diff --git a/backend/src/utils/liquidityForecast.ts b/backend/src/utils/liquidityForecast.ts
index 05bc464..986d40f 100644
--- a/backend/src/utils/liquidityForecast.ts
+++ b/backend/src/utils/liquidityForecast.ts
@@ -119,6 +119,12 @@ const getIncomingInvoiceSignedAmount = (invoice: any) => {
     return roundMoney(invoice.expense === false ? amount : amount * -1);
 };
 
+const getRemainingSignedAmount = (signedAmount: number, allocatedAmount: number) => {
+    const remainingAbsolute = Math.max(0, Math.abs(Number(signedAmount || 0)) - Math.abs(Number(allocatedAmount || 0)));
+    if (remainingAbsolute <= 0.01) return 0;
+    return roundMoney(Math.sign(Number(signedAmount || 0)) * remainingAbsolute);
+};
+
 const findCancellationDocumentIds = (documents: any[]) => {
     return new Set(
         documents
@@ -392,7 +398,7 @@ export const generateLiquidityForecast = async (
         .filter((invoice) => !invoice.paid)
         .forEach((invoice) => {
             const signedAmount = getIncomingInvoiceSignedAmount(invoice);
-            const openAmount = roundMoney(signedAmount - (allocationByIncomingInvoice.get(invoice.id) || 0));
+            const openAmount = getRemainingSignedAmount(signedAmount, allocationByIncomingInvoice.get(invoice.id) || 0);
             if (Math.abs(openAmount) <= 0.01) return;
 
             const dueDate = dayjs(invoice.dueDate || invoice.date).isValid()