Yes, it does.
You will need to have available funds in your London House Exchange account to be able to make a bid on the Exchange.
Your maximum exposure from bids is limited to the available funds in your account. If you don't have available funds, then you can't bid at any price. However, if you increase your available balance (such as through receipt of dividends, making a deposit, selling shares or receiving a promotional benefit), then those available funds can be matched against your resting bids. For this reason if you do not want increases in available funds to match against your bids then you should cancel those bids.