How do you choose NFC tags and cards?
Start from the object and the surface, not the chip. Antenna size decides read distance, the substrate decides survival, and the tag type decides which phones respond. The chip reference determines memory and features, which matter far less often than product listings suggest.
The order to decide in
Most people start with the chip because that is what listings advertise. It is close to the least important variable, and starting there produces tags that are technically correct and physically wrong.
The order that works runs the other way. What object is the tag going on, and what is that object made of. How big can the tag be. Who is going to read it, with what. Only then, what does the content need.
A sticker on a metal machine housing fails whatever chip is inside it. A tag too small for the required distance fails whatever chip is inside it. Those decisions come first because they are the ones that cannot be fixed later.
Four questions before you buy
| Question | What it decides | Cost of getting it wrong |
|---|---|---|
| What surface? | Whether you need an on metal tag | Total failure after application |
| How much room? | Antenna size, and therefore read distance | Unreliable taps, blamed on phones |
| Read by whom? | Tag type, and therefore compatibility | Works for some visitors and not others |
| Holding what? | Memory, and any features needed | Content does not fit, discovered late |
Only the last of those is answered by a chip reference. The first three are answered by the physical product.
Where the chip does matter
Memory, when the content is larger than a short web address. A contact card or Wi-Fi credentials need noticeably more room than a link.
Features, when you need password protection, a read counter, or the ability to mirror the tag identifier into the content. None of these can be added later, so they are a purchase decision rather than a configuration decision.
And compliance, in the sense that a chip conforming to an NFC Forum tag type is one that phones will read without special software. That is the single most important property and it is a property of the chip.
What listings do not tell you
Antenna dimensions, almost never, even though that is what sets read distance.
The NFC Forum tag type, frequently omitted in favour of the phrase "NFC compatible", which is unregulated and means nothing.
Usable free space, as opposed to total memory, which is always the larger and less useful number.
The two questions that test a supplier
Ask for the chip reference and the NFC Forum tag type. Both, not one. A supplier who can answer neither does not know what they are selling, which matters far more for a thousand printed cards than for a handful of stickers.
All guides in this section
- Choosing a chip
- Memory and capacity
- Form factors and materials
- Antennas and read distance
- Special purpose tags
- Buying and quality
Choosing a chip
- Which NFC chip should you choose, and on what criteria?
- Which chips work with both Android and iPhone?
- NTAG or MIFARE Ultralight: does the difference matter to you?
- When do you actually need more than the cheapest chip?
- Does the chip itself change the read distance?
- What does write endurance mean in practice?
- Do you need a chip with password protection?
- Which chip suits a digital business card?
- Which chip suits a tag that many people will tap?
- What changes if a chip is not NFC Forum compliant?
Memory and capacity
- How much can you actually store on an NFC tag?
- Why is usable memory smaller than the packaging says?
- How long a URL fits on the smallest common tag?
- Do you ever need a high capacity tag?
- Does more memory mean a slower read?
- Store on the tag, or store on a server?
- How many contacts fit on one tag?
- Can you put an image on an NFC tag?
- What happens when you fill a tag completely?
Form factors and materials
- Sticker, card, keyfob or disc: which form factor?
- What is an NFC tag physically made of?
- Which adhesive holds on which surface?
- PVC, PET or paper: which substrate lasts?
- Are wooden and bamboo NFC cards a good idea?
- Are metal NFC cards usable?
- Can an NFC tag be printed on?
- Can an NFC tag be laminated?
- Can you cut an NFC tag to size?
- What tag size do you need for a given read distance?
- Are NFC wristbands and rings practical?
Antennas and read distance
- How does antenna shape affect performance?
- Why does the same tag read differently on two phones?
- What read distance can you realistically promise a client?
- Does stacking two tags work?
- How close can two tags be placed?
- Does a tag inside a wallet still read?
- What happens when a tag is bent?
- Does tag orientation matter?
- Why do bigger tags not always read better?
Special purpose tags
- What makes an on metal tag different?
- Do you need a waterproof tag, and what does the rating cover?
- Which tags survive industrial temperatures?
- Are laundry tags worth it?
- What is a tamper evident NFC tag?
- What are NFC tags with a built in sensor?
- What is a dual interface card?
- Are combined NFC and RFID tags useful?
- What is an inlay, and when do you buy one?
- Are anti metal spacers a substitute for on metal tags?
- Which tag suits outdoor use?
Buying and quality
- How do you tell a good tag from a bad one before buying?
- Why do cheap tags fail more often?
- What should a tag supplier be able to tell you?
- How do you check which chip you actually received?
- What quantity should you order for a first deployment?
- Do NFC tags have a shelf life?
- How should tags be stored before use?
- What is an acceptable failure rate in a batch?
- Should you buy pre encoded tags?
- Which certifications matter for NFC tags?
Frequently asked questions
Does a more expensive tag read better?
Not because of its price. Read distance follows antenna size, so a large cheap tag beats a small expensive one. Price usually buys features or durability rather than range.
Can I change the chip later if I chose wrong?
No. The chip determines memory, features and tag type, and none of them can be altered after manufacture. Choosing wrong means buying again.
Is NTAG always the right answer?
It is a common and safe family for consumer use, and the family name matters less than the tag type and the memory. Ask for those rather than for a brand.
What if the supplier only says NFC compatible?
Treat it as no information at all. The phrase is unregulated and appears on products that no phone will read, so push for the tag type before ordering in quantity.