Editing SIM lock (section)

==== Unlock code generators ====
There are online services that will provide an IMEI unlocking service for [[List of Nokia products|DCT4 and DCT3 Nokia]] mobile phones.{{citation needed|date=May 2013<!-- do not use promotional web sites as references - see [[Wikipedia:Reliable Sources]] and [[Wikipedia:Spam]] -->}} This method of unlock requires the user to know which carrier the mobile phone is locked to, and also needs to provide an IMEI. Generally, older model Nokia unlock codes are free and instantly retrievable by these services. The unlock codes retrieved must be entered into the mobile phone using the keypad.

For [[List of Nokia products|DCT4 and DCT3 Nokia]], unlock codes consist of a "#" key, followed by "pw+", 10 (DCT3) or 15 (DCT4) digits, "+", and another number ranging from 1-7, and finally ends with a "#". Depending on the carrier which the phone is locked to, only some codes will work with the mobile phone. Most phones respond to the unlock codes ending in +1# or +7#, however some phones are configured to allow only one of the seven codes to work.  The following is an example of a DCT4/DCT3 unlock code:
<pre>
# pw+931882753035021+7#
</pre>

DCT4 and DCT3 Nokia will only allow a maximum of five unlock attempts using the unlock code method. After five incorrect codes have been inputted, the phone will not allow the user to try any more codes (even if it is correct) and will require the owner to try other unlock methods.