1. Where can I find my list of bar code numbers?
2. I am not sure how to use the online Numberbank facility?
3. What is the best way to keep a record of my numbers?
4. Which colours can I use for my bar code?
5. I have been asked to label my pallet with a UCC/EAN-128 bar code. Which number do I use?
6. Will my bar code work outside the UK?
7. I have been asked for an SSCC. What is it and how do I create it?
8. What is a Global Location Number (GLN)?
9. Why do I need to provide a GLN to my trading partners and how do I communicate it?
10. How small can I print my EAN/UPC bar code?
11. How do I create a bar code for my case?
12. How do I log in to the members' on-line area?
13. I have been asked to put a label on an outer case using an EAN/UCC 14 digit number. What number do I use?
14. I have an ISBN number for a book. How do I change it into a bar code number for it?
15. I have been told my bar code will not scan, why is this?
16. My product is being rejected. Can I send it to GS1 UK for testing?
17. I have been told my UPC bar code cannot be accepted, what should I do?
18. The person who created bar codes for our products has left and we don't know how to do this. Help! What do we do next?

If you would like to add a question to this list please email it to info@gs1uk.org.

1. Where can I find my list of bar code numbers?
The Numberbank facility on the GS1 UK website provides you with a complete list of your bar code numbers, including their correct check digits. When you join GS1 UK, a complete list of your company's available numbers is recorded on your Numberbank. Each Numberbank is secure and can only be accessed by your company via the members' only area of the website. Click here to login to to the members' area.

2. I am not sure how to use the online Numberbank facility?
You can currently store two different types of numbers online. The first type is the bar code numbers for your products which are properly called global trade item numbers or GTINs. The second type is global location numbers (GLNs) that are used to identify companies and locations and these are chiefly used for electronic communications. It is important that you keep an accurate record of the numbers you have assigned to avoid any duplication of numbers and confusion with your trading partners. For more information on how you can make use of our password protected members' area, please call the GS1 UK Service Team on 0808 178 8799 or email info@gs1uk.org.

3. What is the best way to keep a record of my numbers?
Ideally you should maintain your own database record of all your product lines and the GTINs used to identify them, but you can also use our Numberbank facility to do this. The Numberbank provides a listing of all the 13-digit numbers available for you to use, and you must make sure you choose the GTIN list for all your products, and the GLN list for all your company locations. The Numberbank facility is found in your password protected members' area. For more information or to find out your login and password details please contact the GS1 UK Service Team on 0808 178 8799 or email info@gs1uk.org.

4. Which colours can I use for my bar code?
Bar codes should be printed so that the darker bars appear against a paler background. Always use a pure colour rather than one created using the conventional four colour process. Black bars on white background are a widely used combination, but other colours may be used, provided the bars have a high blue, black or green content and are printed on a background that is white, yellow, orange or red. Remember, scanners use red light to detect the difference between the bars and spaces, so the bar colour must appear black under red light and your background should appear red. More information can be found in GS1 UK's publication "Bar coding - getting it right", which was distributed as part of your membership pack. If you require a new copy of this document please email the Service Team at info@gs1uk.org.

5. I have been asked to label my pallet with a UCC/EAN-128 bar code. Which number do I use?
Every pallet must be identified with a unique 18-digit serial number called a serial shipping container code (SSCC), and extra information about the pallet's contents can also be shown using UCC/EAN-128 bar codes. To find out how you can create SSCCs from your company prefix number, and provide information such as best before dates and batch numbers, see Section 7 of "Bar coding - getting it right" or on the GS1 UK website go to Bar code numbers, and then Symbologies.

6. Will my bar code work outside the UK?
The simple answer to this is question is 'YES'. The GS1 System is a global standard and therefore your EAN-13 bar code can be used around the world.

7. I have been asked for an SSCC. What is it and how do I create it?
An SSCC is a serial shipping container code, an 18-digit serial number that identifies each pallet uniquely so that it can be tracked during transit. The SSCC must be shown in an UCC/EAN-128 bar code using the standard GS1 pallet label (see pages 19 and 20 of Bar coding - getting it right ). The SSCC is created by using your company prefix number and adding a serial number to identify each pallet. The last digit is the check digit.

8. What is a Global Location Number (GLN)?
A GLN is used to identify companies and other physical, or legal locations, such as head offices, goods in/out, manufacturing site. GLNs are formed in exactly the same way as 13-digit GTINs and are held in separate sections of the Numberbank facility of the GS1 UK website. If trading partners request your company's GLN, you will need to allocate one GLN to your company and communicate this number to your trading partners. A company must only identify locations for which they are responsible.

9. Why do I need to provide a GLN to my trading partners and how do I communicate it?
GLNs make it possible to automate electronic communications and they are used to identify all the companies and locations involved in the trading process. Your GLN and associated details will be communicated to your trading partner before you start trading, often using the Party Information message in EANCOM or XML-based business messages. GLNs can also be used in UCC/EAN-128 bar code on pallet labels to give instructions about the delivery destination.

10. How small can I print my EAN/UPC bar code?
We always recommend that you print your bar code at 100% size. Only print a smaller symbol if you have no other choice. You may reduce the symbol down to 80% of the nominal size, but always remember that the smaller the symbol the more accurate the printing process has to be. If you are producing bar coded labels on demand you can produce symbols at a magnification of 76%. Remember to always keep the height of the bars as tall as possible. More information can be found in Section 12 and Appendix 1 of 'Bar coding getting it right' and in Section 5 of the General GS1 Specifications (formerly EAN.UCC Specifications).

11. How do I create a bar code for my case?
The simplest way to do this is to create a new 13-digit number as you would for any other product. If you are encoding this number in an ITF-14 or UCC/EAN-128 bar code you will need to prefix this new number with a '0'. Leading zeros have to be used with ITF-14 and EAN-128 bar codes because these symbols cannot represent an odd number of digits. More information can be found in Section 7 of 'Bar coding getting it right'.

12. How do I log in to the members' on-line area?
When you joined as an GS1 UK member, we issued a joining letter with your registration pack. This letter contains your company prefix, your company log in and your company password. Armed with this information you can now proceed to our website home page www.gs1uk.org.
On the home page click on a red login stripe on the right hand side of the page and go to the member's on-line area. You will then see two links on the page, 'company details' and 'individual users'. Click on the 'company details' link and enter your company login and password, referred to in your joining letter. After you have entered your details then click on the 'sign on' link, you will then be taken in to Your Company Details page.

13. I have been asked to put a label on an outer case using an EAN/UCC 14 digit number. What number do I use?
This bar code is a single number code like an EAN 13. The numbers are created by adding an indicator as a prefix to an EAN/UCC 13 number for a product, and then recalculating the check digit. The indicator can take any value from one to eight and simply creates a different item number for a different packaging configuration. To find out more about how to create an EAN/UCC 14 digit bar code number look in section Appendix 2 of 'Bar coding - getting it right'.

14. I have an ISBN number for a book. How do I change it into a bar code number for it?
The 13-digit number you need is created by prefixing the first nine digits of the ISBN with 978 and then recalculating the check digit.

15. I have been told my bar code will not scan, why is this?
There are various factors that affect the scanning of a bar code. Poor print quality is usually the main reason, but poor positioning and incorrect bar code size will also have an adverse effect on scanning. It is important to check the symbol quality, size and positioning before supplying your goods. This is called 'verification' and is best done by simulating the finished product or packaging. The verification process looks at various different aspects of the bar code before giving you a pass or fail grade. Bar code dimensions can be found in Appendix 1 of "Bar Coding: Getting It Right". Section 9 of the General EAN-UCC Specifications explains the verification process, whilst the correct position is covered by Section 6. Both guides are available from the Service Team on 0808 178 8799 or email info@gs1uk.org.

16. My product is being rejected. Can I send it to GS1 UK for testing?
GS1 UK does not offer a testing service. However if you are experiencing a problem we may be able to help. We recommend that you use a bar code verifier to check bar code quality, or contact one of the solution providers who provide verification testing as a service. Visit the Solution Provider Finder section of the GS1 UK website for further details.

17. I have been told my UPC bar code cannot be accepted, what should I do?
The most common errors with the UPC bar codes happen during data entry. Your customers are probably used to inputting 13-digit codes and when faced with a 12-digit number they do not always realise they need to add a leading zero as a filler character. Once they understand this they will be able to add your number to their system. Remember the Service Team is here to provide you with support for implementing GS1 standards that include bar coding and numbering, global data synchronisation, electronic messaging implementation and EPCglobal. If you require any further information on any aspect of the GS1 System then you can view the General GS1 Specifications (formerly EAN-UCC Specifications) on our website, call the Service Team on 0808 178 8799 or send us an e-mail at info@gs1uk.org.

18. The person who created bar codes for our products has left and we don't know how to do this. Help! What do we do next?
Although GS1 UK does not keep records of the bar code numbers you have created, we can still help. Take the following steps:

Check your internal records on either a database or spreadsheet; see which numbers you have assigned

Check all your existing stock for products that have bar codes already on them

Ensure you keep a record of the numbers you assign to your products. If no records have been kept, you need to apply for a new prefix number, so you can bar code new products. This will also ensure you do not duplicate numbers you have used already. It is extremely important you do not duplicate any numbers, as this will cause serious problems when supplying to your customers. Once you have a record of your numbers assigned to your products, contact our Service Team to find out your company prefix number

When you have your company prefix number, you are ready to start creating unique 13 digit global trade item numbers (GTINs) for your new products

When you have your numbers, you will also need to make sure you have a printer that can produce the bar code images for your products. The bar code symbol must be produced in the EAN-13 format. If you are not able to produce the bar code images yourself, you can contact some of our solution provider member companies who can help with creating bar codes, which incorporate your unique numbers. You can get a full list of these companies by checking out the Solution Provider Finder