Barcodes for small shops: what they are and how to use them

A barcode is a number printed as stripes so a machine can read it quickly. That is all. It does not contain the product name, the price or the size. When a scanner reads it, it gets a number, and your system looks that number up in your own list to find the product.

That one fact explains most barcode confusion. If a product is not in your list yet, a scan finds nothing. And if two different products in your list share one code, the scan cannot tell them apart. The number is only as useful as the list behind it.

Two retail formats cover almost everything on a grocery or hardware shelf. A UPC (UPC-A) has 12 digits and is common on goods from North America. An EAN (EAN-13) has 13 digits and is common on goods from Europe and much of the rest of the world. A 12-digit UPC can be written as a 13-digit EAN by adding a leading zero, so most scanners and software treat the two as interchangeable.

You will also see shorter codes on small items, and square codes (QR) on some packaging. A standard retail scanner handles the common ones. If you stock a mix of imports, expect to see both lengths side by side on the same shelf.

Whenever a product has a barcode from the maker, use it. You do not have to print anything. The code is already on the pack, every unit of that product carries the same one, and your suppliers' invoices often quote it too.

1. Scan the pack

   Open the product in your list, or create it, and scan the barcode into the barcode field.

2. Check the match

   Make sure the name and price you see are for the same size and brand as the pack you scanned.

3. Never reuse a code

   One code, one product. If you sell a 500 ml and a 1 L of the same drink, each has its own code and its own entry.

4. Test it

   Scan the pack again at the counter. If it finds the right product, you are done.

Doing this for all your products at once is a big job, so start with the top sellers. See ABC analysis for how to find them.

Loose goods, local products, repackaged items and some imports have no usable barcode. You have three sensible options.

• Print your own labels. Give each product a short code you invent, such as a sequence from 1001 upward, and print it as a barcode on a sticker. This is the best option for things you sell often, such as your own repacked sugar bags.
• Skip the barcode and use search or favourites. For a handful of items, a favourites tile at the till is quicker than any sticker.
• Use a shelf label sheet. Put a printed page of barcodes near the till for loose items, and scan from the page.

Whichever you pick, write down the rule. If you invent codes, keep the list somewhere safe so the same number is never given to two products. See naming and organising products for how to keep your list tidy.

There are three common ways to scan, and you can mix them.

A basic handheld scanner costs far less than a till terminal and does the same job. For most small shops the order is: start with the camera, and add one Bluetooth or USB scanner when your queue tells you to. Before you buy one, check that your software works with standard scanners and does not require a particular brand.

Keep in mind that scanning only finds products in your own list. That is why building the list comes first. Read about how barcode scanning works in Shopkeepa.

A six-pack of soda usually has its own barcode, and each can inside it may carry a different one. A case of 24 may have a third. This is where stock counts go wrong, so decide how you will treat each.

A simple rule: track what you sell at the till. If you sell cans singly and as six-packs, make two products and keep them separate. Each has its own barcode, price and count. When you open a six-pack to sell cans, record it as a stock adjustment and count the cans accordingly.

In this example the six-pack saves the customer 50 cents against six singles, which is a choice you make on price, not on the barcode. If you buy by the case and sell only singles, receive the case as 24 singles so the shelf count matches what the customer buys. Do not count in fractions of a pack.

• A scan finds nothing. The product is not in your list yet. Add it, then scan again.
• A scan finds the wrong thing. Two products share a code in your list. Find the duplicate and correct it.
• The code will not read. Clean the label, check the lighting, try holding the scanner a hand's width away. Type the digits by hand as a last resort.
• A new pack, same product. Makers sometimes change the barcode when they redesign the pack. Add the new code to the same product rather than creating a second one, if your system allows more than one code.
• A supplier code that is not a retail code. Case or carton labels often carry a different number from the pack inside. Do not mix them up.

1. Day 1: List your 30 best sellers.
2. Day 2: Scan each one into your product list with its manufacturer barcode.
3. Day 3: Ring up ten test sales by scanning. Fix anything that does not match.
4. Day 4: Decide the rule for loose goods and make labels for them.
5. Day 5: Decide how you treat multipacks and cases.
6. Day 6: Use the scanner for a section stock count. See how to do a stock count.
7. Day 7: Add the next 30 products.

Shopkeepa supports scanning with a phone camera, or a Bluetooth or USB scanner, and recognises the products you have added to your own list. It is in development, so join the early access list if you want to try it.