E-invoicing 2027 for accounting firms: what is changing and how to handle it with Invoice Manager
Blog
Find out how electronic invoicing starting in 2027 will change the work of accounting firms, what obligations electronic invoices will bring, and how sending and receiving them via the Peppol network works. Read about how to prepare for e-invoicing 2027 with the QASIDA Invoice Manager solution.
E-invoicing 2027 for accounting firms: what is changing and how to handle it with Invoice Manager
Blog
Find out how electronic invoicing starting in 2027 will change the work of accounting firms, what obligations electronic invoices will bring, and how sending and receiving them via the Peppol network works. Read about how to prepare for e-invoicing 2027 with the QASIDA Invoice Manager solution.
Date: 13.11.2026
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Posted by: Erika Fülöpová
What Awaits Accounting Firms in Connection with E-Invoicing? What Does E-Invoicing Change and How to Handle It with Invoice Manager
From 1 January 2027, the way companies in Slovakia send invoices will change. A PDF sent by email will no longer be sufficient and will be replaced by a structured XML file delivered through a digital postman in the Peppol network. For accounting firms, this does not mean just a new obligation. It changes where documents come from, how they are checked, archived and corrected, and what you need to agree on with each client.
This article explains what is changing for accountants, what the Financial Administration says about it, and how the accounting system QASIDA Invoice Manager by Asseco Solutions addresses these changes. This solution, designed for accounting firms and small sole traders, already supports connection to a digital postman, invoice configuration for electronic invoicing, and document validation before sending.
What will you learn in this article?
- VAT payers must issue electronic invoices, while all entrepreneurs and legal entities must be able to receive them.
- Each client has their own digital postman for receiving invoices. The accountant can be granted access to the client's mailbox.
- If an accountant is to perform actions on the Financial Administration portal on behalf of a client, they need authorization to act as a representative.
- Responsibility for the accuracy of the information and the timely issuance of an invoice remains with the supplier, even if the document is created by the accountant.
- Invoice Manager connects to the digital postman once, after which it sends and receives invoices via Peppol.
What Is Changing in the Work of an Accounting Firm
The biggest change takes place at the input stage: documents will no longer arrive as PDFs, scans and emails, but as structured data through the client's digital postman.
| Today | From 1 January 2027 | |
|---|---|---|
| Document receipt | PDF, scan, email, paper | XML via the client's digital postman |
| Data entry | Manual or via OCR | Automatic import into the software |
| Archiving | Often PDF only | Original XML file, 10 years |
| Invoice correction | Corrective invoice or cancellation | Credit note and a new invoice, or a corrective invoice – referencing the original invoice |
| Compliance checks | Visual inspection | Validation when sending and receiving; correct completion of fields is decisive |
| Reporting to the Financial Administration | VAT control statement and recapitulative statement | The VAT control statement will be submitted until 30 June 2030; the postman will also report invoice data |
What does e-invoicing not change? The mandatory invoice requirements under Section 74 of the VAT Act, the 15-day deadline for issuing and sending an invoice, and the accountant's obligation to assess the content of the document. The format and delivery method are changing.
What changes and what is added with e-invoicing? Each client must have a contracted digital postman. For receiving invoices, they can have only one, while for sending invoices they can have several. An invoice that is required to be issued as an e-invoice must be handed over to the postman so that the issue date matches the sending date. Simply creating it in the software is not enough.
What does the new invoicing system not allow? An invoice that has been sent cannot be deleted or rejected through Peppol. Errors are resolved by issuing a credit note and a new invoice, which is why checking the document before sending is important.
Working with Clients: What Needs to Be Agreed
The Financial Administration has provided specific guidance on cooperation with external accountants. The following points should be agreed on with each client in advance.
Access to invoices. Each client will have their own postman for receiving invoices, but they can grant the accountant access to their mailbox. Depending on the capabilities of the specific solution, documents from multiple companies can be handled in one environment, with different access permissions configured.
Authorization on the portal. If the accountant is also expected to perform actions on the Financial Administration portal on behalf of the client, such as selecting a digital postman, they must have the appropriate authorization to act as a representative. Without it, the client must select the postman themselves.
Issuing invoices on behalf of the client. The accountant can issue and send invoices in the client's name. However, system access and the processing procedure must be agreed on in advance. Responsibility for the accuracy of the information and the timely issuance of the invoice remains with the supplier, i.e. the client, even if the document is created by a third party.
What will not be automated. The new system does not mean that invoices will be posted without human intervention. The accountant will still assess the content, accuracy of the information, accruals and allocation of expenses. Information known only to the client (whether the goods were actually received, which cost centre an expense belongs to) must still be communicated between both parties.
What to agree on before 1 January 2027:
- who will select the postman and who has authorization on the portal,
- who issues invoices: the client or the accountant on their behalf,
- who has access to which documents and with what permissions,
- who approves and pays invoices,
- who archives XML files (10 years) and where.
How Invoice Manager Addresses These Needs and What It Is Used For
QASIDA Invoice Manager by Asseco Solutions is designed for accounting firms and small sole traders. Below is an overview of what an accounting firm needs for e-invoicing and where to find it in the application.
| What You Need | How Invoice Manager Handles It |
|---|---|
| Connection to a digital postman | One-time connection to the APEX postman in the Synchronization section. After that, e-invoices are sent and received via Peppol. |
| Deciding which invoices are sent via Peppol | Each type of sales invoice has the option “Send to Peppol” (for the Invoice and Invoice for Received Payment types). |
| E-invoice codes | The “E-invoice code” field for the unit of measurement, payment method and VAT rate. |
| Different document types | Invoice, advance invoice, invoice for received payment, credit note, settlement invoice and credit note for an invoice for received payment. |
| Document numbering | Numbering sequences by invoice type, for example in the format year, month and sequence number. |
| Pre-send validation | Workflow with the Check Mandatory Data and Close Invoice actions. |
| Corrections | A credit note with a reference to the original invoice number in the template. |
| Access and responsibilities | Users, roles and workflow roles, assignment of the responsible user when the status changes. |
| Client communication | Email and document templates containing client details, a QR code and PayBySquare. |
One-time connection and Peppol box. The connection to the APEX digital postman only needs to be set up once. The condition is that the company has selected a postman on the Financial Administration portal. You can select us as your postman HERE. Electronic invoice management is available in the main menu under the Peppol box section.
Pre-send validation. Since an invoice that has been sent cannot be deleted through Peppol, checking it before sending is essential. The workflow in the application uses the statuses To do, In progress and Done. Actions can be assigned to these statuses: assign a user, check mandatory data, close the invoice (the header and line items become non-editable), or unlock it by providing a reason. For an accounting firm, this is a practical way to distribute work among employees and enforce a check before closing a document.
Roles and users. You can set a role and access level for each user, for example Administrator, Manager or Employee. Workflow roles determine who can change document statuses. This makes it possible to agree with the client on who issues, checks and closes documents.
E-invoice codes. For an e-invoice, each line must have a unit of measurement expressed using a code from the UN/ECE code list, and the invoice must contain correctly identified VAT rates. The administrator enters these codes in the code lists, and documents then inherit them.
Document types and corrections. The templates support invoices, credit notes, advance invoices, invoices for received payments and settlement invoices. A credit note contains the original invoice number, which corresponds to the recommended procedure for corrections in Peppol: a credit note and a new, correct invoice.
Checklist for Accounting Firms by 31 December 2026
Conclusion
E-invoicing does not change what an accountant does. It changes how documents reach them and how they are sent. The biggest risk is not the technology itself, but failing to agree on access, responsibilities and the postman with clients in time. When configured correctly, e-invoicing reduces manual data entry and provides cleaner data and validation before sending.
Invoice Manager helps you connect to a digital postman, configure documents for Peppol and distribute work within your team. If you would like to see how it works in your environment, get in touch with us and we will prepare a demonstration for you.
Disclaimer. This article is for informational purposes only. The legal information is based on a document issued by the Financial Directorate of the Slovak Republic and statements made by its spokesperson. Information about Invoice Manager is based on the application's administrator manual (as of 29 October 2026). Features and procedures may change; always refer to the current documentation. For specific cases, consult a tax advisor or the tax administrator.