e-Invoice Dates: How to Fill Them Out Correctly?

Have you ever paused with your mouse hovering over the date fields in the app, wondering: “Which exact date should I put here, and how is it connected to the others?”

With the arrival of Fiscalization 2.0 and mandatory e-invoices, dates are no longer just a formality. They are data that the Tax Administration’s system and your buyer’s accounting software read automatically. A wrong delivery date can mean an incorrect VAT calculation, and a wrong due date can disrupt your billing.
In this guide, we demystify the “big four” dates: Date of Issue, Date of Delivery, Accounting Period, and Due Date.

1. Date of Issue: The Moment of Creation

This is the date when you created and finalized the invoice in our app.

• What does it mean?
  The official date the document was created. The payment deadline (due date) is usually calculated from this date
• Important for our app: Even if you click “Send to Information Intermediary” a day or two later, the XML file (e-invoice) will contain the date when you formed and finalized the document.
  

2. Date of Delivery: The Moment of Tax Liability

From a tax perspective, this is the most important date for the state. It dictates which month this invoice falls into for VAT calculation.

• What does it mean?
  The day the service was performed, the goods were delivered, or the accounting period ended (e.g., end of the month).
• The Rule: If the Date of Delivery is Jan 31st, the VAT goes into January, even if you issued and sent the invoice in February.
  

Note: e-Invoice generation apps should allow entering a future delivery date in these cases:

• Construction situations: Temporary situations are issued for works that will be formally accepted on a specific date.
• Subscriptions and rentals: Issuing an invoice in the current month for a service related to the next month.
• Advance invoices (Prepayments): Although for advance payments the delivery date is actually the date the money is received, a future period is sometimes defined in the description.
  

3. Accounting Period (FROM – TO): Description of the Service

This describes “the time period to which this item relates.” It is crucial for continuous services (rent, maintenance, subscriptions).

• Period FROM: The start of service provision.
• Period TO: The end of service provision.

Note:

• The FROM-TO period can be outside (in the past).
• The FROM-TO period can be outside (in the future) of the delivery date.
• The most common case is when the “Period TO” date equals the Date of Delivery.

Examples:

4. Due Date: When Must the Money Arrive?

This is commercially the most important date for you. It defines the deadline by which the buyer must settle the debt.

• What does it mean?
  The last day for payment.
• How is it determined? Usually calculated as Date of Issue + Number of delay days (e.g., 15 or 30 days).

In the eInvoice: The buyer’s software uses this date to automatically schedule the payment order in their internet banking.

THE BIG CHEAT SHEET: The Interrelation of All Dates

This is where most questions arise. How are all these dates connected? Can the due date be before delivery? Here is the logic for the most common scenarios:

Scenario A: Invoice for the previous month (e.g., Services or Rent)

You worked all of January, and you are preparing the invoice in early February.

1. Accounting Period: 01.01. – 31.01. (Describes what you did).
2. Date of Delivery: 31.01. (Follows the end of the period – VAT goes to January).
3. Date of Issue: 02.02. (Today, when you are physically making the invoice).
4. Due Date: 17.02. (e.g., Date of issue + 15 days).

Watch out: The payment term runs from the date of issue, not delivery (unless defined otherwise by contract).

Scenario B: Sale of goods (Immediate delivery)

You delivered the goods today and are making the invoice immediately.

1. Accounting period: Not strictly necessary (or is today’s date).
2. Date of delivery: 25.01. (Today).
3. Date of Issue: 25.01. (Today).
4. Due Date: 25.01. (If it’s an immediate transactional payment) or later 09.02. (if you grant a 15-day delay).

Scenario C: Upfront payment (Advance or Subscription)

You are sending an invoice today for next month’s rent.

1. Accounting Period: 01.02. – 28.02. (The future).
2. Date of Issue: 25.01. (Today).
3. Date of Delivery: 25.01. (The moment of issuing the invoice for a future service).
4. Due Date: 31.01. or 01.02. (Usually, you require payment before the service usage begins).

How Does Our App Help You with Date Math?

Since sending the invoice to the information intermediary happens after creation, our app ensures that all dates are aligned and logical before you click “Send”.

Here is how we automate the process for you:

1. Link Period >Delivery: If you enter “Period TO” (e.g., 31.01.), the app recognizes this is likely your Delivery Date and suggests this entry so your VAT is correct.
   
2. Final Check: Before sending the invoice to the intermediary, you have a clear overview of all 4 dates.
   

Remember: The information intermediary is just the “postman” – they transmit exactly the dates you defined. Our app is your “air traffic controller” making sure the dates don’t crash!

Still have doubts?

Reach out to our support – we are here to keep your invoices accurate and your payments on time!