On 22 May 2010 at 18:16 UTC, a Bitcoin transaction moved 10,000 bitcoins to pay for two pizzas. Open that transaction on mempool.space today and it reads as if it happened this morning: 131 inputs, one output, a fee of 0.99 BTC and, at 09:50 UTC on 7 November 2026, 917,874 confirmations. No account, no wallet, no permission needed. That page is a block explorer: a website that runs its own nodes, indexes everything the chain has recorded and lets anyone search it by transaction ID, block number or address.
The catch: that page also carries advertising, adds labels that are not on the chain, converts amounts at prices of its own choosing, and has been copied by phishers. Reading an explorer well means knowing which lines come from the chain and which come from the company running the site.
This guided exercise only reads public data. You will open four real transactions on three chains (two on Bitcoin with mempool.space, one on Ethereum with Etherscan, one on Solana with Solscan) and read them field by field, with the values the pages showed on the morning of 7 November 2026. No wallet, no signature, no money. Afterwards you should be able to check your own payment, answer an exchange that says “we sent it”, and keep a usable record for your tax file.
One reminder before starting. Our guide to how a crypto transaction travels from “Send” to final already shows where an explorer fits in that journey, along with fee bumps and replacements. This lesson is the full reading exercise, one screen at a time.
Before you start: three rules for a block explorer exercise
An explorer shows data; it cannot move your coins. The danger comes from pages that only look like explorers, and from buttons on real explorers that ask for a wallet. Three habits remove most of that risk.
- Type the address of the explorer yourself (mempool.space, etherscan.io, solscan.io) or use a bookmark you made. Do not reach it from a search ad, a message or a link someone sent you.
- Do not click advertising or “sponsored” boxes on an explorer page, even a real one. Solscan showed a “Sponsored” slot right next to the fee on the transaction used in this lesson.
- Never connect a wallet to read anything. Every field in this lesson is visible without one. A page that asks you to connect “to view” a transaction is not an explorer.
Exercise 1: the 2010 pizza transaction on mempool.space
The story is told in a Bitcointalk forum thread: on 18 May 2010 a user named laszlo, writing from Jacksonville, Florida, offered 10,000 bitcoins for a couple of pizzas, and on 22 May he posted that the trade had gone through. The transaction he sent is one of the most visited pages on any Bitcoin explorer.
Finding a transaction by its ID
A Bitcoin transaction ID (txid) is 64 hexadecimal characters. For the pizza it starts with a1075db5 and ends with fbf5d48d. On mempool.space, paste the full txid into the search box at the top of the page and press Enter. The same box accepts a block height, a block hash or an address. If you only have part of a txid, do not guess: ask whoever sent the payment for the full one, because two transactions can share their first characters.
Status, confirmations and the time zone trap
The first lines tell you whether the transaction is in a block and how deep. The pizza sits in block 57,043. mempool.space counts the block that contains it as the first confirmation, so with the tip at block 974,916 on the morning of 7 November 2026 the page showed 917,874 (974,916 minus 57,043, plus one). Not every explorer counts the same way, and an exchange that asks for “three confirmations” applies its own rule, not the explorer’s.
The timestamp is where many beginners slip. The block time recorded on chain is 18:16:31 UTC on 22 May 2010, but mempool.space displays times in the time zone of your browser: on a computer set to Paris time the page showed 20:16:31. Etherscan and Solscan, by contrast, print UTC explicitly. When you quote a time to a support desk or put it in a tax record, write it in UTC and say so.
131 inputs and one output: Bitcoin counts coins, not balances
Scroll to the inputs and outputs. On the left, 131 inputs, all from the same old-style address beginning with 1XPTgD. The first few carry 150, 250, 150 and 80 BTC, followed by a long run of 0.01 BTC pieces, adding up to 10,000.99 BTC. On the right, one output: exactly 10,000 BTC to an address beginning with 17SkEw. mempool.space tags the transaction “Consolidation” because so many pieces were merged into one.
This is the UTXO model at work. A Bitcoin wallet does not hold a balance; it holds separate unspent outputs, each spent whole, a bit like notes in a purse. Paying 10,000 BTC took 131 of them. The lesson on the UTXO and account models explains why wallets end up with so many pieces and what that costs.
The fee you will not find written in the transaction
A Bitcoin transaction has no “fee” field. The fee is whatever the inputs hold that the outputs do not pay out: 10,000.99 minus 10,000 leaves 0.99 BTC, or 99,000,000 satoshis, which the miner of block 57,043 collected. The explorer does this subtraction for you, then divides by the size of the transaction to show a fee rate: 23,620 virtual bytes, so 4,191 satoshis per virtual byte (sat/vB). The lesson on the mempool and transaction fees explains why fees are priced per byte and how that rate decides your place in the queue.
There is no change output: the sender combined coins worth exactly the price plus the fee. And the page showed the fee as 0.00 USD, which suggests mempool.space converts at the price of the day: in May 2010 a bitcoin was worth a fraction of a cent. Before you copy a dollar amount from any explorer, check which price it uses.
| Field on mempool.space | Value (read 7 Nov 2026) | What it tells you |
|---|---|---|
| Transaction ID | a1075db5…fbf5d48d (64 hex characters) | The unique reference to give a support desk |
| Block | 57,043 | Where the transaction was recorded |
| Confirmations | 917,874 (09:50 UTC) | Blocks added on top, this one included |
| Timestamp | 22 May 2010, 18:16:31 UTC | Shown in your local time zone by default |
| Inputs / outputs | 131 / 1 | Coins spent and coins created |
| Fee | 0.99 BTC (99,000,000 sats) | Inputs minus outputs |
| Fee rate | 4,191 sat/vB | Fee divided by virtual size (23,620 vB) |
| Miner | Unknown | No pool tag existed in 2010 |
Exercise 2: an everyday payment in the halving block
The pizza is famous but unusual. For an ordinary modern payment, open transaction 8f7f7d66…bddcc4e, included in block 840,000 on 20 April 2024 at 00:09:27 UTC. That block cut the new-coin subsidy to 3.125 BTC, the event known as the Bitcoin halving. On 7 November 2026 the transaction showed 134,917 confirmations.
Payment, change and what address reuse gives away
This one has one input and two outputs, the most common shape you will meet. The input is 0.03278384 BTC from an address starting with bc1q08d9 (a native SegWit address). The outputs are 0.00274228 BTC to an address starting with bc1q0fdd, the actual payment, and 0.02998627 BTC sent back to bc1q08d9, the very address that paid.
That second output is change. The sender had a 0.0328 BTC coin, needed to pay 0.0027 BTC, and got the rest back, minus the fee. You can check the fee yourself in satoshis: 3,278,384 minus 274,228 minus 2,998,627 equals 5,529 sats, exactly what the page shows (it displayed 3.53 USD).
Sending change back to the paying address is called address reuse, and it makes tracing easy: anyone can see that bc1q08d9 kept 0.02998627 BTC and follow it. Most modern wallets send change to a fresh address instead, as our guide to crypto address formats and their privacy costs explains. A small arrow next to each output shows it was spent later; both were, within about two days, in blocks 840,279 and 840,305.
Size, weight, virtual bytes and the RBF badge
Below the amounts, mempool.space lists technical fields. The transaction is 222 bytes but 140.25 virtual bytes, because SegWit counts signature data at a discount; the weight is 561 weight units, and virtual size is weight divided by four. The fee rate is computed on virtual size: 5,529 sats over 140.25 vB gives 39.4 sat/vB, which the page marked “Optimal” for that block.
The feature badges read SegWit, Taproot and RBF. RBF (replace-by-fee) means the wallet left the door open to swap in a higher-fee version while the transaction was unconfirmed; once it is in a block, that is history. The witness holds two items, a signature and a public key: a standard single-key SegWit spend.
Reading the block page: miner, coinbase and the audit
The block number is a link: follow it to block 840,000. The header fields (previous block hash, Merkle root, nonce, bits) are listed at the bottom; our lesson on what a block contains explains them one by one, so we skip them here.
What matters for a reader is above them. The block holds 3,050 transactions, weighs 3,993,281 weight units (just under the 4 million limit) and was mined by the smart contract holding reserves of two or more tokens, supplied by users, that a decentralized exchange uses to execute trades automatically at a price set by a formula.">pool ViaBTC. Fees inside it ranged from 100 to 3,604,819 sat/vB, with a median around 200. Total fees reached 37.626 BTC, more than ten times the subsidy of 3.125 BTC, for a total reward of 40.751 BTC.
The first transaction of every block is the coinbase: it has no real input and creates the reward out of nothing. Here its text decodes to “/ViaBTC/Mined by buzz120/”, and besides the reward it carries two data outputs, one a commitment for Rootstock merge mining (it starts with RSKBLOCK:) and one the SegWit witness commitment. The top fee rate of the block, 3,604,819 sat/vB, belonged to a transaction that paid 6.732 BTC to record a message in the format of Runes, a token protocol for Bitcoin.
mempool.space adds a feature most explorers lack: an audit. It compares each mined block with the block its own nodes expected. For block 840,000 it expected 3,063 transactions and 37.65 BTC of fees, against 3,050 and 37.626 actually mined, and gave a “Health” score of 100%. Our transaction is flagged “Seen in mempool” and “Prioritized”. This is mempool.space’s own model, useful for spotting censored or unexpected transactions, but it is not a rule of Bitcoin.
Exercise 3: a USDC transfer on Etherscan
For Ethereum, open transaction 0x09b57a09…3944502c on Etherscan. It sits in block 15,537,394, produced on 15 September 2022 at 06:42:59 UTC: the first block of Ethereum under proof of stake, the Merge. Inside it is the simplest token payment there is, a transfer of the USDC stablecoin. When the page was read on 7 November 2026, Etherscan showed status “Success” and 10,824,781 block confirmations.
Why “Value: 0 ETH” still moved 20,270.98 USDC
Three lines confuse most beginners. “From” is 0x2FAF487A…776AD2, which Etherscan labels “FTX 1”, a hot wallet of the FTX exchange. “Interacted With (To)” is 0xA0b86991…606eB48, labelled “Circle: USDC Token”. And “Value” reads 0 ETH.
None of them is an error. On Ethereum, a token is a ledger kept inside a smart contract. To send USDC, the sender does not send anything to the recipient; it sends a transaction to the USDC contract asking it to update two balances. No ether moves, hence the zero. The real recipient appears one line lower, under “ERC-20 Tokens Transferred”: 20,270.98 USDC from FTX 1 to an address with an ENS name, 0x7eb241f6…22222222. We do not reproduce that name: it may identify a private person, and an explorer makes it far too easy to attach names to wallets.
Etherscan valued the transfer at $20,265.36. That is today’s USDC price applied to an amount from 2022, not the value on the day. The fee line has the same issue: 0.002635103832064956 ETH, shown as $5.91, at the ether price of about $2,244 that Etherscan displayed around 09:50 UTC on 7 November 2026.
Gas, base fee, tip and the burnt part
Ethereum charges in gas, a unit of computing work, priced in gwei (a billionth of an ether). The explorer splits the bill into fields that only make sense together, as the table shows. Our glossary entry on gas fees covers the vocabulary.
| Field on Etherscan | Value | Meaning |
|---|---|---|
| Gas Limit & Usage by Txn | 76,564 / 48,537 (63.39%) | Maximum allowed versus actually used |
| Gas Price | 54.290620188 Gwei | Effective price paid per unit: base fee plus tip |
| Base fee | 48.811794595 Gwei | Set by the protocol for the block, burnt |
| Max Priority | 5.478825593 Gwei | The tip offered to the block proposer |
| Max fee | 1,000 Gwei | Ceiling the sender accepted, never reached |
| Transaction Fee | 0.002635103832064956 ETH | 48,537 gas x 54.290620188 Gwei |
| Burnt | 0.002369178074257515 ETH | 48,537 gas x base fee |
| Txn Savings | 0.045901896167935044 ETH | (Max fee minus price paid) x gas used |
Of the 0.002635 ETH fee, the base-fee part (0.002369 ETH) was destroyed and the remaining 0.000266 ETH went to the validator as a tip. “Txn Savings” is not money anyone saved: it is the gap between the sender’s very high ceiling and what the block actually charged. There is no fee rate in the Bitcoin sense either, because Ethereum prices computation, not bytes.
The nonce and the position in the block
The nonce is 4,630,922. On Ethereum it counts the sender’s transactions from 0, so this was FTX 1’s 4,630,923rd; your own wallet will show small numbers. Transactions from one address are confirmed in nonce order, which is why one stuck transaction can hold up all the next ones, as the UTXO and account model lesson shows. “Position In Block” is 78: counted from zero, the second-to-last of the block’s 80 transactions.
Input data and logs: decoding the transfer yourself
Open “More details” and the input data. Etherscan decodes it as the function transfer(address to, uint256 value), method ID 0xa9059cbb, with two parameters: the recipient’s address and the number 0x04b83e9ba0. Convert that hexadecimal number and you get 20,270,980,000. USDC uses six decimals, so move the point six places left: 20,270.98 USDC. That is the whole payment, written in 68 bytes.
The “Logs (1)” tab shows the event the USDC contract emitted when it ran: a Transfer event whose first topic (0xddf252ad…) identifies the event type, followed by the sender, the recipient and the same amount. The friendly “ERC-20 Tokens Transferred” line is simply Etherscan reading this log. If a page claims a token transfer happened but there is no matching log, the transfer did not happen.
The Merge block: “Finalized”, slot and epoch
Now follow the block number. Block 15,537,394 carries the label “Network Upgrade Paris” and the note “Ethereum’s Paris Network Upgrade (a.k.a. the Merge!)”. The Merge was a scheduled hard fork, the kind of planned rule change described in the previous lesson, forks explained: soft forks, hard forks and chain splits. Proof of stake itself is the subject of a later lesson on the Merge.
The status reads “Finalized”: on Ethereum, the block sits behind a checkpoint that validators have locked, and the lesson on finality and reorganisations explains what that guarantees. “Proposed On” gives slot 4700013 and epoch 146875, the proof-of-stake clock. The block nonce is 0x0000000000000000 and the difficulty 0, because nobody mines any more. The 80 transactions used 29,983,006 gas out of a 30,000,000 limit, and the block reward of about 45.03 ETH is made of tips only: the execution block issues no new ether.
Address and contract pages on Etherscan
Labels are the explorer’s opinion, not chain data
Back on the transaction, open the “FTX 1” address. On 7 November 2026 the page showed a balance of 0.004677 ETH (about $10.50), more than 5.4 million transactions, a first deposit “Funded By: Binance 4”, and token holdings displayed as more than $477,000 across more than 244 tokens.
Every name there (FTX 1, Binance 4, the “Exchange” type) is a label Etherscan attached, not something written on the chain, and a label can be missing, outdated or wrong; with a login you can add private labels of your own. FTX filed for bankruptcy in November 2022, two months after this transfer, and the labels stayed. The token list mixes real assets with junk, because anyone can send any token to any address: impressive dollar values there prove nothing. Never try to sell or “claim” a token that arrived by itself, a classic bait for scams (see our guide to fake airdrops and giveaways).
The contract tab: verified source, proxy, and why “Write” needs a wallet
Now open the USDC contract page and its “Contract” tab. A green check reads “Source Code Verified” (Exact Match): the code published by the developers compiles to exactly the bytecode on the chain. The contract is named FiatTokenProxy, compiled with Solidity v0.4.24, and the page offers “Read as Proxy” and “Write as Proxy”.
A proxy forwards every call to another contract that holds the logic, here at an address starting with 0x43506849. Whoever controls the proxy can point it to new logic, so the token’s rules can change without a new address: the explorer tells you this for free about any token you hold. Etherscan adds a caution in a tooltip: “Source code verification does not imply the contract is safe to interact with.” Read tabs are harmless. Write tabs send transactions, need a wallet and cost gas; leave them alone in this exercise.
Token approvals: look, but revoke with care
Etherscan’s token approval page presents itself as a place to “Review and revoke your token approvals for any dApp”. An approval is a permission you gave a contract to move your tokens, and forgotten unlimited approvals are a common way wallets get drained. The page lists the approved spender, the asset and the allowance.
On 7 November 2026 its workflow started with a “Connect Wallet” button, and revoking is itself an on-chain transaction you sign and pay for, so in this read-only exercise, do not connect. Approvals you granted also appear as “Approve” calls in your address’s ordinary transaction list, readable without connecting. If you later decide to revoke, type etherscan.io yourself and never follow a revoke link from a message or an ad.
Exercise 4: a Solana payment on Solscan
No famous Solana transaction is simple enough for a first reading, so this one comes from the morning of the lesson: a 50 USDC payment on Solscan, recorded at 09:47:49 UTC on 7 November 2026. The same identifier also opens on the Solana Foundation’s Solana Explorer.
Signature, slot and “Finalized”
Solana has no separate transaction hash: the transaction’s ID is its first signature, a base58 string of about 88 characters (here starting 2Uqkd1bc). Solscan shows it as “Signature”. Two accounts signed this one: the fee payer, starting 9NDLruoc, and a second signer that Solscan labels “Collector Crypt Gacha”, a service label we report as shown without vouching for it.
Solscan’s “Block & Timestamp” line reads 466,467,403. That number is a slot, a short time window in which one designated validator may produce a block. Some slots end up empty, so the block height, 444,486,100 for this block according to a public Solana RPC node, is lower than the slot number.
“Result” reads SUCCESS and “Finalized (MAX Confirmations)”. Solana uses three commitment levels: processed, confirmed and finalized. Finalized means the block has been confirmed by a supermajority of the stake and has reached maximum lockout, so the network treats it as permanent. The finality lesson linked above compares this with Bitcoin and Ethereum.
Fee in lamports, priority fee and compute units
The fee reads 0.0000108 SOL, about $0.001 at the SOL price Solscan showed that morning. Solana counts in lamports: one SOL is one billion lamports, so the fee is 10,800 lamports. Solana’s fee documentation gives the recipe. Each signature costs a base fee of 5,000 lamports, “split 50% burned / 50% to the validator”, and two signatures make 10,000. On top comes an optional priority fee, which goes “100% to the validator”.
The priority fee comes from two instructions inside the transaction: a compute unit limit of 80,000 and a price of 10,000 micro-lamports per unit (a micro-lamport is a millionth of a lamport). 80,000 times 10,000, divided by one million, gives 800 lamports, the “Priority Fee” line, and 10,000 plus 800 is 10,800. The transaction consumed only 31,394 compute units, 39.24% of its limit, yet the priority fee was charged on the full 80,000 requested.
| Field on Solscan | Value (7 Nov 2026) | Meaning |
|---|---|---|
| Signature | 2Uqkd1bc… (88 characters) | The transaction ID |
| Block (slot) | 466,467,403 | Slot number; block height is 444,486,100 |
| Result | SUCCESS, Finalized (MAX Confirmations) | Executed and permanent |
| Fee | 0.0000108 SOL (10,800 lamports) | 2 signatures x 5,000 + 800 priority |
| Priority Fee | 0.0000008 SOL (800 lamports) | 80,000 CU limit x 10,000 micro-lamports |
| Compute Units Consumed | 31,394 of 80,000 (39.24%) | Work actually done |
| Transaction Version | Legacy | Older message format |
| Recent Block Hash | HtzGVEur… | Makes the transaction expire if not included soon |
The version line says “Legacy”. Solana’s fee page, read on 7 November 2026, also describes a newer “v1” transaction format in which the fee is set as an absolute total in lamports, so you may meet “Version 1” on recent transactions and a different fee breakdown.
Instructions, memo and token accounts
A Solana transaction is a list of instructions, each sent to a program. This one has four: set the compute unit limit, write a memo, transfer the tokens, set the compute unit price. The memo instruction wrote a free-text reference on chain, a string ending in “:open” that looks like an order number. Memos are public forever: never put a name, an email or an account number in one, even if a platform asks for a reference.
The transfer itself is a “TransferChecked” of 50,000,000 base units with six decimals, so 50 USDC. Look closely and the source and destination are not the two wallets: they are token accounts (starting 3E8SgJhN and D9CEogjH), small accounts that each hold one kind of token on behalf of an owner wallet. On Solana, your wallet address owns your USDC account rather than holding the USDC directly. The account-model lesson linked earlier shows why Solana stores state this way.
Balance changes: the fastest way to check who paid what
The “Balance Changes” tab shows before and after for every account touched, and is often quicker to read than the instruction list. Read from the chain, the fee payer’s SOL went from 705,338,963 to 705,328,163 lamports, down by exactly the 10,800-lamport fee, and its USDC from 64.026317 to 14.026317. The receiver’s USDC went from 367,176.163055 to 367,226.163055. To prove a Solana payment, these before-and-after lines are the clearest evidence on the page.
What a block explorer gets wrong, and who runs them
The raw data (amounts, addresses, block numbers, signatures) comes from the chain and can be checked against another explorer or your own node. The rest is the operator’s work, and the exercises met each layer: labels, dollar values at today’s price or the day’s, times in UTC or in your browser’s zone, confirmation counts that differ by one. An explorer can also lag, go down, or not yet have seen a transaction your wallet broadcast a minute ago.
When in doubt, check a second explorer run by someone else, and look at who that is. Solscan has belonged to Etherscan since January 2024, The Block reported, so for Solana the independent second opinion is the Solana Explorer.
| Chain | Explorer | Who runs it |
|---|---|---|
| Bitcoin | mempool.space | The Mempool Open Source Project; its software is open source and can be self-hosted next to your own node |
| Bitcoin | blockstream.info | Blockstream; the explorer software is open source |
| Many chains | Blockchair | Blockchair, a private company |
| Ethereum and EVM chains | Etherscan | Etherscan, a private company |
| Ethereum and EVM chains | Blockscout | The Blockscout project; its open-source software runs explorers for hundreds of chains and rollups, Ethereum’s at eth.blockscout.com |
| Solana | Solscan | Etherscan, owner of Solscan since January 2024 |
| Solana | Solana Explorer | The Solana Foundation, which publishes its code |
Explorers also sell data, and that business changed in 2025 and 2026. Etherscan retired version 1 of its API on 15 August 2025, after extending earlier deadlines, according to a notice in its Information Center; version 2 reaches more than 50 chains with one key. On 22 November 2025 the company said it had cut the chains covered by its free API tier by roughly 10%, because free access on every chain “had begun to impact overall service quality”, and added a cheaper Lite plan. CCN reported that Avalanche, Base, BNB Chain and OP Mainnet were among the chains removed, with paid plans from $49 a month. The API changelog shows more of the same in 2026: since 1 July free users get at most 1,000 records per request instead of 10,000, and other chains, Arbitrum from 1 November, moved to a shared free pool or behind paid plans.
Reading the website stays free. The change matters if portfolio or tax software imports your history through an explorer’s API: when such a tool suddenly fails on one chain, a plan change upstream is a likely cause, and the fix is to export the history another way, never to hand your keys to a “sync” service.
Scams that use block explorers
Because people trust explorers, scammers imitate them. On 8 April 2024, Cointelegraph reported that advertisements shown on Etherscan were part of a phishing campaign: they led to fake sites that asked visitors to connect a wallet, then drained it. Scam Sniffer, the anti-scam service cited in the report, found the same ads on Google, Bing, DuckDuckGo and X and blamed weak filtering by ad networks. In September 2024, Protos reported that a lookalike spelt “et-herscan” came second, just below the real Etherscan, in DuckDuckGo and Bing results.
Address poisoning abuses the history you see on an explorer. The attacker creates an address whose first and last characters match one you use, then sends you a tiny or fake transfer from it so it shows up in your list. Later you copy the “familiar” address and pay the attacker. On 3 May 2024, CoinDesk reported that a victim had sent 1,155 wrapped bitcoins, worth about $68 million, to such a lookalike, a loss first flagged by the security firm CertiK. A week later the attacker returned about 22,960 ETH, over 96% of the value, after negotiations, Cointelegraph reported. That ending is rare.
The explorer is also your defence. Before paying, compare the full recipient address character by character, not just the ends, and never copy it from your own transaction list. Zero-value or dust transfers from addresses you do not know, sitting in your history, are a sign you are being targeted. Our guide on how to avoid crypto scams lists the other common tricks.
One last trick needs no technology. A screenshot of a wallet saying “sent” is not proof of payment; a txid that opens on a real explorer, showing the right recipient, amount and confirmations, is. If you sell crypto person to person, insist on the txid and check it yourself.
Using an explorer as proof: tax returns and support tickets
For US taxpayers, the IRS gives explorers a named role. In its virtual currency FAQ, question 27 covers crypto received outside an exchange, for example peer to peer: fair market value is fixed at the date and time the transaction is recorded on the ledger, and the IRS says it will “accept as evidence of fair market value the value as determined by a cryptocurrency or blockchain explorer”. The same answer specifies an explorer that works from worldwide price indices and computes the value at the exact date and time; if you use another value, you must show that it is accurate. A token priced at today’s rate, as Etherscan did in Exercise 3, does not meet that test. Question 46 asks taxpayers to keep records “sufficient to establish the positions taken on tax returns”. Our guide to crypto taxes in the United States covers the rest.
In practice, for each move between your own wallets or any payment outside an exchange, save the explorer URL, the txid, the UTC timestamp, the amounts and the fee, and note which price any dollar figure uses. Exchanges do not see what you do in self-custody; the chain records it, and the explorer is how you show it. The same habit helps in the UK, France or Italy, where tax returns also rest on records you keep yourself.
Support tickets work the same way. When a deposit does not arrive, an exchange will ask for the txid. Check first that the transaction is confirmed, that the recipient is exactly the deposit address the exchange gave you, and that the network is the right one. On chains where platforms require a memo or tag next to the address, a missing memo is the classic “lost” deposit; only the platform’s own support can sort it out, never a “recovery service” that contacts you.
A checklist for reading your own transaction
Once you have done the four exercises, reading your own transaction takes a minute. Open the explorer by typing its address, paste the full ID, and go down this list.
- Check the status. Pending means not yet in a block; a failed Ethereum transaction still cost gas.
- Compare the confirmations, or the finality status, with what the receiving platform requires.
- Read the full recipient address, character by character, and for tokens the line that names the real receiver rather than the contract.
- Check the amount, the token, its decimals and the network it is on.
- Work out the fee: inputs minus outputs on Bitcoin, gas used times price on Ethereum, lamports on Solana.
- Note the time in UTC and whether any dollar figure is today’s price or the day’s.
- Save the URL with your records.
If one line does not match what you expected, open the same ID on a second explorer from a different operator before you contact anyone. Two explorers will often disagree on labels and prices; on amounts, addresses and block numbers they should not.
