A year-end crypto tax file is easier to work with when every swap has five linked facts: date, tokens, quantity, value, and a transaction record. If you are preparing for your first filing, start by collecting the activity rather than trying to calculate tax from memory.
Build one record for every swap
For each transaction, write down when it happened, which tokens went out and came in, how many units changed hands, and their value in your tax currency at that time. Add the wallet address, transaction signature (the transaction’s unique on-chain reference), and any fee paid. Save the original export or a copy of the transaction details as evidence.
Use the blockchain timestamp and note the time zone; then convert the value into the currency your tax authority requires. Keep the price source and method with the record, especially if token prices differ across markets. HMRC’s record-keeping guidance asks UK taxpayers to retain the transaction date, asset type, units, sterling value, and wallet details; the IRS likewise calls for records supporting digital-asset transactions and their fair market values. HMRC’s cryptoasset record-keeping guidance and the IRS digital-asset FAQs show why a transaction reference alone is not the whole record.
For a Solana swap you need to document, Byreal is a decentralized exchange where you can exchange tokens; keep the transaction signature and your own notes with the trade details. The on-chain record can help show what moved, while your notes connect that activity to you and explain the values you used. Do not assume that a wallet history will preserve every price or tax detail you need.
Trace the swap from the tokens you spent to the tokens you received
A token-for-token swap may count as a disposal of the token you gave up, even though no cash reached your bank; the exact tax result depends on your country’s rules. Treat the outgoing token as one side of the record and the incoming token as the other, so you can later match the outgoing asset to its acquisition cost, often called its cost basis.
For example, suppose you acquired 1 SOL for £100 and later swap 0.4 SOL for 12 units of another token. If the 0.4 SOL is worth £60 at the time of the swap, record £60 as its value and preserve the records showing how much it cost you to acquire that 0.4 SOL. If its attributable cost were £40, the simple difference would be £20 before applicable fees and local rules. These figures are illustrative, not a tax calculation.
The incoming token needs its own acquisition record too: 12 units, the swap date, and the value used for the exchange. That value may become relevant if you later sell or swap those tokens. Keep full precision in your raw data; rounding every trade to whole pounds or dollars can create a noticeable difference across many transactions.
Keep fees, transfers, and liquidity activity distinct
Record fees separately from the amount swapped, and note which asset paid each fee. A network fee, for example, may be paid in SOL, while a trading charge could be deducted from one of the exchanged tokens. Paying a fee in crypto can itself have tax consequences in some jurisdictions, so preserve the fee amount, token, time, and value instead of silently folding it into the swap total.
A transfer between wallets you own is different from a swap because you have not necessarily exchanged one asset for another. Label it as an own-wallet transfer and keep both wallet addresses and the matching transaction references; otherwise, tracking software may mistake it for a sale or an unexplained deposit. If you provide liquidity, record each deposit, withdrawal, reward, and any token amounts returned. Their tax treatment can be less straightforward than a simple swap, so do not collapse them into one trade.
Byreal’s role is the on-chain exchange; your records should also account for what happened before and after that exchange. Keep a transaction log alongside wallet exports so that a later reviewer can follow the flow from acquisition, through the swap, to any later disposal. This is useful even if you use tax software, since imported transactions can still need labels or corrections.
Reconcile the year before preparing a return
At year-end, gather records from every wallet and service you used, then compare them against the transaction log. For each entry, check that the outgoing amount, incoming amount, fee, timestamp, and transaction signature agree with the on-chain activity. Mark unexplained transfers for investigation instead of deleting them or guessing.
A common edge case is a failed or partially completed transaction: a signature may exist even when the intended swap did not happen, while a network fee may still have been charged. Check the actual token movements rather than treating every submitted transaction as a completed trade. Save the evidence and make a note of what you concluded.
Keep the raw exports, valuation notes, and corrected log together, with a backup you can still access later. Retention periods and tax treatment vary by country, so check your local authority’s current rules or ask a qualified tax professional how to report a particular DeFi event. Your next step is to export your wallet activity now, make a row for every swap, and fill in missing prices and fee details while the records are easy to verify.