Transfer ARC-20

Before you start

• Supported networks: mainnet.
• Status: protocol behavior.
• You need a wallet or builder that works in outpoints and satoshi values, not in an amount field.

The whole risk is in the output sizes

Sizes are in satoshis, not in a token amount box. Get one wrong and the remainder burns.

The shape that works

Position	Contents
Input 0	The coloured lot
Input 1 and later	Cardinal inputs for the fee
Output 0	The recipient, sized to exactly the units you are sending
Output 1	Coloured change, sized to exactly the remainder
Output 2	Cardinal change, if any

The procedure

1. List your coloured outpoints and pick the lot to spend.
2. Decide the amount to send. That number is also the satoshi value of output 0.
3. Compute the remainder: lot value minus amount sent. That is the satoshi value of output 1.
4. Model the exact input and output set in the allocation visualizer.
5. Confirm the burn figure is zero.
6. Add cardinal inputs for the fee and a cardinal change output last.
7. Re-model with the fee inputs and outputs included. The burn figure must still be zero.
8. Build the transaction, preserving your input and output order.
9. Compare the wallet prompt to your model, line by line.
10. Sign and broadcast.

Why step seven exists

Adding a fee input or a change output changes the output set, and the allocation walks outputs in order. A transfer that was clean before the wallet added change can burn after it.

The two vectors that show the risk

Executed ARC-20 allocation vectors from conformance/vectors/arc20-allocation.json

Case	Coloured inputs	Result per output	Burned	Clean
A remainder smaller than the change output burns dust-remainder-burns	1200 units at input 0	out 0: 1000 sats to 1000 units; out 1: 200 sats to 200 units	none	yes
A change output larger than the remainder burns it change-output-too-large	1200 units at input 0	out 0: 1000 sats to 1000 units; out 1: 546 sats to 0 units	200 units of TOKENA	no

Same intent, same lot, same amount sent. The only difference is the change output size, and one of them destroys 200 units.

Cost

One Bitcoin fee, paid from a cardinal input. No commit and reveal pair, and no grinding, for an ordinary transfer.

If it fails

• The wallet will not let you set output values in satoshis: use a different builder.
• The wallet reorders outputs: use a different builder. Order is meaning.
• The burn figure is not zero: change the output sizes, do not proceed.

After broadcast

Confirm, wait for indexing, read the asset location, and check the recorded burn figure. See verify a transaction.

Source

Allocation and burns.