> 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/trader-documentation/building-a-trading-bot-legacy-guide/part-1-one-time-on-chain-setup/fund-the-sub-account.md).

# Fund the sub-account

Trades reference the sub-account's collateral balance on the Symmio core. You need balance there before you can open anything.

**Signed by:** Owner EOA, two transactions.

**Function:** First, `approve(spender = AccountLayer, amount = max)` on the collateral token, then [`depositForAccount(subAccount, amountWei)`](https://intent.symmscan.com/inspector/hyperevm/account-layer?method=0x342fcda9) on the AccountLayer.

`depositForAccount` (note: not `depositAndAllocateForAccount`) pulls the collateral from your EOA and credits it to the sub-account's balance on the Symmio core. The AccountLayer signs the inner `deposit` call to the core on your behalf via its `globalSigner` mechanism, so from the core's perspective the sub-account is the depositor.

You can re-run this any time you want to top up. You can also withdraw and re-deposit: the sub-account is sticky, the balance isn't.


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