Handle transfers

A transfer moves an asset into or out of an account without a sale. When an asset arrives from outside your platform, Taxbit has no record of what it cost, so the lot it creates is missing cost basis, and a later sale from it cannot produce an accurate gain. This walkthrough sends a transfer, shows the gap, and points to the four ways to fill it.

By the end of this page you have sent a deposit, seen its lot marked as missing cost basis, and know which of the four child pages applies to your case.

Before you begin

A bearer token. See Authenticate your tenant.
An account with transactions. See Set up inventory and gains.

Send the transfer

A transfer in is a deposit, and a transfer out is a withdraw, both sent to POST /v1/transactions/external-id. The subtype says what kind of transfer it is:

Type	Subtypes
`deposit`	`ach`, `blockchain`, `card-reward`, `gift`, `cost-basis-fmv`, `inheritance`, `internal-personal`
`withdraw`	`ach`, `blockchain`, `gift`, `internal-personal`

This account receives 0.75 ETH from an outside wallet:

curl -X POST $BASE_URL/v1/transactions/external-id \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "id": "dep_40731",
    "account_id": "acct_5f2e7d10",
    "type": "deposit",
    "subtype": "blockchain",
    "datetime": "2026-09-02T09:15:00Z",
    "received": [{
      "asset_amount": { "amount": "0.75", "asset": { "code": "ETH", "type": "Crypto" } },
      "rates": [{ "amount": "3100.00", "asset": { "code": "USD", "type": "Fiat" } }]
    }]
  }'

You should see 201 with "status": "success".

See the missing cost basis

Read the account's ETH inventory, as in Retrieve inventory. The lot the deposit created carries missing_cost_basis: true and no cost, and the summary counts it in total_quantity_missing_cost_basis. By default, every lot created from a transfer starts this way.

Give the deposit a basis

Pick the page for how the asset reached the account:

The asset came from	Do this	Page
Outside your platform, and the user can tell you what they paid	Attach user-entered lots to the deposit	User-provided cost basis
Another account of the same user on your platform	Link the withdrawal and the deposit	Internal personal transfers
Another person, as a gift	Link to the gifter's withdrawal, or attach lots	Gifts
An estate	Send the deposit with subtype `inheritance` and the value at the date of death	Inheritance

Two more cases are not transfers between accounts. A deposit with subtype cost-basis-fmv records an asset acquired at its fair market value: the lot's cost is its value from rates, plus any fee, so it never starts as missing cost basis. A cost-basis-transfer with subtype wrapping or asset-name-change moves basis from one asset to another. It takes exactly one sent and one received entry, with different assets; the sent lots' total cost and acquisition dates carry to the received asset, with quantity and unit cost rescaled to the received amount; any received quantity the sent lots don't cover is missing cost basis; and a fee on it is a taxable disposition. Its fields are in the Transactions reference.

Where to go next

User-provided cost basis, for a deposit from outside your platform.
API reference: Create transfer lots, Create transaction.