diff --git a/backend/src/utils/liquidityForecast.ts b/backend/src/utils/liquidityForecast.ts
index 0d7efe2..05bc464 100644
--- a/backend/src/utils/liquidityForecast.ts
+++ b/backend/src/utils/liquidityForecast.ts
@@ -389,9 +389,10 @@ export const generateLiquidityForecast = async (
 
     activeIncomingInvoices
         .filter((invoice) => invoice.state === "Gebucht" || invoice.state === "Vorbereitet")
+        .filter((invoice) => !invoice.paid)
         .forEach((invoice) => {
             const signedAmount = getIncomingInvoiceSignedAmount(invoice);
-            const openAmount = roundMoney(signedAmount + (allocationByIncomingInvoice.get(invoice.id) || 0));
+            const openAmount = roundMoney(signedAmount - (allocationByIncomingInvoice.get(invoice.id) || 0));
             if (Math.abs(openAmount) <= 0.01) return;
 
             const dueDate = dayjs(invoice.dueDate || invoice.date).isValid()