Inventory Management with Magic Heidi: Simple Stock Tracking for Swiss Freelancers

The simplest way to manage inventory with Magic Heidi is through a credit system built from a paid invoice and multiple delivery notes. You create one invoice for the full order quantity, the customer pays upfront, and then you document each partial delivery with a separate delivery note until the order is completely fulfilled.

What if you could ditch the complicated Excel juggling you do every month just to keep track of your stock? That's exactly what this is about. Magic Heidi is lean accounting software for Swiss freelancers — not an ERP platform with a sophisticated inventory management system. But for many typical freelancer scenarios where you deliver products to a customer across multiple shipments, it's more than enough.

In this article, I'll show you how to use a single invoice and a series of delivery notes to keep track of what you've already delivered and what's still outstanding. You'll get a concrete step-by-step guide, three real-world examples from Swiss self-employed professionals, and a simple logic that always tells you how much stock a customer still has coming to them.

You'll find the key takeaways as a compact summary further down.

Why Traditional Inventory Software Is Overkill for Most Freelancers

If you're a freelancer in Switzerland selling wine, cheese, coffee, handmade soaps, or other physical products, you probably don't have 10,000 items in stock. You might have a handful of regular customers who order larger quantities, and you just want to know what's still outstanding.

Full-blown inventory software like SAP or Odoo is completely overkill here. You're paying monthly licensing fees, spending hours setting up product master data, and still needing an accountant to help you navigate it. None of that makes sense for a freelancer with five to ten active customers.

That's exactly where the Magic Heidi trick comes in: you use tools you already have — invoices and delivery notes — and combine them into a lean inventory system. Looking for a streamlined solution for your accounting? See how Magic Heidi works for freelancers.

The Core Principle: Paid Invoice Plus Running Credit

Before we get into the step-by-step guide, here's the core idea in two sentences. You always have two documents per order: a paid main invoice that keeps your accounting clean, and a second invoice you use as a running "IOU" toward the customer. The second invoice is never paid — it only serves as an internal overview.

Why Two Invoices Instead of One?

The separation matters because your accounting needs to be clean for tax purposes. The paid main invoice documents the actual flow of money from the customer to you. The second invoice is just a tool — it's never posted as a transaction and simply gets archived at the end.

This keeps your official accounting lean and correct while you still maintain operational oversight. If you're generally interested in the basics of Swiss freelancer accounting, check out our tutorials for more.

Step-by-Step Guide: How to Set Up Your Inventory Management

Let's take the example of Lina, a fictional cheese producer from the Emmental. She has a regular customer — a small organic café in Bern — that wants to order a set quantity of her mountain cheese every month. The café owner wants to pre-order 10 kilos of cheese for 500 francs and receive it in instalments over the coming months.

You'll find the five steps as an overview directly below this section. Here are the details for each step:

Step 1: Create the Main Invoice and Mark It as Paid

Lina opens Magic Heidi and creates a new invoice for the café. She adds one line item: "Cheese, 10 kg, 500 francs." She sends the invoice to the customer by email.

As soon as the 500 francs land in her account, she marks the invoice as "paid" in Magic Heidi. This step matters because it correctly records the revenue in her accounting. From a tax perspective, the transaction is complete at this point — even if the cheese is still physically sitting in the ageing cellar.

Step 2: Create a Second Invoice as a Running Credit

Now comes the trick. Lina creates a second invoice for the same customer. This invoice also contains "Cheese, 10 kg, 500 francs" — but it is not sent and not marked as paid.

This second invoice is Lina's internal inventory tool. In her financial dashboard, she now sees an open item of 500 francs, which reminds her: "I still owe this customer goods worth 500 francs."

Note: This invoice stays open for the entire delivery period. It's your counter-entry to the money you've already received.

Step 3: Create a Delivery Note for Each Partial Delivery

When Lina ships the first delivery of 2 kilos of cheese in May, she doesn't create a new invoice in Magic Heidi — she creates a delivery note. The delivery note contains just one line: "Cheese, 2 kg, 100 francs, delivery of 3 May."

She prints the delivery note and includes it with the package. She then reduces the quantity on her open "credit invoice" by 2 kilos, so it now shows only 8 kilos — or 400 francs — remaining.

At a glance she can see: "I've already delivered 100 francs' worth of cheese, and 400 francs are still outstanding."

Step 4: Document Deliveries Precisely

It's worth giving each delivery note a date or sequential label. Instead of just writing "Cheese", Lina writes "Cheese, delivery of 3 May" or "Cheese, delivery 1 of 5."

This way, even months later she knows which batch went out when. If the customer has questions or raises a complaint, the traceability is clearly documented.

Step 5: Close and Archive the Order

After several deliveries over the coming months, Lina ships the final 3 kilos of cheese in October. The "credit invoice" now shows 0 francs outstanding. She simply marks it as paid — or better yet, archives it.

What remains is the original paid main invoice for 500 francs in her accounting. The helper invoice disappears into the archive, and the whole process is cleanly wrapped up.

A Second Example: Wine Subscription for Restaurants

Let's look at how this works for a different use case. Picture Marc, a fictional wine merchant from the Lavaux on Lake Geneva. He has a small restaurant in Lausanne as a customer that, in January, orders a year's supply of 60 bottles of Chasselas for 1,800 francs — paid upfront.

Marc creates his main invoice for all 60 bottles, marks it as paid once the money arrives, and sets up the second credit invoice in parallel. Each month he delivers around 5 bottles to the restaurant and creates a delivery note with the corresponding quantity and delivery date.

In July, Marc can see at a glance: "I've delivered 30 bottles worth 900 francs. There are 30 bottles still outstanding." He doesn't need to maintain a spreadsheet, doesn't need to operate separate inventory software, and still has complete clarity. In December he delivers the last bottles, archives the credit invoice, and the process is done.

A Third Example: Coffee Bean Subscription for Offices

One final scenario to round things out. Say Sophie runs a fictional small-batch roastery in Zurich and supplies several co-working spaces with her coffee beans. A large office in Zurich West orders 15 kilos of beans per quarter for 750 francs and pays upfront.

Sophie uses exactly the same system: one paid main invoice, one open credit invoice for 15 kilos, and a delivery note for each of the three monthly deliveries of 5 kilos. After three months the order is fully delivered and the credit invoice goes into the archive.

Sophie's advantage: she can manage several customers like this simultaneously without losing track. Each customer has their own open credit invoice, and Sophie can see in her dashboard exactly how much stock each customer still has coming to them.

Common Pitfalls and How to Avoid Them

As simple as this system is, there are a few typical mistakes worth knowing about. You'll find the three most important ones as a compact overview below this section — here are the details:

Mistake 1: Accidentally Sending the Credit Invoice

You must never send the second, internal invoice to the customer. Otherwise they'll think they need to pay again. Magic Heidi lets you create invoices without sending them, so use that option consistently.

A good best practice: write something like "INTERNAL — do not send" in the internal notes or in the title of the helper invoice. That way you won't mix things up when you look at it later.

Mistake 2: Forgetting to Update Quantities

If you forget to reduce the outstanding quantity on the credit invoice after a delivery, your overview is off. Make it a routine: create the delivery note, print it, pack the goods, and update the credit invoice. Only then is the process complete.

Mistake 3: Booking It Incorrectly for Tax Purposes

Here's the most important point. The paid main invoice is your tax-relevant document. The credit invoice must not appear as a receivable in your official accounting — otherwise you have a double entry.

Magic Heidi helps here because archived invoices automatically disappear from active accounting reports. If you're unsure, get advice from a fiduciary or check out the Magic Heidi tutorials.

When Does This System Stop Being Enough?

Honestly: the approach described here is a pragmatic solution for simple cases. If you have more than 20 to 30 active delivery schedules running at the same time, manage lots of different items, or need to track real stock levels across multiple locations, you'll eventually need proper inventory management software.

But for the typical Swiss freelancer supplying a few regular customers with recurring deliveries, the Magic Heidi system is more than enough. You avoid expensive software, complicated onboarding, and still keep full control.

The Benefits of This Approach at a Glance

You'll find the key arguments for why this simple system makes sense for many freelancers as a summary directly below. These points are especially valuable if you're just starting out and don't want to invest in expensive tools yet.

Summary: Pragmatic Stock Management Without the Excel Chaos

Inventory management doesn't have to be complicated. By combining a paid main invoice, a running credit invoice, and individual delivery notes for each partial shipment, you have a lean system in Magic Heidi that works perfectly well for most freelancer scenarios.

The method works for cheese, wine, coffee, honey, handcrafted products, or any other goods you need to deliver in instalments over time. You don't need an Excel nightmare, expensive inventory software, or an accountant to set it all up. All you need is a clear system and the discipline to document each step properly.

Give it a try with the next customer who places a larger order spread over several months. You'll be surprised how much clarity you gain without having to learn anything new.