> For the complete documentation index, see [llms.txt](https://docs.symm.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.symm.io/exchange-builder-documentation/frontend-builder-technical-guidance/creating-an-account-and-depositing-funds.md).

# Creating an Account and Depositing Funds

In Symmio v0.8.5 a user's trading capital lives in a **SubAccount** created on the **AccountLayer**, a single shared diamond that manages every frontend's accounts. You no longer deploy your own account contract: you register as an affiliate, and users create SubAccounts under your affiliate on the shared AccountLayer.

SubAccounts and the VirtualAccounts beneath them are virtual (CREATE2-style) addresses with no deployed bytecode; the AccountLayer holds their state. For the full account model and the isolation types, see Building a New Frontend.

#### Step 1: Create a SubAccount

`createSubAccounts(affiliate, accountsData[])` creates one or more SubAccounts under your affiliate. The Symmio core, isolation type, name, metadata, and single-VA flag are *fields of the `SubAccountCreationData` struct*, not positional arguments:

```python
# SubAccountCreationData = (name, metadata, symmioCore, isolationType, singleVAMode)
# isolationType uses SubAccountIsolationType: 0=POSITION, 1=MARKET, 2=MARKET_DIRECTION, 3=CUSTOM
sub_account_data = [(
    "TradingAccount",      # name
    b"",                   # metadata
    symmio_core_address,   # symmioCore
    0,                     # isolationType (POSITION)
    False,                 # singleVAMode
)]

account_layer.functions.createSubAccounts(
    affiliate_address,
    sub_account_data,      # array, create several at once if you like
).transact({"from": user})
```

`createSubAccounts` returns the deterministic addresses of the created SubAccounts and emits `SubAccountCreated` for each. To list a user's SubAccounts later, call `getUserSubAccountsAddresses(user, start, size)` on the AccountLayer.

{% hint style="info" %}
Migrating an existing MultiAccount frontend? The **AccountManager** wrapper exposes the old API (`addAccount`, `getAccounts`, `_call`) and creates CUSTOM-isolation SubAccounts that behave like the old model, so you can swap a contract address and migrate fully later. See Upgrading from MultiAccount (0.8.4).
{% endhint %}

#### Step 2: Deposit collateral

Collateral goes into the SubAccount on the AccountLayer. You can deposit alone, or deposit and allocate in a single call:

```python
# Deposit into the SubAccount balance
account_layer.functions.depositForAccount(sub_account, amount).transact({"from": user})

# Or deposit and allocate in one call
account_layer.functions.depositAndAllocateForAccount(sub_account, amount).transact({"from": user})
```

The actual ERC20 `transferFrom` happens inside the Symmio Core diamond, so **Symmio Core** is the address that needs the collateral allowance, not the AccountLayer. Approve it once before the first deposit:

```python
collateral.functions.approve(symmio_core_address, 2**256 - 1).transact({"from": user})
```

`amount` is in the token's native decimals; Symmio converts to 18-decimal fixed-point internally, so the same code works for 6-decimal USDC and 18-decimal stablecoins. Read the collateral token address from `getCollateral()` on the Symmio Core view facet and its decimals from the token's `decimals()`. On success you'll see `DepositForAccount`, plus `AllocateForAccount` if you allocated.

#### Step 3: Fund the VirtualAccount before trading

On a non-CUSTOM SubAccount the margin for a trade lives in a **VirtualAccount (VA)** beneath the SubAccount, not in the SubAccount itself. Before the first trade you fund the *next* VA; the AccountLayer derives which VA that is from the isolation type and symbol, so you don't pass a VA address. The VA isolation type uses `VirtualAccountIsolationType` (`POSITION`, `MARKET`, `MARKET_LONG`, `MARKET_SHORT`):

```python
va_isolation_type = 0  # VirtualAccountIsolationType.POSITION
symbol_id = 1

margin_facet.functions.addMarginToNextVA(
    sub_account, va_isolation_type, symbol_id, amount
).transact({"from": user})
```

To top up a VA that already exists, use `addMargin(virtual_account, amount)`. On a CUSTOM SubAccount there's no automatic VA: trades run directly through the SubAccount, like the old MultiAccount model.

Once the SubAccount is funded and the VA has margin, you're ready to send a quote.


---

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