PZN (Pharmazentralnummer)

PZN stands for Pharmazentralnummer, the nationally uniform identification key for medicines and other pharmacy goods in Germany. It is an eight-digit number including a check digit, assigned by the IFA GmbH, and it works as the agreed key to trade name, manufacturer, pharmaceutical form, strength and pack size.

That definition is not a convention that grew up informally. It is contractual. The framework agreement under section 131 SGB V, concluded between the GKV-Spitzenverband and the federal associations of pharmaceutical companies, states in its section 2 that the nationally uniform identifier required by section 300 paragraph 3 sentence 1 no. 1 SGB V is the Pharmazentralnummer, and it defines that identifier as the unique key to trade name, manufacturer, pharmaceutical form, strength, pack size and further price and product information.

The PZN is deliberately non-speaking. No digit encodes a manufacturer, a substance class or a pack size. It is a neutral pointer, and everything a professional actually wants to know sits in the databases the number points into. That is the whole design: one short number, agreed by every market side, that resolves to the same product for the pharmaceutical company, the wholesaler, the pharmacy and the health insurer. The IFA GmbH assigns it on application by the pharmaceutical company, on the basis of a supplier contract concluded between the two.

How is the PZN structured, and how is the check digit calculated?

Since 1 January 2013 PZN are issued with eight digits. PZN that carried seven digits up to 31 December 2012 were extended to eight with a leading zero and remain valid. Leading zeros are therefore part of the code and must never be trimmed, which is the single most common integration bug when PZN are moved through spreadsheets or loosely typed database columns.

The last of the eight digits is a check digit, calculated from the seven preceding digits using a modulo 11 procedure. The calculation is short enough to implement in any language in a few lines:

1. Take the seven information digits of the PZN, in order.
2. Weight them with the factors 1 to 7, so the first digit is multiplied by 1, the second by 2, and so on to the seventh, which is multiplied by 7.
3. Add the seven products together to get a sum.
4. Divide the sum by 11 and keep the integer remainder.
5. That remainder is the check digit, and it becomes the eighth digit.
6. If the remainder is 10, the digit sequence is not used as a PZN at all. This is why a naive implementation that maps a remainder of 10 to 0 or to X will silently accept numbers that IFA never issued.

The worked example published by IFA uses the information digits 2758089:

The seven products add up to 174. Dividing 174 by 11 gives 15 remainder 9, so the check digit is 9 and the complete PZN is 27580899. The purpose of the check digit is narrow and practical: it catches mistyped and misscanned numbers at the point of order entry, before a wrong pack is picked or a wrong article is billed.

How does the PZN differ from the PPN, the NTIN and the GTIN?

This is the distinction that costs integration teams the most time, because all four identifiers can appear on the same carton and three of them contain the PZN. They are not competing schemes. They are wrappers at different scopes.

The PPN mechanism is worth understanding, because it is what makes a purely German number usable abroad without changing it. IFA assigns, as an Issuing Agency, a Product Registration Agency code (PRA code) to each national pharmaceutical numbering system. Putting that PRA code in front of any national product number makes the result globally unambiguous. For the German market the PRA code is 11, so a PZN of 03752864 becomes the PPN 110375286414: the prefix 11, the eight PZN digits, and the two-digit check digit 14 calculated with modulo 97 over the ASCII values of the string. The PZN is not replaced. It is carried inside.

The NTIN does the same job through the GS1 system instead: it embeds the PZN in a GTIN structure. Because the resulting number is only valid nationally, it is called a National Trade Item Number rather than a GTIN, even though it is formatted like one.

Where is the PZN legally required?

The PZN is not named in any statute. The statutes require a nationally uniform identifier and delegate the choice of it to the framework agreement, which then names the PZN. Knowing this two-step is what lets you answer the question "where is this actually written down" correctly.

That last row explains a question German integrators ask constantly. Because the PZN already sits inside the product code, whether that code is a PPN or an NTIN, Germany does not require the PZN again as a separate fifth element in the Data Matrix. IFA notes one exception: multi market packs, where the PZN is not contained in the product code, must carry it as a fifth element.

How is the PZN encoded on the pack?

Here the common answer is out of date, and it is worth being precise. For decades the PZN travelled in a Code 39 barcode. The framework agreement specifies that encoding in line with ISO/IEC 16388, with the asterisk as start and stop character and a hyphen in front of the digits as the PZN identifier under ISO/IEC 15418, giving the familiar pattern of an asterisk, a hyphen, eight digits and a closing asterisk.

What changed is the obligation. Under Delegated Regulation (EU) 2016/161 the Data Matrix code became binding for all verification-relevant medicines on 9 February 2019. The framework agreement had required the Code 39 barcode additionally only until that date. Since then, IFA states that the PZN is applied in plain text with the short prefix "PZN:" and without the Code 39 barcode, while the machine-readable path runs through the Data Matrix, where the PZN is carried inside the PPN or the NTIN alongside serial number, batch and expiry date.

So a pack produced today will usually still show a PZN you can read with your eyes, but the barcode your scanner reads is a Data Matrix, and the PZN comes out of it wrapped. Systems that only know how to parse a Code 39 PZN are reading a carrier that is no longer required to be there.

Where do professionals find the PZN on pharmazie.com?

On pharmazie.com the PZN is not one field among many. It is the primary key across all connected databases, which is what makes a single search resolve an article, its prices, its legal status, its supply shortage record and its documents at once. The neighbouring identifiers sit directly beside it in the article base data.

• Field: PZN as primary key across all connected databases; article base data carrying PPN, NTIN, GTIN and UDI-DI
• Granularity: per PZN
• Source: ABDA article master data (ABDATA Pharma-Daten-Service)
• Updated: daily, with a source and date stamp on every detail page
• Access: web app, REST API, data export

One honest limitation: pharmazie.com is not the assigning body and not an IFA data outlet. A PZN exists because IFA issued it, and if what you need is the IFA information service itself, in its original delivery format and on its own publication rhythm, that is a licence you take out at the source. What an aggregator adds is not the number. It is everything the number resolves to.

Sources

• IFA GmbH: Technische Hinweise zur PZN-Codierung, Prüfziffernberechnungen der PZN, PPN und Basic UDI-DI
• GKV-Spitzenverband: Rahmenvertrag nach Paragraf 131 SGB V, Fassung vom 26. März 2018
• Paragraf 300 SGB V: Abrechnung der Apotheken und weiterer Stellen
• Paragraf 131 SGB V: Rahmenverträge mit pharmazeutischen Unternehmern
• IFA GmbH: FAQ zur Pharmazentralnummer und zum Data Matrix Code