From Excel to SaaS: the complete migration guide for installation companies

Many installation companies considering Koldwerk currently still work with a combination of Excel, Outlook, paper folders and (for the lucky ones) an accounting package. The step to a dedicated SaaS platform often feels big — not just technically, but organisationally too. "We'll have to re-enter all the installations", "My technicians aren't that digital", "What if something goes wrong during the transition?"

These are legitimate concerns. They're also solvable — if you do a structured migration instead of an ad-hoc start. This guide describes the approach that works in practice.

Phase 1: Inventory (1-2 weeks)

Before you migrate anything, you map out what you have. This is the phase that gets skipped most often — and most often the phase that derails the rest of the migration.

### What do you collect?

• Customer file. Name, KvK number, invoice address, contact person, email, phone, VAT number.
• Installation file. Per installation: site address, make, type, serial number, installation date, refrigerant type, refrigerant charge in kg, owner (= customer).
• Maintenance contracts. Per contract: customer, installation(s), term, frequency (e.g. 1×/year), price.
• Open work orders. Work orders that haven't been invoiced yet — you don't want to lose those during migration.
• Cylinder stock. Per cylinder: ID, empty weight, current contents, refrigerant type, location (office / technician's van).
• Technician certificates. Per technician: personal certificate (BRL 200), expiry date, scan.

In practice this is the bulk of the work. Start with your top 100 most important customers (the 80/20 rule: you'll find that 20% of your customers generate 80% of your revenue). Migrate those correctly first; the rest can follow in a second round.

### Quality check

Before you import anything: have one assistant or intern cross-check the data:

• Are all KvK numbers listed in the Handelsregister?
• Is the installation ↔ customer relationship correct in every case?
• Are there duplicates (same customer under two names)?

Data clutter that was in your old Excel file carries straight over into your new system if you don't clean it up first. Migration is an ideal moment to do that.

Phase 2: Setting up the platform (1 week)

With Koldwerk you do this yourself via /aanmelden:

1. Create your workspace (5 min). 2. Enter company details — KvK, VAT, invoice address, logo (10 min). 3. Accounting link: enter your Debitan credentials if you use that (15 min). 4. Customise your work order template: colours, logo, footer text (30 min). 5. Invite your first two technicians for the trial phase (5 min).

Allow a half-day to do this properly. Don't start at 4pm on a Friday.

Phase 3: Data import (1-2 weeks)

Koldwerk has an import tool that reads CSV/Excel files. Per data type:

### Customers Format the CSV with columns: `naam, kvknummer, adres, postcode, plaats, contactpersoon, email, telefoon, btwnummer`. Upload, check the preview, confirm.

Note: duplicate detection is based on KvK number. Customers without a KvK number (sole traders (ZZP), private individuals) are matched on name only.

### Installations Format the CSV with: `klantkvk, locatieadres, merk, type, serienummer, plaatsingsdatum, koudemiddel, koudemiddel_kg`.

For the refrigerant type: use the exact name (R-32, R-410A, R-454B, R-1234yf, R-744). The importer warns for unrecognised types.

### Technicians Via /gebruikers manually, or via CSV with: `naam, email, brl200nummer, brl200verloop`.

Every technician receives a sign-up email. Prepare them for this — don't send it out of the blue.

Phase 4: Trial work orders (2-4 weeks)

This is where the tension lies. Don't migrate all technicians at once — pick 2-3 experienced technicians and run a double administration for 2-4 weeks:

• They fill in work orders in Koldwerk.
• They keep up their normal paper/Excel flow at the same time.

At the end of every week: compare what's in Koldwerk with the paper/Excel flow. Do any work orders differ? Is information missing? This is cheap error detection — fix the gaps before you roll out broadly.

Our experience: after 2-3 weeks technicians find it annoying to do double administration, and they want either paper only or digital only. That's a good signal — switch over.

Phase 5: Full rollout (1 week)

Once the trial has succeeded:

1. Schedule an office meeting with all technicians (like one about their favourite topic: coffee and refrigeration technology). 2. Have a trial technician demonstrate the flow — not you, not the software vendor. Peer-to-peer. 3. Give everyone 30 minutes to practise themselves. 4. Declare paper stops from tomorrow 08:00: new work orders only via Koldwerk.

The first week is messy. Expect 10-20% of the work orders to raise questions. Plan for yourself — or a colleague — to be available for quick questions via WhatsApp.

Phase 6: Backlog administration (2-4 weeks)

Before go-live you had a paper backlog: old work orders still to be invoiced, old refrigerant changes, old leak checks. Schedule a dedicated office employee (or yourself) 2-4 weeks after go-live to enter that backlog.

Do this with realistic expectations: one person can key in 30-60 work orders a day, provided they already have the paper filled in. Plan that into a calendar with deadlines.

Common mistakes

1. Wanting to go too fast.

Wanting to migrate in a week is almost a guarantee of frustration. Allow 6-10 weeks for a 5-technician company.

2. Too little training.

One Zoom call isn't enough. Schedule a follow-up session after week 1, and another after week 4. People forget things or discover new sticking points.

3. No back-out plan.

What if it really doesn't work? Keep your paper flow on standby for the first 2 months. Not to go back to it, but to build confidence that you're not stuck.

4. Not thinking about the accounting.

New work orders go via Koldwerk to Debitan. But old work orders still sitting in another package — how do you close those off? Schedule a closing point per quarter, and link the accounting data there.

5. Not measuring.

Before the migration, establish 3 baseline figures:

• Time per work order (in minutes of administration)
• % of work orders lost
• Turnaround time from work order to invoice

Measure those figures again 3 months after go-live. That's your ROI proof.

Need help?

For companies with >10 technicians or complex historical data: our Enterprise package includes dedicated migration support. A Koldwerk engineer does the inventory together with you and makes sure the imports are correct before go-live.

For smaller companies: all the steps above are deliberately do-it-yourself. Questions along the way? Get in touch — we reply by email within one working day.

Or compare your migration options via Koldwerk vs Excel + paper — a fair side-by-side of what you're trading for what.

Disclaimer: This guide describes a typical migration. Companies with significantly different workflows (for example refrigerated transport with ATP inspections, or installers with their own ERP system) may need specific adjustments. Request a free migration consultation via /contact.