How to prepare for e-invoicing step by step – a concrete implementation plan

From previous blogs, you know what is changing. You know how it works. Now comes the most important part: How to actually prepare for e-invoicing – step by step?

Because the difference between a smooth transition and chaos at the end of the year just before e-invoicing becomes mandatory lies in proper preparation.

🧭 Step 1: Analyze how you operate today

Start from your company’s real day-to-day processes.

Map out:

• how you issue invoices
• how approval workflows work
• how invoices are sent
• how you receive supplier invoices
• how accounting is processed
• where and how you archive documents

👉 The goal is to understand which areas need to be adjusted or changed.

🔍 Step 2: Identify weak points

After the analysis, ask key questions:

• where do errors occur today?
• where is data manually retyped?
• where do delays happen?
• which processes depend on specific individuals?

👉 These are exactly the areas where e-invoicing will bring the greatest improvement.

🧾 Step 3: Clean up your data

This is one of the most underestimated steps.

Check:

• company IDs, VAT IDs and tax IDs of business partners
• addresses
• duplicates in your database
• correctness of identifiers

👉 In e-invoicing, the rule applies: poor data = undelivered invoice

💻 Step 4: Prepare your system (ERP/accounting system)

Verify whether your system:

• can generate e-invoices in XML format
• supports the required standard
• allows receiving e-invoices
• handles automated processing

👉 If it does not meet these requirements, you will need to consider:

• upgrading the existing system
• implementing a new module
• or using an external solution

🔗 Step 5: Ensure infrastructure connectivity

Without this part, e-invoicing will not work.

You need to ensure:

• a digital “postman” (Access Point)
• access to the PEPPOL network via this postman
• correct configuration of identifiers

👉 This is the most technically demanding part of implementation.

🧪 Step 6: Test (thoroughly)

Before going live, the entire process must be thoroughly tested:

• test invoice issuance
• test invoice sending
• test invoice reception
• verify accounting accuracy
• test together with business partners

👉 A pilot operation before full rollout is the ideal approach.

👥 Step 7: Prepare people and processes

Technology alone is not enough – people and processes play a key role.

You need to:

• train the accounting department
• update internal policies
• set approval workflows
• inform business partners

👉 Employees must clearly understand what is changing and how it affects them.

🚀 Go-live deployment

After testing, the live deployment follows:

• launch production operation
• monitor processes continuously
• resolve issues
• fine-tune details

👉 The first weeks are critical for stabilizing the solution.

⚠️ How much time to allocate

Best practice recommendation: start at least 6 months before the mandatory deadline. According to current information, a pilot phase should be available approximately 3 to 6 months before go-live, allowing time for testing and adjustments.

Why starting early matters:

• integrations take time
• testing reveals potential issues
• employees need time to adapt

🚀 How to significantly simplify it

This entire plan may seem complex. And it is – if you build it from scratch.

However, the QASIDA system from Asseco Solutions can significantly simplify several steps at once:

🔧 Technical readiness

• generates e-invoices in the correct XML format
• ensures data validation
• handles PEPPOL connectivity and the digital “postman”

🔗 Integration

• e-invoicing is a native part of the Qasida ERP system
• enables automated sending and receiving of invoices within a single system
• ensures unified data processing without external integrations

⚙️ Implementation

• shortens implementation time
• reduces error risk
• eliminates the need to solve technical details

👉 In practice, this means the company implements a ready-made and proven system instead of building a solution from scratch.

💡 Reality: prepared vs. unprepared company

Unprepared company:

• solves problems at the last minute
• has poor or incomplete data
• does not have time for testing and process tuning

Prepared company:

• has clearly defined processes
• uses a system that works automatically
• manages the transition to e-invoicing smoothly and without complications

Prepare for e-invoicing correctly and on time with expert support from Asseco Solutions

👉 What comes next?

Now you have a concrete plan on how to prepare. In the next part, we will look at The most common mistakes in e-invoicing and how to avoid them.

If you want to switch to e-invoicing without stress, the best approach is to start now – ideally with a solution that covers both technology and processes in one.