If your books run on DATEV — the accounting and payroll platform used by most German small and mid-sized companies and the external tax advisors (Steuerberater) who often run their bookkeeping — you already have the key inputs for a cash flow forecast in-house. They just don’t arrive as a ready-made, week-by-week view. In practice, forecasting with DATEV means pulling the right reports and open items out of it and building a rolling 13-week view from them.
This guide walks through what DATEV delivers, how to export open items, and how that export becomes a forecast you can rely on.
What DATEV gives you toward a forecast — and what it doesn’t
DATEV is strong at what it’s built for: ongoing financial bookkeeping and the reports that come out of it. Three parts of it matter for cash flow:
- Open items lists: every receivable and payable invoice not yet settled — the incoming and outgoing side of the coming weeks.
- The BWA and trial balance reports. The BWA (Betriebswirtschaftliche Auswertung — DATEV’s standard monthly management P&L) shows profitability and account movements — useful, but a profit view, not a cash-timing one.
- DATEV Unternehmen online: a shared portal giving both the company and its tax advisor access to documents, bank transactions and reports.
What DATEV doesn’t replace out of the box is a rolling, week-by-week view: expected receipts set against expected payments per week, against the running balance, over a quarter. That’s the view that turns “the numbers are correct” into “I can see the shortfall before it arrives” — the 13-week cash flow forecast guide explains how that view is built.
Exporting open items from DATEV
Every forecast rests on the open items. DATEV’s accounting programs can output the open items lists for receivables and payables as a report or a file. A few things matter when you do:
- Due dates. They determine which week a payment is expected in. Without a due date, there’s no week-by-week planning.
- Receivables and payables kept separate. Receivables are the incoming side, payables the outgoing one.
- A consistent, repeating format. If the export looks the same every week, it can be processed without manual rework each time.
For more on the open items list itself — its structure, receivables versus payables, how it’s used — see the open items list guide. If your books run on SAP Business One rather than DATEV, the equivalent DACH mid-market ERP, the underlying logic is the same, only the export screen differs.
Four things that trip people up
Four spots regularly go wrong when DATEV data is turned into a cash flow forecast:
- A due date is not a payment date. The open items list says when an invoice falls due — not when the customer actually pays. Planning strictly by due date systematically overstates the early weeks. It’s more realistic to factor in each customer’s actual payment behaviour; the gap between the two can be sized with a DSO calculation.
- Early-payment discounts and partial payments distort amounts. An open item sitting at the gross amount may get settled for less once a discount is taken; partial and advance payments show up differently depending on how they’re posted. Both need clarifying once, or every week will look slightly “off” for no obvious reason.
- Recurring payments often aren’t in the open items list. Payroll, tax and loan repayments typically run without an open invoice behind them — they need their own schedule alongside the export. Watch rent and leasing in particular: if they’re posted as a payable invoice, they’re already in the open items list. Only add to the schedule what doesn’t already appear there — otherwise the forecast counts the same payment twice and looks gloomier than it is.
- A one-off export goes stale fast. A forecast built on an open items list from three weeks ago isn’t a forecast anymore. The export needs a fixed weekly rhythm — or a connection that makes the manual pull unnecessary.
From the DATEV export to a 13-week view
The weekly plan comes together from the exported open items, the recurring and scheduled payments (payroll, rent, tax, loan repayments) and the current bank balance — which comes from your bank statement in MT940 or CAMT.053 format: each week’s receipts minus payments roll forward against the opening balance, carried across 13 weeks. The lowest point on that curve is the number that matters.
The hard part isn’t building the plan once — it’s the weekly update: pulling a fresh open items list, matching incoming payments, rolling the numbers forward. This is where LiquidityLens comes in: it reads your DATEV exports (open items) directly, forecasts expected receipts from actual payment patterns, and rolls the 13-week view forward with AI — no IT project, built from data your bookkeeping already produces.
LiquidityLens turns your DATEV exports and bank transactions into a rolling 13-week forecast — with automatic categorisation and low-point warnings.
See the Liquidity Control SprintA starting point built around your open items lists — weekly grid, receipts and payments, low-point warning. Ready to use.
Frequently asked questions
The most common questions on cash flow forecasting with DATEV are gathered at the end of this page.