This wikiHow teaches you how to convert a standard SIM or micro SIM card to a nano SIM. Although SIM cards can vary in size, the part of the card that actually stores information is the same size for all three types of cards. Be aware that cutting your SIM card incorrectly may leave it unused or unrepaired, so proceed at risk.
Steps

Step 1. Gather your supplies
You will need to get the following things to cut the SIM card:
- a pair of straight, sharp scissors.
- a nano SIM card to compare
- a pencil
- a file (or sandpaper)
- a rule

Step 2. Know what to avoid
When cutting a SIM card, you should not cut the metal part of the card, as doing so will render it useless (and irreparable). The best way to make sure you don't accidentally cut the metal is to cut wider than necessary and then use the file or sandpaper to polish the card to the size you need.

Step 3. Take the card out of your old phone
If you haven't removed the SIM card from your old phone yet, remove it before proceeding.

Step 4. Determine the current size of the SIM card
With a ruler, figure out which of the following cards to cut:
- Micro SIM: measures 12mm by 15mm
- Standard SIM: measures 15mm by 25mm

Step 5. Cut off the excess of a standard SIM card
If you're trying to cut a standard SIM card, start by cutting along the line formed by the cutout sections on the left side of the card. This should leave a couple of millimeters of space between the left edge and the metal part of the SIM card.
- The left side of the standard SIM card is the side that does not have an angled cutout in the corner.
- Skip this step if you have a micro SIM card.

Step 6. Place the nano SIM on the other card
You can't properly measure the amount of space to cut without using a nano SIM as a guide. To make sure you do this as correctly as possible, do the following:
- Lay the standard or micro card on a flat surface.
- Make sure the angled corner of the SIM card is in the upper right corner of the card when you look at it.
- Place the nano SIM on the card.
- Make sure the angled corner of the nano SIM card is in the upper right corner of the card when you look at it.
- Make sure that most of the lower left corner of the nano SIM card is aligned with the lower left corner of the SIM card you are cutting.

Step 7. Mark the nano SIM on the card below
With a pencil, draw a line along the edges of the nano SIM card. This will help guide the amount to cut.

Step 8. Cut by what you marked
It is better to err on the side of caution, so don't worry if you cut a little wider than the lines you marked.

Step 9. Try to locate the SIM card on the tray
It probably won't fit, but this will give you an idea of how much more you need to cut the card.
Some Android phones do not have a SIM tray. If this is the case with your phone, try inserting the SIM card into its slot

Step 10. File off any excess plastic
Using a file or sandpaper, remove most of the plastic edge from the bottom and sides of the SIM card.
- Keep most of the plastic intact on top of the SIM until after you've tested the card's fit.
- Keep in mind that a nano SIM card has about a millimeter of plastic around its perimeter, so don't remove all of the plastic.
- Use the nano SIM card you already have as a reference for this step.

Step 11. Try to locate the SIM card in the tray again
If it comes in, it means that you have successfully cut the card to the size of a nano SIM; At this point, you can already test it on your phone by inserting it and turning the phone on.
- If the SIM card still does not fit, you will have to file it a little more.
- Again, if you use an Android phone that doesn't have a SIM tray, try inserting the card into its slot.
Advice
- Consider purchasing a micro SIM cutter from a retailer or online store if you are not comfortable cutting the card yourself. A micro SIM cutter is a device that works similar to a hole punch and can be found on websites such as Amazon, Walmart, and eBay.
- Find out if your mobile operator can cut the SIM at a corporate retail store. In many cases, the mobile operator's corporate retail stores can cut the SIM for free to fit your mobile device.
Warnings
- Cut a micro SIM assuming the risk; Damage to the card during the cutting process cannot be reversed and you will have to purchase a new card if you accidentally cut the metal contacts.
- The warranty from the service provider does not cover damage to the SIM card.