Unlocking your Vodafone phone to use with another carrier

This post is mostly relevant to Australians, but the instructions might also work in the UK, or other countries.

I recently had enough of Vodafone Australia's terrible call quality and slow data network. I am often out of the city centre, and the quality of service is such that it my phone was often unusable. I couldn't even make a call from my home office!

I moved over to Telstra, and found that my phone was locked to Vodafone, even though I remember the sales guy saying it wasn't :) If you Google something like 'unlock HTC trophy' you'll find a bunch of sites offering to give you the unlock code for $35 or more. Luckily Vodafone Australia provides this for free for some handsets. So even though we can't use Vodafone to make a decent phone call, kudos for providing the unlock codes. I know some carriers charge for this.

So the unlock issue is easy to fix, and I thought I'd put the instructions up so others can benefit.
By the way, this phone is an HTC Trophy, but this should work on anything Vodafone sell.

1. On your phone's dialer, type *#06#
2. Write down the number displayed - you will need the first 15 digits. This is your IMEI number.
3. Get a Telstra SIM card and activate it while porting your number
4. Turn off your phone
5. Remove your Vodafone SIM and insert the new SIM.
6. Turn on your phone
7. You will be greeted with a message like: "The SIM card can only be used on specific networks. Contact your customer service centre for the unlock code"
8. Go to https://unlock.vodafone.com.au/voila/handsetunlock/self-service.html?method=selectService and enter the IMEI number and the Captcha
9. An Unlock code will be generated and displayed at the top of the following page
10. Enter this number into the phone and press Enter.
11. Your phone should be ready to use!
12. In some cases the new SIM may also be locked. If this is the case you need the PIN and PUK code from your new carrier's Customer Service dept.