How will I know when an IPO is available to accept Conditional Offers to Buy?

No.  There are no fees or commissions associated with entering a Conditional Offer to Buy (COB) or receiving an US IPO allocation.  However, there will be a commission charge on the sale of any securities received according to the account’s commission schedule…

Yes. Conditional Offers to Buy (COB) can be modified or canceled until the Notice of Acceptance is sent.  To cancel a COB while the US IPO is open for COB submission can be done through Client Portal.

To canceled or modified a COB follow these steps:…

In the event of material changes to the prospectus, Interactive Brokers (IBKR) may need to reconfirm your Conditional Offer to Buy (COB). If a reconfirmation is needed, a message will be sent to impacted accounts. Failure to reconfirm your COB will result in the COB being canceled…

Placing a Conditional Offer to Buy (COB) an US IPO will not impact your trading.

The account must have enough Excess Liquidity to cover the COB amount when the COB is submitted. However, this Excess Liquidity requirement will not restrict your ability to trade other securities or withdraw funds from your account. …