How to Flash a Phone

If you want to use your old cell phone with a new carrier, you will need to know how to flash a phone. Flashing is also referred to as reprogramming. You can also take your phone to various authorized cell phone dealers to get it flashed for you, but you can learn how to flash your phone yourself.

Working with the Right Equipment

Make sure you are trying to flash a CDMA phone.

CDMA stands for Code Division Multiple Access. If you are uncertain whether your phone is CDMA or not, remove the battery and look for a removable subscriber identity module (SIM) card under the battery. If there isn’t a SIM card, you indeed have a CDMA phone that can be flashed.

  • GSM (Global System for Mobile Communications) phones can’t be flashed (like AT&T and T-Mobile). Metro, Sprint, Cricket, Boost, Verizon and many others are CDMA and thus can be flashed because they’re not controlled by the SIM card. (Since Metro has merged with T-Mobile they have introduced phones with SIM cards so flashing may vary from phone to phone.)
  • Your phone must also have a clean ESN (electronic serial number) — that is, it must never have been reported lost or stolen.

Get out your USB cord.

The same one you use to connect to your computer to download music and whatnot will be used with this process.

Search for compatible flashing software.

There are several easy-to-use flashing programs that make flashing easy, and some are even free to download. Make sure the one you choose will work with your particular phone before attempting to flash.

  • Examples include and Search around before you risk damaging your phone with an inadequate or incompatible program.

Know what you want to flash your phone to.

You are changing your phone from your current carrier to something else. The only stipulation is that it also must be a CDMA network. Cricket, Page Plus, and Metro PCS are three popular options.

  • You can check the reception in your area for various carriers at Might as well before you make the leap! Certain programs are affiliated with larger networks, like Page Plus is with Verizon.You can get an hour’s trial of Page Plus from their website.
  • You can get an hour’s trial of Page Plus from their website.

Proceeding with the Flashing Process

Download the flashing program of your choice onto your computer, and unzip the files.

Carefully read the instructions and follow them carefully. After reading the instructions, you will be able to flash your phone within 15 or 20 minutes.

  • Because each phone’s set up is a bit different, it’s impossible to outline step-by-step guidelines here. However, there are generally a few things you need to know that we’ll try to cover.

Check for drivers.

If you’re unsure whether your phone is up-to-date or not, it’s fairly simple to get the latest online. As long as you know your phone’s model number or name, you’ll be good to go. If you don’t, you can find that online, too.

  • Make sure you have all the drivers you need before you flash! Otherwise the process may not work. Visit your phone company’s website (e.g., Samsung) to do so.

Know the basics.

The software will ask you what your original carrier was, what you’re flashing to, and your phone’s make and model. It will also prompt you to choose between a “half flash” and a “full flash.” A “half flash” is just talk and text, nothing else.

Know your MEID and ESN.

If you get into the program you’re using to flash, you can “read” the phone, which will then give you all the information you need to continue with the process. Or you can get into it beforehand. The MEID and ESN can be found underneath your phone’s battery.

  • The MEID will be 18 digits (starting with 2) if it’s MEID Dec or 15 numbers and letters if its MEID Hex.
  • The ESN will be 8 numbers long and possibly labeled PESN.

Detect your phone.

Your software should have an option to detect your phone, allowing it to be read. If you do this, you don’t have to worry about determining the COM port yourself — it should be able to figure that out for you.

  • If it is asking you your unlock code, for Verizon phones this is always six zeroes. The lesser common, but still possible, options are six ones or six threes.
  • Certain phones may require you to mess with the PRL. In the US, the code is *228 (for Verizon/MetroPCS/US Cellular) and ##873283# (“update,” in case you didn’t notice) for Sprint. In Canada, it’s *22803 for Telus Mobility.
  • If for some reason the COM Port is giving you guff, you can manually find what port it is in through your Device Manager.

Choose “write.”

Most software will have you select “write” and then ask you to confirm. Once you select “yes,” the phone will proceed to get flashed and automatically reboot when successful. That’s it! You’re done. Almost too easy, huh?

Recognizing the Risks

Know that “bricking” your phone is an option.

This is the term used for a “sudden death” of your phone. It becomes virtually useless…unless you want to use it as a brick.

  • This risk still exists even when done by a professional. The odds are lower than if you ask your geeky roommate to do it, sure, but it’s still there.

Understand that any warranty you had will be voided.

Makes logical sense — you abandon your carrier, they abandon you. However, if you go to a retailer and they do it for you (which is an option), your warranty may stay intact (depending on your circumstances, of course).

Make sure your flashed-to carrier accepts foreign ESNs.

If you’re flashing to Boost or Cricket, you shouldn’t have a problem. But flashing to a behemoth like Verizon could pose some issues — they approve of fewer “at-home” remedies such as this.

Know that you’re still using the same technology.

When you’re working with a CDMA phone, whether it’s flashed or not, you’ll still be relying on CDMA technology. If you live in the US and travel a lot, most phones in other countries are of the GSM variety (i.e., have a sim card). The main benefits of flashing your phone are in saving money and supporting the littler guys.

  • All carriers within the US with the exception of AT&T and T-Mobile use CDMA technology. Their numbers (ESN) are hard-wired and cannot be changed, unlike their GSM peers.

Flashing your phone to Straight Talk is illegal.

You need to replicate your phone’s ESN to do this, thus cloning it. Having two phones with the same number is obviously fishy and is a crime that could lead to some hefty fines or more. If you are contemplating Straight Talk, see their website and talk to a professional beforehand.


  • Flashing can save you money because you eliminate the need to purchase a new phone once you switch over to your new carrier. You may also be able to take advantage of a cheaper plan offered by other carriers when you have the ability to flash your phone.


  • CDMA phones can used only with CDMA carriers such as Metro, Sprint, Cricket, Boost, and Verizon.
  • Flashing a phone yourself will void its manufacturer warranty. If you take the phone to an authorized dealer or service shop, it can be flashed without voiding the warranty.
  • Only CDMA phones can be flashed. GSM (Global System for Mobile Communications) phones that contain a SIM card, used by carriers such as AT&T and T-Mobile, cannot be flashed. If you have a GSM phone, you are locked into using your phone with whatever carrier you originally signed up with.
  • There are always risks involved when flashing a phone. Data could be permanently erased or the phone could stop working completely. Flash at your own risk, and be sure that you follow the software directions if you do decide to attempt flashing yourself.
  • A CDMA cell phone can be used on a compatible CDMA network only if your new carrier is willing to activate the phone on its network. Budget carriers such as Cricket or Boost will typically allow flashing, while larger mainstream carriers like Sprint or Verizon will not. It is a good idea to call the new carrier and confirm that they accept foreign electronic serial numbers (ESNs) before attempting to flash.

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