FAQ

This tool lets you attach, extract, and remove embedded files from PDF documents. It's ideal for handling PDF/A-3 e-invoices compliant with the ZUGFeRD standard. It can be used via the graphical interface (GUI) or through the command line (CLI).

In conjunction with our AI-supported service 7-PDF Invoice Extractor, the program, in addition to these standalone functions, also functions as an AI client. It communicates directly with the 7-PDF Invoice Extractor when converting PDF invoices into the ZUGFeRD PDF e-invoice format, and is responsible for the standard-compliant attachment of the important ZUGFeRD XML of the AI service.

Yes, starting from version 2.0! The tab "PDF Invoice to PDF ZUGFeRD" allows you to automatically analyze a standard PDF invoice using our 7-PDF Invoice Extractor. The AI identifies all relevant data and generates an XML file (factur-x.xml) according to EN 16931, which is then embedded into the PDF. Even scanned PDF invoices are read and supported by OCR recognition!

Only if your PDF invoice is not yet in PDF/A-3 format. In that case, you’ll need our 7-PDF Printer Professional to prepare it properly. This is often required in ERP print jobs or when generating PDFs from Word/Excel that include letterhead or embedded graphics.

After creating a PDF/A-3 invoice using 7-PDF Printer, 7-PDF Attach Extract and Remove is triggered automatically. There, the Invoice Extractor generates the ZUGFeRD XML file and embeds it into the PDF. This integration works through a print workflow and a simple command-line call with parameters.

See the step-by-step integration guide

The program runs on Windows 7 SP1 or later (32/64-bit) and is compatible with Windows 10, 11, and all major Windows Server versions. It works out of the box and requires no additional PDF software.

To use 7-PDF Attach Extract and Remove, a valid single or volume license is required (Named-User model). The integrated 7-PDF Invoice Extractor is included – along with 25 free conversions.

For higher volumes or long-term use, we recommend a monthly API subscription with token, which can be cancelled at any time.

If you plan to generate ZUGFeRD invoices via print workflow, you’ll also need a 7-PDF Printer Professional license. For structural validation, we recommend the 7-PDF E-Invoice Validator.

Yes. To ensure compatibility with recipient systems (e.g. government portals or accounting software), the embedded XML file must be named factur-x.xml. The tool handles this automatically for you.

Use our 7-PDF E-Invoice Validator to verify structure, syntax, and compliance with EN 16931.

Yes! You can use the command-line mode (-mode "console") with parameters such as -usage "attach" or "generate" to integrate it into PowerShell, batch scripts, or scheduled tasks.

In such cases, the Invoice Extractor may not generate XML, or only a partial one. Make sure your invoice includes key fields like recipient, IBAN, VAT ID, invoice date, and totals. These cases are logged internally.

Open the PDF in a viewer (e.g. Adobe Reader) and check the document properties. Under “Standards”, it should mention “PDF/A-3b”. Alternatively, you can use the 7-PDF E-Invoice Validator to confirm.

Yes. Use the CLI or a PowerShell/batch script to process complete folders automatically – ideal for incoming invoices from ERP, email, or scanner sources.

The API token you used is either expired (e.g. by canceling the subscription) or invalid. Please check your subscription or log in at https://generator.7-pdf.de/login to review your token and quota.

Yes. All data is transmitted exclusively via secure HTTPS (SSL/TLS) to our servers located in Germany. No unencrypted communication is used at any point.

Our AI-powered analysis platform was developed entirely in-house and runs on our own server infrastructure located in Germany.

Your PDF invoices and all associated content are immediately deleted after successful processing. No storage, logging, or transfer of data takes place.

7-PDF is a sole proprietorship based in Germany and operated under personal liability. We are not an anonymous GmbH or Ltd. As developer and operator, we personally stand behind quality, security, and data protection.

The 7-PDF Invoice Extractor can reliably process invoices with up to approximately 78 pages in practice. If OCR recognition is additionally required – for example, because important ZUGFeRD data is embedded in header or footer graphics – the maximum recommended number of pages is reduced by about half. This is mainly due to the typical limitations of OCR technology, rather than the performance of our AI service itself.

For best results, we therefore recommend using vector-based PDF invoices whenever possible. These are not only faster and more accurate to analyze but also significantly smaller in file size.

If the invoice text exceeds certain maximum limits, you will automatically receive a corresponding error message. Please avoid uploading very extensive documents (“half books”) in a single invoice.

Additional terms and conditions, service descriptions, or other invoice-related information can easily be attached separately to your ZUGFeRD PDF. Simply use our tool 7-PDF Attach Extract and Remove. This is exactly what the e-invoice standard and our service were designed for – keeping your invoices lean, compliant, and easy to process.

Avoid using incomplete or unsuitable documents. For your first tests, we recommend our free sample invoice. Follow the FAQs listed below and check whether your current invoice complies with all ZUGFeRD requirements in the current tax context.

If all else fails, wait a day or two as our AI service is constantly evolving. What doesn't work today doesn't have to fail again tomorrow. And "last but not least" - write to us using the support form. We appreciate any feedback!

For flawless extraction of your invoice data, it is important that all additional descriptions, notes or promotional texts are placed only after the actual invoice line items and totals in the PDF.

If such content is inserted before the invoice data, it can significantly impair automatic recognition or lead to incorrect results.

Therefore, please ensure that the structured invoice section is always at the beginning of the document and that optional texts, terms and conditions or supplementary information follow afterwards.

Or simply use 7-PDF Attach Extract and Remove to attach invoice-related documents such as terms and conditions, service descriptions or additional appendices to your ZUGFeRD PDF – that’s what the tool is designed for.

Only complete invoices with all mandatory details (line items, amounts, IBAN, VAT ID, etc.) can be processed. Missing information will result in an error message.

Important: A ZUGFeRD invoice must contain all mandatory information according to EN 16931 to be legally valid and to allow the 7-PDF Invoice Extractor to process the data correctly.

If mandatory fields are missing or incomplete, you will receive no valid output but an error message. Consistent and correct invoice data is absolutely essential. The principle applies: “Garbage In, Garbage Out” (GIGO).

A complete ZUGFeRD invoice must contain at least the following information:

• Invoice issuer (seller): name, address, VAT identification number or tax number, IBAN (optional BIC)
• Invoice recipient (buyer): name, address, VAT identification number if applicable (VAT ID of the buyer is mandatory (!) for reverse charge internationally and also nationally according to ZUGFeRD DIN EN 16931)
• Invoice data: unique invoice number, invoice date, delivery date or date of performance
• Line items: description of goods or services, quantity, unit of measure, net unit price, tax amount, tax rate, net amount per item
• Totals: net total, VAT per rate, gross total
• Payment terms: due date, discounts or payment period
• Special cases of tax exemption: clear statement of the reason (e.g., “Reverse Charge” or “Intra-community supply exempt from tax”)

Additionally required: All data must be available in the PDF as machine-readable text, not just as images. Our 7-PDF Invoice Extractor also supports OCR text recognition, but this is not always reliable!

Only if all mandatory fields are complete and plausible can the 7-PDF Invoice Extractor generate valid ZUGFeRD XML. Unfortunately, we cannot invent your invoice data 😉.

If your PDF does not contain machine-readable text (e.g., scanned invoices or pure image PDFs), text recognition (OCR) is necessary. Our 7-PDF Invoice Extractor automatically attempts to recognize the text in such cases. OCR is also required if important details (IBAN, VAT ID, tax number) are only present as an image in the header.

Tip: Check whether you can mark and copy text in the PDF. If not, it is an image PDF.

For deliveries or services to business customers in other EU member states, the so-called Reverse Charge procedure (§ 13b UStG) often applies. In this case, the VAT is reported by the recipient in the destination country.

Important requirements for the invoice issuer:

• The invoice must not include German VAT.
• It must contain a clear reference to Reverse Charge, e.g.:
  • “VAT liability of the recipient according to § 13b UStG”
  • “Reverse Charge – VAT reversed”
  • “Intra-community supply according to Art. 138 VAT Directive”
• The VAT IDs of both parties must be indicated (seller and buyer).

Example text on the invoice:
“Reverse Charge – VAT liability of the recipient according to § 13b UStG.”

Note: If applied correctly, only the net amount is shown. The tax obligation passes to the recipient.

For certain services between companies in Germany – for example construction work, metal deliveries, or scrap deliveries – the domestic Reverse Charge procedure according to § 13b UStG applies. In this case, the VAT is owed by the recipient.

Important notes for the invoice issuer:

• The invoice must not show VAT.
• It must contain a clear note, e.g.:
  • “VAT liability of the recipient according to § 13b UStG”
  • “Reverse Charge according to § 13b VAT Act”
  • “Construction services according to § 13b UStG”
• The VAT IDs of both parties must be indicated (seller and buyer).

Example text on the invoice:
“This is a construction service. VAT liability of the recipient according to § 13b UStG.”

Important: If this note is missing, the invoice is formally incorrect and will not be recognized as Reverse Charge.

If you operate under the small business regulation according to §19 UStG, your invoice must include a clear note, e.g. “According to §19 UStG, no VAT is charged.” Additionally, no VAT amounts may be stated. The 7-PDF Invoice Extractor automatically detects this if it is machine-readable in the text.

Important: Small businesses must also state a valid tax number or VAT ID in the invoice document.

For exports to non-EU countries, your invoice must state that it is a tax-exempt export delivery, e.g. “Tax-exempt export delivery according to §6 UStG”. No VAT amount may be shown. The 7-PDF Invoice Extractor automatically checks these statements and classifies the invoice correctly.

If such a note is missing, the tax exemption will not be recognized.

Yes, the 7-PDF Invoice Extractor also supports invoices with SEPA direct debit. However, the following information must be included in the invoice:

• Creditor ID (CreditorReferenceID)
• Mandate reference (DirectDebitMandateID)
• Debtor’s IBAN

If any of this information is missing, the payment method automatically defaults to “Bank Transfer.”

When generating the ZUGFeRD XML, the 7-PDF Invoice Extractor compares your invoice amounts with recalculated values. If the totals (e.g., overall amount) do not match plausibly, processing is stopped. This ensures compliance with EN 16931.

Always check: net totals, tax rates, discounts, and grand totals. Even minor rounding errors or incorrect discounts can cause rejection.

In principle, invoice line items must not have negative amounts. According to EN 16931, discounts or deductions must be shown in the invoice footer as Allowances, not as separate negative items.

An exception is commercial credit notes, where the quantity is shown as negative, but the net and gross prices remain positive. For more information, refer to the FAQ about commercial credit notes.

Important: Negative invoice line items are prohibited under DIN EN 16931. Percentage or total discounts must not be shown as lines with negative amounts.

Instead, such deductions must be declared in the invoice footer as SpecifiedTradeAllowanceCharge (overall discount).

Example of how this appears in the invoice:

In the XML, these deductions are represented as Allowances at document level. Each line item remains positive, and the deductions are recorded separately as total discounts.

Tip: Many accounting programs have dedicated fields for discounts or global deductions.

In the ZUGFeRD format, a commercial credit note can be represented. Technically, it is an invoice with negative amounts, but the calculation logic remains identical to a normal invoice.

At the line item level, gross and net prices as well as any surcharges or discounts are always shown as positive values. However, the quantity of the line item is negative. This combination automatically results in a negative line total. The following illustration shows an example.

The totals at document level therefore logically show negative amounts. It is also important that the header of the credit note includes the same payment terms as the original invoice. This will include a negative base amount (“BasisAmount”) and a negative discount amount (“ActualDiscountAmount”).

Important: For discounts to be correctly included in the ZUGFeRD XML, they must be clearly indicated.

The system processes line item discounts as follows:

• The original net unit price (list price) is recorded as the starting value.
• Discounts are shown as AppliedTradeAllowanceCharge within the item – not as a negative line item.
• If the total amount (quantity × price) is already discounted, the discount is not deducted again.
• The system automatically checks whether discounts are plausible. Inconsistencies trigger warnings or errors.

Note: Negative amounts in line items are not permitted under EN 16931. Always use the discount function instead.

Tip: If unsure, clearly state the net list price and the discount percentage. The system will calculate the reduced price automatically.

Only consistent details will result in a valid ZUGFeRD XML.

Important: If you are a doctor, alternative practitioner or therapist, you can invoice your services exempt from VAT according to §4 No. 14 UStG.

For the 7-PDF Invoice Extractor to correctly recognize your invoice as a tax-exempt medical treatment and generate the corresponding ZUGFeRD XML, the following criteria must be met:

• Seller and buyer are domiciled in Germany.
• The invoice contains a clear note about the tax exemption, e.g.: “VAT-exempt according to §4 No. 14 UStG”.
• No VAT is shown in the document.

The system automatically checks whether all requirements are met. If so, the XML will contain:

• A tax rate of 0%.
• The CategoryCode E (exempt).
• Your explanatory note as ExemptionReason.

Tip: If the tax exemption note is missing or vague, your invoice will not be recognized as tax-exempt medical treatment. Be sure to phrase it correctly.

Each invoice line item has a unit of measure, which is represented in the ZUGFeRD XML using a standardized UN/ECE Unit Code (e.g., H87 for pieces, LS for flat fee, MIN for minutes).

Typical examples:

• H87 – Piece (standard for goods)
• LS – Flat fee (e.g., shipping, one-off service)
• HUR – Hour (time-based services)
• MTR – Meter (e.g., cables, wires)

The system automatically detects these units based on the line descriptions. If no clear unit is found, H87 = Piece is used as fallback.

Tip: Check whether the unit logically matches the quantity (e.g., “10 meters of cable” ⇒ MTR).

Important: The ZUGFeRD format (according to DIN EN 16931) only allows a strictly defined set of units from the international standard UNECE Rec 20. Not all conceivable or industry-specific units are permitted. For example, exotic codes such as "EA" (Each), "PK" (Pack), or "PAR" (Pair) are not accepted in ZUGFeRD.

Some suppliers specify prices not per piece but e.g., “per 100 pieces” or “per 1,000 pieces.” This can appear as if the unit price is incorrect.

Example from the invoice:

In this case, the system automatically divides the price by 100, so that the unit_price is correctly recorded as 0.0813 € per piece. This ensures correct validation later.

Reminder: If you see price discrepancies, check whether “per 100 pieces” or “per 1,000 pieces” is indicated. The unit price is then recalculated automatically.

Yes. If you invoice services or time units (e.g., working hours), you should clearly indicate in your invoice:

• Quantity (e.g., 3 hours)
• Unit (e.g., hour – HUR)
• Unit price

The system then automatically assigns the correct unit and calculates the total price.

Example:

Tip: Always check that the quantity and unit are consistent.

Flat amounts such as shipping, postage, packaging, or one-off services are always represented in the ZUGFeRD invoice as separate line items with the unit LS (lump sum).

Example invoice:

This results in two line items:

• Line 1: Goods (H87 – piece)
• Line 2: Shipping costs (LS – lump sum)

Tip: Always specify shipping costs explicitly in the invoice to ensure correct representation and validation.

Many suppliers list additional surcharges (e.g., copper, raw material, energy) directly under the main line items. In the ZUGFeRD XML, they are automatically assigned as surcharges to the relevant line item.

Example:

The result is a surcharge recorded with its type and amount, ensuring a transparent and machine-readable invoice.

Reminder: Surcharges are never separate line items but always linked directly to a main item.

Some invoices contain free items such as catalogues, samples, or promotional materials. These are listed with a price of 0.00 €.

Important: Even if the price is 0.00 €, a VAT rate must be specified. If no specific VAT rate is stated, the invoice’s overall VAT rate (e.g., 19% in Germany) is applied.

Example line item:
Catalogue – Quantity: 1 – Unit: Piece – Unit price: 0.00 € – VAT: 19%

Tip: Always list free items separately to avoid questions later.

Some invoices explicitly state that a discount is included, e.g., “incl. 25% discount.” This means the price has already been reduced.

Example:

In this case, no additional discount value is recorded. The unit price remains as stated, and the discount percentage is recorded as 0.0%.

Tip: Always check whether the discount has already been factored in before entering data.

Farmers and forestry businesses may apply the so-called flat-rate VAT scheme under § 24 UStG. This scheme provides a flat-rate VAT calculation.

Important change starting 2025:
According to the German government’s announcement (Drucksache 20/11920, hib no. 460/2024), the flat VAT rate will be 7.8% from 01.01.2025 (previously 9.0%).

Example agricultural invoice (fictitious values):

Net amount: 271.00 €
7.8% VAT: 21.14 €
Total amount: 292.14 €

When processed with the 7-PDF Invoice Extractor:

• The VAT rate must appear clearly in the PDF invoice text (e.g., “7.8% VAT”).
• The ZUGFeRD XML automatically takes this value from the detected content.
• If the rate is missing or unclear, the XML will be incomplete or erroneous.

Important: Please carefully check that the stated VAT and all mandatory details are complete and plausible before converting to ZUGFeRD.

Note: The flat-rate VAT scheme can only be applied if your business meets the conditions of § 24 UStG. If in doubt, consult your tax advisor.