Unlocking Your Nokia Phone
Schuyler Erle
RSS 1.0 feed for Schuyler Erle. Atom feed for Schuyler Erle.
Nov. 13, 2003 03:27 PM

Print. Print
Email. Email weblog link
Discuss. Discuss
Trackbacks. Trackbacks
Blog this. Blog this

A couple weeks ago, Tim O'Reilly forwarded a posting about mobile
phone interoperability in Europe from the Interesting People mailing
list to ORA's editorial discussion list. It seems that travelling
abroad with a tri-band GSM phone isn't enough, according to UCSD
professor Sid Karin:

... I can't resist relating my own experience with Vodaphone last
month in Europe. I bought a Vodaphone pay as you go phone in London
and ran out of minutes in Switzerland. As it turns out there doesn't
appear to be anyplace in Switzerland that you can go to to to top off
a Vodaphone phone. I went to an Orange store to see if they could
help. They tried, but no luck. It seems that Vodaphone modifies the
Nokia phones that they sell so that competitor's SIM cards won't work.
So much for interoperability and standards.

Well, this was a familiar story. I recently visited the UK, thinking I
would obtain a local network SIM for my Nokia 3650 - which *is* a
tri-band phone, after all - so that I could make calls in country
without paying AT&T's exorbitant international roaming *and* long
distance fees while there.

Needless to say, the phone immediately rejected the European SIM. Then
I proceeded to visit a sequence of cell phone service/repair shops in
London, each of which assured me that they could programmatically
unlock my phone, before returning within ten or twenty minutes to
confess that they could not om fact do it. Most independent mobile
service locations in the UK have, apparently, a Windows application,
that allows them to somehow modify the firmware on phones like mine --
but they need some kind of access code to do it, and the repair shops
in the UK just didn't have the necessary code. "Which provider do you
use in the US?" I was asked by one. "AT&T? That's not on my list."

So much for getting a local SIM abroad. Rumor had it that AT&T would
unlock my phone over the air for a fee, so, after I got back to the
States, I called their customer service to inquire about it. "Oh no,
that phone can't be unlocked, it's been locked by the manufacturer," I
was told. Uh huh, right. A call to a local retail location yielded the
response, "Yes, the phone can be unlocked, but we aren't trained to do
it, and we don't recommend it. You might damage your phone."

Well, I've never been one to let a little warning like that stop me.
After all, I paid for the phone, and I want it s full capability.
Granted, AT&T gave me a hefty rebate on the phone, but as far as I can
tell I'm under no obligation to keep the phone that I already paid for
in any particularly half-crippled state.

Enter O'Reilly editor Brian Jepson, who remarked in response to Tim's
forward that:

If you want to do it yourself, recent Nokia phones are pretty easy
to unlock (download some freeware to generate a code); Sony Ericsson
phones need a special cable (usually best to send it out to someone to
have it done). IANAL, but from what I've read, it's not illegal to
unlock, but it is sort of cheating. If you want to avoid the problem,
just buy an unlocked phone (but you'll pay a lot more).

Unable to resist a challenge (and not wanting to repeat this month's
phone bill the next time I go abroad), I called AT&T again to inquire
of their customer service department - hypothetically, of course - if
there was anything in my service contract that would leave me liable
for termination of service or legal action if I did unlock my phone. I
was told, first, that nothing in my service contract with them
prevents me from unlocking my phone; second, that AT&T has no way of
knowing if I have unlocked my phone; and, third, that unlocking my
vendor-locked phone was illegal. When I pressed for details on the
illegality of SIM unlocking, I was told they couldn't provide me with
any further information on that subject. And, of course, I've never
been misled by an AT&T representative, heavens no.

So I decided to go ahead. This information is provided for educational
purposes only, and you should understand that acting on this
information may irreparably damage your SIM and/or your phone. As far
as legalities go, check the contract from your service provider, as
some contracts may prohibit this activity. O'Reilly & Associates, Inc.
disclaims any liability for any consequences of using this

I started by googling for nokia unlock software, and, lo, and behold,
I found unlockme.co.uk, which has a substantial section on unlocking
Nokia phones, including freeware downloads and a walk-through
tutorial. I couldn't get the Win32 unlock code calculator from
unlockme.co.uk to run under wine on Linux, but at Brian's
recommendation, I also visited unlocksmith.com, which offers a
self-extracting, freeware Nokia DCT4 unlocking suite. (Don't ask me
what the difference between DCT3 and DCT4 is - the aforementioned
sites will tell you which one applies to your phone.) When I installed
this package in wine, I found a command-line tool called DCT4NCK.EXE
that wine executed with no trouble at all:

DCT4NCK by jozso v0.0a
Usage: dct4nck locktype imei provider [boxserial]

The locktype, according to unlockme.co.uk, is usually 2, unless you're
on a 3650 or 7650, in which case it's 5. The IMEI is the hardware
serial number of your phone, which you can read off the inside label
underneath the battery, or retrieve from the phone itself by dialing
*#06#. Finally, you'll need the provider code, which is a 5-digit
number you can pull from this network provider code list. Unlock code
calculators give you seven different codes, at least one of which
should unlock the phone when entered with the SIM removed, but you
only get five tries, before the phone locks you out. So, you really
want to double-check your work before entering would-be unlock codes
into the phone.

Undaunted, I ran DCT4NCK using the appropriate locktype, IMEI, and
provider code for my phone, and got back seven 22-digit codes.
Following the recommendation of the unlockme.co.uk tutorial, I took
the SIM out of my phone, turned it on, and entered the seventh and
final code listed, hitting '*' consecutive times to get the 'p' and
the 'w', but I omitted one of the digits, and got an error message
from the phone. So I tried again, careful to enter the whole code,
with the same result. Then I noticed that, a little further down, the
network provider list shows special provider IDs for Nokia 3650s with
particular IMEIs -- which included mine! I generated a new set of
unlock codes, and punched the last one into the phone. Same error.

Well, now I was starting to sweat a little. I'd gotten three
consecutive errors, and I only had two tries left. So I went over the
tutorial one more time, and found the following footnote: "For 3650
AT&T USA, always use code 1 out of the 7 generated!" Crossing my
fingers, I tried the first code of the seven I'd generated instead,
and voila -- Success! A message popped up on the phone indicating that
it had been unlocked. I put the SIM back in the phone, powered it up,
and I was back in business, with no apparently harmful side effects.

So don't believe the hype if your network provider tells you that your
Nokia phone can't be unlocked, or if a service location tells you that
you need to pay someone for the privilege. Although your mileage may
vary and you naturally do so at your own risk, with a little time and
a little patience, you too can unlock your own GSM phone, and use it
with a SIM from the service provider of your choosing. Power to the

NOTE (2005/04/30): Please don't email me or post your IMEI here. I'm
not an expert on this subject, and all the information I can offer on
the subject has been given in this weblog entry. You also might try
this site as well. My humblest apologies for any inconvenience.

Schuyler Erle had nothing to do with the Tunguska explosion of 1908.
No, really.


"Until last October, Christ had a very limited involvement in my life. I believed in God; I just never had to prove I believed. Belief is an absence of proof."
-- Boston Red Sox pitcher Curt Schilling

See More: Unlocking Your Nokia Phone