Product teams use "barcode", "QR code", "GTIN" and "serial number" as if they were interchangeable. They are not, and mixing them up leads to real mistakes: buying "barcodes" when you need numbers, printing a QR code no checkout can use, or assuming a code proves a product is genuine. This guide separates the four ideas.
The short answer: three different questions
Each term answers a different question about a product.
| Question | Answered by | Example |
|---|---|---|
| What product is this? | An identifier: the GTIN | 09501101530003, meaning Maison Ardent Ambre Nuit 100 ml |
| How does a machine read it? | A data carrier: a barcode or QR code | An EAN-13 barcode, a GS1 DataMatrix, a QR code |
| Which individual one is it? | A serial number, used with the GTIN | Serial A7K29Q on one specific bottle |
The number is the identity. The symbol is just packaging for the number. Keeping those apart makes the rest straightforward.
The GTIN: an identifier for a product type
A GTIN (Global Trade Item Number) names a kind of product: one size, flavour or variant. Every identical 100 ml bottle of Ambre Nuit has the same GTIN. You create GTINs from your GS1 Company Prefix, and retailers use them as the key to their own product, price and stock records.
A GTIN is just digits. You could write it on an invoice, type it into a spreadsheet or say it over the phone, and it would still identify the product. More on this in what is a GTIN and why does it matter?
The barcode or QR code: a carrier
A barcode is a way of printing data so a scanner can read it quickly and reliably. It is the carrier, not the identity. GS1 standards specify which carriers to use where, and how to put GS1 data inside them.
Data carriers compared
| Carrier | What it holds | Who reads it | Typical use | Opens on a phone? |
|---|---|---|---|---|
| Linear barcode (EAN-13 / UPC-A) | GTIN only | Laser and imaging scanners at checkout | Retail checkout today; nearly universal | Not useful to consumers |
| Plain QR code | Any text, usually a web address | Phones; not interpreted as a product by POS | Marketing links, campaigns | Yes — opens a web page |
| QR code with GS1 Digital Link | A web address that contains the GTIN and optional batch, serial, expiry | Phones, and 2D-capable POS scanners that extract the GTIN | Consumer-facing packs that also need to scan at checkout | Yes — resolves to brand content |
| GS1 DataMatrix | GS1 element string: GTIN plus batch, serial, expiry and more | 2D imaging scanners; most phone camera apps will not open it | Healthcare, regulated and small packs, industrial marking | Usually not, without a dedicated app |
The comparison above shows the main carriers you will meet on packs:
- Linear barcodes (1D), such as EAN-13 and UPC-A. They hold just the GTIN, can be read by almost every retail scanner today, and have no room for much else.
- GS1 DataMatrix, a small square 2D barcode that can hold the GTIN plus batch, expiry and serial number in GS1's standard format.
- QR code, another 2D symbol that phones read natively. A QR code can hold anything: a plain web address, a coupon, or a GS1 Digital Link that contains your GTIN in a standard, web-friendly form.
That last point is the one people miss. "QR code" describes the shape of the symbol, not what is inside it. A QR code holding https://example.com/summer-promo contains no GTIN at all. A QR code holding a GS1 Digital Link such as https://example.com/01/09501101530003 contains the GTIN in a form that both phones and GS1-capable scanners understand. The difference is explained in what is GS1 Digital Link?, and the three things people mean by "GS1 QR code" are untangled in what is a GS1 QR code? For a practical comparison of the striped barcode and the QR code — scanners, size and damage tolerance — see barcode vs QR code.
Which 2D carriers work at the checkout?
For general retail, GS1 lists exactly three 2D options for checkout scanning: GS1 DataMatrix, a QR code with a GS1 Digital Link, and a Data Matrix with a GS1 Digital Link. These are the codes covered by Sunrise 2027 (GS1 global calls it Ambition 2027), a voluntary retail-industry goal for checkouts to read 2D as well as linear barcodes by the end of 2027. It is not a law. For now, GS1 rules require the linear barcode to stay alongside the 2D code while checkouts upgrade. How the two compare is covered in QR code vs GS1 DataMatrix.
The serial number: one individual unit
A GTIN tells you a bottle is Ambre Nuit 100 ml. It cannot tell you which bottle. For that, you add a serial number. In GS1 terms, the serial is meaningful together with the GTIN: GTIN plus serial identifies one unit, and the same serial under a different GTIN would be a different item.
Serials are usually created by the brand's ERP or serialization system and printed on the packaging line, one per unit. Because each unit is different, serials cannot be part of fixed pack artwork; they must be printed as variable data during production.
Between "type" and "unit" sits the batch or lot number, which is shared by everything made in one production run. Batch is useful for recalls and expiry, while serial is needed when you track, verify or reward individual units. See what is product serialization? for when unit-level identity is worth the effort, and GTIN, batch, serial, SSCC and GLN explained for the full set of identifiers.
Putting it together: one bottle, three layers
Here is how the layers appear on a single 100 ml bottle of Ambre Nuit:
- Identity: GTIN
09501101530003, assigned once by Maison Ardent from its company prefix. - Instance: batch
L2609and serialA7K29Q, printed on the line for this bottle only. - Carriers:
- an EAN-13 barcode on the box, holding the GTIN for today's checkouts;
- a QR code holding a GS1 Digital Link,
https://example.com/01/09501101530003/10/L2609/21/A7K29Q, which carries all three values together.
A modern checkout reading the QR code extracts the GTIN and looks up the price in the retailer's own system, exactly as it would from the EAN-13. A consumer's phone opening the same code goes to a web page about this specific bottle. One identity, two carriers, several uses.
What none of them prove
A GTIN, a barcode, a QR code and a serial number can all be copied. A counterfeiter can photograph a genuine bottle and reprint everything on it. A unique serial does make copying detectable, because a system can notice the same serial being scanned in two cities. But detection depends on server-side rules and monitoring, not on the code itself. We explain this in why a QR code does not automatically prove authenticity.
The one thing to remember
When someone says "we need a barcode", ask which layer they mean. Do you need an identifier (a GTIN from your GS1 licence), a carrier (a symbol printed on the pack), or instance data (a batch or serial number per unit)? Each comes from a different place and is owned by a different team. The GS1 system that ties them together is introduced in What is GS1?
See your GTIN as a GS1 Digital Link QR code