income.

If you are under the Beckham regime, only Spanish-source income is taxed, so foreign crypto gains are generally outside Spanish tax. Some gains still count as Spanish-source, for example sales through Spanish-resident entities. The regime does not reset your cost basis either. Check your case with a Spanish tax adviser.

What counts as proof

The burden is on you. The tax office accepts any valid proof. The strongest are:

• Exchange statements and full transaction histories.
• Trade confirmations and invoices.
• Bank transfers or card statements showing euro purchases.
• Wallet and blockchain records.
• Contracts.

Your own spreadsheets and crypto tax tool reports are accepted as support, but only if they match those primary documents. The tax office can also cross-check what you declare against data it receives from banks, exchanges and foreign-asset filings. The documents list below has the full set.

Rebuild the history step by step

1. Download full histories from every exchange you have ever used, now. Old accounts can close and data can disappear.
2. List every wallet address you have used, and match each transfer between them with the same date, amount and fee.
3. Match each purchase to a bank or card record in your home currency.
4. Order everything by date, per coin, across all wallets and exchanges together. Gains are then matched first-in first-out for each cryptocurrency.
5. Save the result with the source files beside it.

Moves, swaps and fees

Moving crypto between your own wallets or exchanges is not taxable, because ownership does not change. Keep the date, addresses, amounts and fees to show that the coins in each lot are the same coins. A network fee paid in crypto can count as a small disposal, or as a cost, depending on the case.

Swapping one crypto for another, including a stablecoin, or spending crypto on goods is a taxable disposal. Balances held abroad may also need a separate declaration.

Valuing coins on a given date

The rule is market value on the date of the event, and you must be able to justify it. No single official price source is required. Use the price on the exchange where you traded, or a recognised price aggregator, and use the same source consistently. Record the date and time, and keep a screenshot or export.

For the foreign-asset declaration, the 31 December value comes from the custodian's statement or the average price of the last quarter. For wealth tax, the Ministry of Finance publishes year-end values for the main coins only.

If you cannot document your cost

The tax office may estimate the value from other evidence it has. If no purchase cost is shown, the whole sale price is treated as gain, which is the same as a cost of zero. Savings income is taxed on a progressive scale; for 2025 it ranged from 19% to 30%.

To reduce the damage:

• Ask exchanges for old histories, and use bank records and blockchain data.
• Where gaps remain, make a reasoned estimate based on market prices on the purchase date, and write down how you reached it.
• File with a short explanation if needed.

The "What if" section below covers lost histories and unreported crypto.

Documents you need

• Exchange statements and full transaction histories, downloaded from each exchange you have used.

• Trade confirmations and invoices for each purchase.

• Bank transfer records or card statements showing the euro purchases of crypto.

• Wallet and blockchain transaction records showing dates, addresses, amounts and fees for every transfer between your own wallets.

• Contracts for any crypto bought or sold under a written agreement.

• Your own accounting records and reports from crypto tax tools. They only support your case if they match the documents above.

• Screenshots or exports of the price source you used for each valuation, showing date and time.

What if you lost exchange history or never reported crypto?

You can fix this, but act before Hacienda contacts you

Missing exchange history or unreported crypto can usually be put right. Rebuild the records as well as you can, then file a late or complementary return for each affected year and pay the surcharge. This works only while the four-year limitation period is still open, and only if Hacienda has not already sent you a requirement.

Rebuild the history first

Work in this order:

1. Ask every exchange you used, including closed accounts, for your full transaction history and annual tax reports. If support is slow, send a data-protection access request.
2. Use bank and card statements to prove your euro deposits and purchases.
3. Trace your wallet addresses on a block explorer for on-chain transfers. Import everything into crypto tax software that supports Spain's first-in first-out method. The matching rule is explained in the records and basis guidance.
4. Add old email confirmations and CSV exports.

If gaps remain, write a short explanation of what is missing and how you estimated it. Base any estimate on market prices on the purchase date.

Why gaps cost you money

If you cannot document what you paid, Hacienda can estimate the value from other evidence. If no purchase cost is shown, the whole sale amount counts as gain, which is the same as a zero cost. Savings income is taxed on a sliding scale, and for 2025 it ran from 19% to 30%. A reasoned, documented estimate is better than leaving the cost blank.

File late or file a complementary return

• If you never reported a year, file a late voluntary return (declaración extemporánea) for that year.
• If you reported but got it wrong, file a complementary return for the same year.

Either way, you pay a surcharge (recargo). It rises with each full month of delay, starting at 1%. After 12 months it is 15% plus late interest. Paying promptly cuts the surcharge by 25%.

This route works only if you file before Hacienda sends you a requirement. If you already have one, the surcharge no longer applies and penalties follow, so speak to a tax adviser straight away.

Foreign crypto and Modelo 721

If you left out Modelo 721 (the declaration of crypto held abroad), you can still file it late. The old fixed penalties were found to breach EU law, and late filings now fall under the general penalty rules, which are lighter. Check the current penalty text with a tax adviser, as it may still be changing.

Check the time limit

Hacienda can review a tax year for four years after the voluntary filing period ends. For the 2022 income tax return, filed in mid-2023, that period ends in June 2027. The clock restarts if Hacienda acts to assess the debt, if you appeal, or if you acknowledge the debt. The same four-year limit now applies to Modelo 721.

Frequently asked questions

Which price source can I use to value crypto on the date of a sale?

No single official price source is required, so use the price from the exchange where you traded or a recognised aggregator such as CoinMarketCap or CoinGecko. Use the same source every time and note the date and time. Keep a screenshot or export of each price, because you must be able to justify the value.

Do coins I bought before moving to Spain get a new cost basis when I arrive?

No, coins bought before you became a Spanish tax resident keep their original cost, meaning the price you paid plus fees. There is no step-up to market value on arrival.

What happens if I cannot document what I paid for my crypto?

If you cannot show your cost, Hacienda may estimate it, and the whole sale amount can be treated as gain. For 2025, savings income was taxed on a scale from 19% to 30%. Rebuild the history from exchange requests, bank records and blockchain data, or use a reasoned estimate backed by market prices on the purchase date.

Does the Beckham regime reset my crypto cost basis?

No, the Beckham regime (the special regime for inbound workers) does not reset your cost basis.