Banking API: how to automate cash flow reporting

A banking API lets a company download account activity automatically, several times a day, without manually exporting statements. Instead of someone retyping figures from internet banking into a spreadsheet on Friday morning, the bank sends transactions straight into the reporting system. The system sorts them into categories on its own, calculates the current balance across all accounts and currencies, and updates the cash forecast. The legal basis is the European PSD2 directive, which obliged banks to open access to account data for licensed providers.¹ The result is a live cash flow position, not a week-old spreadsheet.

Most companies with turnover of CZK 50 to 500 million manage cash on the basis of data that is already out of date by the time a decision is made. Someone downloads a statement, retypes it into Excel, calculates the balances and sends the report to the owner. This cycle takes hours and repeats every week. A banking API removes this manual work: the data flows from the bank into the reporting on its own. In this article we explain what open banking technically enables, what regulatory basis it stands on, and how we use it to feed a thirteen-week cash forecast every day.

What a banking API and open banking are

An API (application programming interface) is a standardised interface through which two systems communicate without a person in the middle. A banking API therefore lets your reporting tool ask the bank for a list of transactions and balances and receive them back in machine-readable form. Open banking is a broader concept: it refers to the arrangement under which a bank, on the client's instruction, makes data about the client's account available to a third party that the client has chosen.

The key phrase is "on the client's instruction". The bank does not hand data to just anyone. Access is granted explicitly by the account holder, is time-limited and can be revoked at any time. In practice this means that you, as a company, tell the bank "this provider may read the activity on my current account", and from that moment the system downloads the data automatically until you withdraw the consent.

PSD2: the regulatory basis it stands on

Open banking in Europe is not a matter of banks' goodwill but a legal obligation. It stems from Directive (EU) 2015/2366 of the European Parliament and of the Council on payment services in the internal market, known as PSD2, adopted on 25 November 2015.¹ The directive introduced two new regulated services based on access to account data: the account information service (AIS) and the payment initiation service (PIS).²

For cash flow reporting, AIS is the most relevant. On its basis a licensed provider may, with your consent, read transactions and balances. Banks had to open up this option technically: the main PSD2 rules have applied since 13 January 2018, and the related regulatory technical standards, including strong customer authentication, applied no later than from 14 September 2019.¹ The central register of licensed providers is maintained by the European Banking Authority (EBA); licensing itself and supervision are handled by national supervisory authorities, in the Czech Republic the Czech National Bank.²

In practice this means two things. First, access to data via the API is standardised and regulated, not an improvised export. Second, the provider you allow to reach your account must hold a licence and is subject to supervision. From the standpoint of corporate data security, this is a fundamental difference compared with sharing your internet banking login credentials, which you should never do.

What the API actually automates

Three things you do manually today are taken over by a system connected through a banking API.

Daily transaction downloads. Every day, and where needed several times a day, the system connects to the bank and downloads new activity. No export, no copying, no human error in retyping.

Automatic categorisation. Each transaction is sorted into a cost or revenue category based on the counterparty, the variable symbol or the payment description. For recurring payments, which make up the majority in a typical company, the sorting works reliably once the rules are set.

Live cash position. If you have three current accounts plus a euro and a koruna account, the API merges them into a single consolidated balance. The owner sees one number that is valid now, not a number from last Friday.

Why it matters: speed of decision-making

Cash management is a game against time. A company can be profitable and still run into a liquidity problem because the money comes in later than it goes out. Pressure on cash flow is meanwhile rising in Europe: according to the European EU Payment Observatory's Annual Report 2024, the average payment time for B2B transactions reached 61.8 days, and for payments from the public sector (G2B) around 69 days.³ Almost half of companies (47%) reported in the survey that they had run into difficulties because of late payments, and in twelve member states this affected more than half of companies.³

When invoices arrive with almost a two-month delay, the difference between a week-old and a current cash forecast is the difference between a timely intervention and a crisis. Automated reporting gives you time to react: to postpone a non-essential expense, chase a specific receivable, or negotiate drawing on an overdraft a week earlier. Manual reporting spends that time on simply assembling the figures.

How we do it at numericky.cz

For clients we connect bank accounts through a licensed open banking connection and download transactions daily. The data is categorised automatically and flows straight into the thirteen-week cash forecast, so the forecast is not a monthly ritual but a live tool that updates itself every day with new activity. The owner then sees the consolidated cash position and the short-term forecast in a dashboard, without anyone touching a spreadsheet.

This does not replace your accountant or your accounting software. The API serves to manage cash and liquidity, not to keep the books. Accounting continues at its own pace and on its own closing cycle; cash flow reporting runs in real time alongside it. The two layers complement each other: accounting gives an accurate picture of the past, the API-connected forecast gives a usable picture of the coming weeks.

From our experience, the biggest benefit is paradoxically in what disappears. The Friday morning spent assembling a report disappears, retyping errors disappear, and the situation disappears where the owner asks "how much do we actually have in the accounts" and the answer takes an hour. That is the point of automation: not flashier spreadsheets, but faster and calmer decisions about money.