how do I provide an expected cashflow when opening an account

Expected cash flow is an estimate, not annual figures

Enter here a reasonable estimate of the incoming and outgoing cash flows for the coming period, usually the first year. The bank is not asking for this to check whether you are right, but to determine what a normal transaction pattern is for your company. A wholesaler with expected turnover of three million and monthly incoming and outgoing payments of hundreds of thousands of euros has a different profile than a sole proprietorship with turnover of fifty thousand. The bank will use this estimate later to flag deviations: a sudden stream of transactions that does not match what you specified at onboarding will be noticed more quickly.

If you do not yet have annual figures, for example as a starting company, usually a reasoned estimate based on order portfolio, contracts or a business plan will suffice. If the company has been in existence for longer, the information usually aligns with the turnover and costs from the latest annual accounts or management reporting. Note that this is different from the question about the average payment term to suppliers: that concerns payment behaviour, this concerns the volume and direction of cash flows. Also different from the question about the source of the company's assets, which looks at origin, not future flows.

Customer due diligence when opening an account

This question stems from the customer due diligence that banks must perform under the Anti-Money Laundering and Countering the Financing of Terrorism Act. A bank must have insight into the expected use of the account in order to identify unusual transactions later; the expected cash flow is one of the standard information items requested at onboarding, alongside for example the ultimate beneficial owners of the company.