Payments
Self-custody and taxes: simpler with the right records
Learn how tax software imports wallet activity, why cost basis matters, and how to organize Lex records without giving anyone control of your assets.
Can tax software make self-custody easier?
Yes. Software can reduce the bookkeeping involved in a self-custodial wallet by bringing transactions into one place. A public wallet address gives a compatible service a way to read blockchain activity without taking control of the assets. The practical goal is a complete, understandable record that you can review before filing.
The useful promise is less manual work, not a guaranteed correct return from one click. Software still needs to know where assets came from, what you paid, and why a payment happened. An incoming transfer might be salary, a gift, a purchase, or money moved from your other wallet. The blockchain alone does not explain that context.
Start with the software’s country coverage, supported networks, and reporting options. A service that imports your tokens may still lack the forms or asset classifications your situation requires. This guide explains recordkeeping; local tax rules determine the result.
Which transactions need attention?
For a U.S. taxpayer, the IRS distinguishes holding assets from selling, exchanging, or spending them. Payment for work can create income. Stablecoins are included in its digital asset guidance: a stable price does not remove reporting questions. These are U.S. examples, not rules to apply automatically in another country.
The IRS also says a transfer between wallets you own is generally non-taxable, while digital assets used to pay the transfer fee can have separate consequences. A transfer to a friend, a swap, or a deposit into a protocol is not automatically the same situation. Record the purpose before choosing a category.
Think in events rather than account balances. A year-end balance cannot explain whether you earned money, sold an investment, or simply moved it. Keeping those events connected is where software becomes useful.
A practical software workflow
Koinly is one example of a service with a documented Base wallet import. You add the public address under the correct blockchain and let the service retrieve the activity it supports. That is different from connecting a wallet to sign transactions. No private key, recovery phrase, or passkey should be needed for this address-based import.
Then add the other wallets and exchanges you used, including older accounts with purchases that explain assets you still hold. Select your reporting country, currency, and tax year. Check the available report before paying for a plan; importing transactions and producing a suitable tax filing are separate capabilities.
Read-only access still has a privacy consequence: the service can associate an address and its history with your account. Review its permissions and data policy, and share records deliberately. Software compatibility is not a Lex partnership or a guarantee that every token will be classified correctly.
Using your Lex wallet records
Lex uses Turnkey for the wallet infrastructure described in our self-custody guide. For tax preparation, the useful starting point is your public wallet address. You do not need to export the private key or change who controls the wallet to let compatible software read its public history.
In Lex’s Receive flow, copy the wallet address and confirm the Base network. Use the address itself in the tax tool, rather than the QR image or payment-request link. In Activity, open relevant transactions and compare the status and available details with the blockchain explorer. Keep bank and exchange receipts alongside these records.
A blockchain import cannot establish the original bank purchase price for every incoming token. It also may not explain a payout into pesos or reais. Treat the wallet history and those receipts as complementary records, and review missing information before calling the file complete.
An example: moving money does not erase its purchase history
Imagine a U.S. taxpayer buys 600 USDC for US$600, with no fees in this simplified example. They move 400 USDC to another wallet they own. Later they sell 200 of those tokens for US$201. Assume one purchase lot and no other transactions, so there is no ambiguity about which units were sold.
The records should connect the original purchase, the transfer out, the transfer in, and the sale. The 200 tokens sold have an illustrative US$200 purchase cost, giving a US$1 difference before any applicable adjustments. The remaining 400 USDC are spread across the two wallets. These are accounting examples, not prices offered by Lex.
Importing only the receiving wallet hides the purchase. Koinly documents how it matches transfers between your own wallets. Check that the pair was matched and that the acquisition history followed the tokens. Correcting the source records is more useful than accepting an unexplained profit figure.
Keep a small set of supporting records
Keep a folder for each tax year with bank statements, exchange purchase records, payment receipts, and notes explaining unusual transfers. A wallet address is a useful index to blockchain activity, but an invoice or original purchase confirmation may answer a different question: why the money arrived or what you actually paid.
HMRC’s recordkeeping guidance is one example of an authority explaining what transaction evidence matters. Whatever your jurisdiction, make the records easy to compare. Preserve original documents, identify the account they cover, and note the time zone. If you correct an imported entry, keep a short explanation and the supporting document together.
Distinguish confirmed amounts from quotes and unknown values from zero. A bank deposit and the corresponding token receipt may describe one funding operation. Keep their references connected so they are not counted as two independent sources of income. You can share the relevant records with an accountant when a manual review is needed.
| Record | Why it helps |
|---|---|
| Date, time, and time zone | Match activity across different services. |
| Assets and quantities sent and received | Reconstruct both sides of a transfer or trade. |
| Fees, original currency, and receipts | Investigate costs without inventing a valuation. |
| Wallet, network, status, and transaction reference | Check ownership, completion, and duplicates. |
What still needs a human check?
Resolve warnings before trusting totals. Missing purchase history can cause software to assume a zero acquisition cost and overstate a gain. Check earlier years, missing accounts, duplicate imports, and timestamps. Preserve the evidence behind any correction instead of changing numbers merely to make a warning disappear.
Give more attention to unfamiliar assets and complex activity. Tokenized stocks, vault positions, rewards, and DeFi exchanges can require classification beyond recognizing a token symbol. If an amount is only an estimate or a transaction failed, do not quietly treat it as a completed sale at that value.
A short monthly review is easier than reconstructing a year from memory. Reconcile balances, label unexplained transfers, and store receipts securely. Before filing, ask a qualified local adviser about unresolved classifications, substantial amounts, or activity spanning countries.
Your tax residence matters more than the app’s language
Choose guidance for your own obligations. HMRC explains UK disposals and records; Brazil’s Receita Federal maintains cryptoasset reporting guidance, including DeCripto materials. Argentina’s ARCA addresses cryptoassets under Bienes Personales. Income tax and information or asset declarations can be separate questions.
A Spanish interface does not mean Spanish law applies, and a dollar-linked token does not make someone a U.S. taxpayer. If you report in reais, pesos, or another currency, retain the relevant original amounts and valuation evidence. A price stable in dollars can still change when expressed in that currency.
With the right imports and a regular review, self-custody can fit an ordinary recordkeeping routine. Keep control of the wallet, give software the information it needs, and use local expertise for decisions the records alone cannot settle.