Encoding NFC Tags

Encoding Overview

Encoding is the process of programming data onto an NFC tag. It's similar to storing a file onto a USB stick.

When most NFC tags are manufactured, they contain two basic sections of information - a unique ID (UID) and some data to allow tag readers to identify the type of tag. Any additional data, such as a web address or your own unique ID, needs to be encoded onto the tag.

NFC Tags can be encoded with almost any NFC enabled Android mobile phone. This can work well if you are experimenting or encoding only a few tags. However, if you are encoding hundreds or hundreds of thousands, then you almost certainly want Seritag to handle your encoding. This is how it works.

Note that NFC tags can be provided locked or unlocked. We will cover this at the bottom of this page on Notes on locked/unlocked tags..

Step 1 : Decide what you want encoded

For the vast majority of applications, the data to be encoded is either a URL (web address) or text containing an ID. Seritag can encode other forms of data but we need to speak with you first.

Let's consider encoding a web address, for example There are three ways you might want to encode this.

Single Encoding

This is easy. You simply want to encode the web address exactly the same onto every single NFC tag. If you ordered 1,000 tags, then you would recieve 1,000 tags all encoded with You can order this online by selecting 'Single Encoding' and entering your web address into the box. Remember to add either http:// or https:// (for a secure server link) as that part also gets encoded. The link and link structure is always checked by us before encoding so if something doesn't look right, we'll contact you before we go ahead. For larger orders, we may also send you a sample to double check. Locked or unlocked tags ?

Variable Encoding

So now let's assume you want to encode something different on each tag or perhaps in small groups. This is called variable encoding because each tag doesn't contain the same data. In this instance you need to provide a spreadsheet with your order telling us what you want. For example, you might want each tag encoded with different data. For example, you might want the first tag encoded with and then the next with and so on. Alternatively, you might want 120 tags encoded with then 143 tags with Here are a few examples.

Example 1. Variable web address encoding. No ID print. Single batch. Example 2. Variable encoding in grouped quantities. No ID print. Single batch. Example 3. Variable encoding in groups. No ID print. Split/cut into separate named batches.


Normally, NFC tags are supplied on a single reel or, in lower quantities, small strips. Batching is where the tags are sent to you in separate packs. This may be in small bags for a few tags or it might be separate reels for larger orders. This might be because you are using the tags for different things or sending them to different departments or printers. In this case, you need to upload your spreadsheet with the batches listed as in the example above. When ordering online, you also need to specify how many batches you are ordering. You can find more information on how tags are delivered.

Step 2 : Place your order

Once you have your spreadsheet or encoding URL ready, then you can just order online. If you are not sure or have a very complex order, then you can always just email us the spreadsheet and we will guide you through.

Step 3 : Encoding and delivery

We check over your order very carefully before starting to encode. If we think there may be a problem then we will contact you before we begin. We are very experienced with encoding so we know what to look for. For larger orders, we may contact you and then send a sample tag before we go ahead. We will always contact you first.

Important note on privacy : Seritag understand that sometimes the data sent to us will be for projects not live yet. Unlike some NFC suppliers, Seritag encode all tags in house using our own equipment. We do not pay licence fees or need to upload any data to anyone else. Your data will remain with us at all times and, should you choose, can be deleted from our servers after encoding is complete. Additionally, we can usually return non-disclosure agreements, if required, quickly and without delay.

Confused ? Contact us. We are here to help.

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