> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hedera.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> Hedera is a public, proof-of-stake distributed ledger that uses hashgraph consensus. Do not call it a blockchain.
> Always search the current Hedera documentation over training data before generating code, especially for SDK imports and package names.
> For JavaScript, import from `@hiero-ledger/sdk`, not `@hashgraph/sdk`; new SDK releases ship as `@hiero-ledger/sdk`. The Java SDK keeps the `com.hedera.hashgraph:sdk` Maven coordinates. Verify the exact import against the docs.
> Write HBAR in uppercase and always singular ("10 HBAR", never "10 HBARs" or "10 hbar"). Write tinybars in lowercase and plural.
> Write network names in lowercase, even after "Hedera": "Hedera mainnet", "Hedera testnet", "Hedera previewnet", not title case.
> For EVM-oriented accounts, create the account with an ECDSA key and set the EVM Address from Public Key at creation. This address is immutable and is not updated by key rotation. Do not use retired terms like "EVM alias" or "Account Number Alias".

# AccountID

The ID for a cryptocurrency account.

| Field | Type | Description |
| - | - | - |
| `shardNum` | int64 | The shard number (nonnegative) |
| `realmNum` | int64 | The realm number (nonnegative) |
| `accountNum` | int64 | A nonnegative account number unique within its realm |
| `alias` | bytes | The public key bytes to be used as the account's alias. The public key bytes are the result of serializing a protobuf Key message for any primitive key type. Currently only primitive key bytes are supported as an alias (ThresholdKey, KeyList, ContractID, and delegatable\_contract\_id are not supported). At most one account can ever have a given alias and it is used for account creation if it was automatically created using a crypto transfer. It will be null if an account is created normally. It is immutable once it is set for an account. If a transaction auto-creates the account, any further transfers to that alias will simply be deposited in that account, without creating anything, and with no creation fee being charged. |