Phoenix Wallet Tax Guide: Lightning & On-Chain Cost Basis

Looking to track your Phoenix Wallet transactions with Bitcoin-only accounting software for accurate tax reporting? This guide walks you through importing Phoenix Wallet's CSV export into Clams using the native Phoenix connection. Clams understands Phoenix's export format directly, so there is no spreadsheet work or manual conversion. Export once from Phoenix, import, and track both Lightning and on-chain transactions with accurate cost basis calculations.

Why Import Phoenix Wallet Data to Clams?

Phoenix is a popular non-custodial mobile Bitcoin wallet that combines Lightning Network payments with on-chain support. When paired with Clams' Bitcoin-only accounting software, you get:

Accurate cost basis - Calculate gains/losses for every transaction
Tax-ready reports - Export formatted data for tax filing
Lightning precision - Track down to the millisatoshi level
Privacy-first - Your data stays on your device

Before You Start

What You'll Need:

Your Phoenix CSV export file
Clams installed

If you have not set Clams up yet, install it and initialize your books:

curl -sSL https://clams.tech/install.sh | sh
clams init

Time Required: A few minutes. Clams parses Phoenix's CSV natively, so there is nothing to convert by hand.

A Note About On-Chain Deposit Addresses

Phoenix's CSV export does not include the on-chain addresses where you deposited funds. Without those addresses, Clams cannot match a deposit to one of your other wallets, so it treats the deposit as income.

Why this matters: If you funded your Phoenix wallet from another wallet (like an exchange or hardware wallet), Clams can only recognize it as a transfer if it can see both sides. The most reliable way to get accurate transfer detection is to connect your other wallets to Clams (via Xpub or Descriptor) so Clams sees the matching outgoing transaction. Your balance is correct either way; this only affects whether a deposit is labeled as a transfer or as income.

Export Your Phoenix CSV

First, export your transaction history from Phoenix Wallet. Follow these steps:

Click full payment history at the bottom of home screen:

Click export icon at top right of the next screen:

Click export button at bottom of the next screen:

Save the exported file somewhere you can find it from the terminal (the examples below assume phoenix.csv in your current directory).

Import to Clams

Create a Phoenix connection, then import the CSV you exported. Clams handles the Phoenix format natively, so you point it straight at the raw export:

clams connections create --label my-phoenix --kind Phoenix

clams connections import \
  --label my-phoenix \
  --input-format csv \
  --file phoenix.csv

clams journals process

Clams parses each row, normalizes amounts and fees, and calculates cost basis using your selected accounting method (FIFO, LIFO, etc.). Re-imports are safe: rows are deduplicated by their canonical ID, so you can export again later and import the new file without creating duplicates.

Understanding Your Balance

Phoenix tracks balance in millisatoshis internally but only displays whole satoshis. Your Clams balance may be 1 satoshi higher or lower than Phoenix shows.

While Phoenix is a non-custodial wallet (you control your keys), Clams will technically label it as a custodial wallet when you import it. This is intentional and perfectly fine.

Phoenix uses a technique called splicing where:

On-chain receives are automatically converted into Lightning channel capacity
On-chain sends reduce Lightning channel capacity (via splicing)

This creates a unique accounting challenge. Until we develop better splicing support in Clams, treating Phoenix as a custodial wallet is the most accurate way to handle these transactions.

Pro Tips for Phoenix + Clams

Regular Imports

Phoenix doesn't support continuous syncing like Xpub-based wallets. Plan to:

Export and import monthly, quarterly, or before tax season
Keep your CSV exports organized by date
Re-run the import whenever you have a fresh export; duplicates are handled for you

Improve Transfer Detection

To maximize transfer detection between Phoenix and your other wallets:

Connect your other wallets to Clams using Xpubs or Descriptors
Clams will automatically detect when Phoenix deposits came from those wallets and label them as transfers instead of income

Multiple Phoenix Wallets

If you have multiple Phoenix wallets:

Import each wallet's CSV under its own connection
Use descriptive labels (e.g. phoenix-old-phone, phoenix-current)

Next Steps

Review imported transactions for accuracy
Set up additional wallet connections to capture all your Bitcoin activity
Configure your accounting method (FIFO, LIFO) if you haven't already
Generate tax reports when needed:

clams reports capital-gains --format csv

Keep your Phoenix taxes sorted

With your Phoenix history in Clams, a capital-gains report is one command. Clams calculates cost basis across your Lightning and on-chain transactions and exports audit-ready reports for tax season. New to Clams? See how it works for individuals.

Need Help?

Having trouble with your Phoenix import? We're here to help:

Join our Matrix community for quick assistance
Email us directly: hello@clams.tech

Common issues:

Import fails: Make sure you exported the complete history from Phoenix and pointed --file at the raw export
Missing transactions: Ensure you exported the complete history from Phoenix
Deposits show as income: Connect the wallet you funded Phoenix from so Clams can match the transfer

About Phoenix Wallet: Phoenix is a non-custodial, self-custodial Lightning wallet developed by ACINQ. It provides automated channel management, making Lightning Network payments accessible to mobile users without technical complexity.

About Clams: Clams is purpose-built Bitcoin accounting software that provides accurate cost basis tracking and exports reports like capital gains for individuals, businesses and enterprises.