UPC (Unique porting Code) is Mandatory for MNP Process

In across the country, the service of Mobile Number Portability (MNP) has started from 20th Jan 2011. If you want get benefit from this great service, you must have to get firstly the Unique Porting Code (UPC).  To get this unique number, just send one simple text message from your mobile writing PORT (Your Cell Number) at 1900. When you send SMS to that number, you will immediately receive your UPC from 1901 number.
Basically, UPC (Unique Porting Code) consists of eight characters wherein first two characters specify the name and service area code of the service provider. For e.g. if the first two characters of the code is RD then it specifies a Reliance (R), Delhi (D) number and besides, the remaining six characters will be 1 to 9, A-N & P-Z only and small letters. Moreover, the alphabet ‘O’ will never be permitted in the Unique Porting Code.
There is the list of Operator Service codes as will be given in the first alphabet in UPC number:

List of Codes of Service providers
Bharti Airtel	A
BSNL	B
Datacom Solutions	C
Aircel	D
Reliance Telecom	E
HFCL Infotel	H
Idea Cellular	I
Loop Mobile	L
MTNL	M
Spice Communications	P
Reliance Communications	R
S Tel	S
TATA	T
Uninor	U
Vodafone	V
Etisalat DB Telecom (Cheers Mobile)	W
MTS	Y

Here is again list of Operator Service codes as the second alphabet in UPC:

List of Service Codes for Service Area
Andhra Pradesh	A
Bihar	B
Delhi	D
UP-East	E
Gujarat	G
Haryana	H
Himachal Pradesh	I
Jammu & Kashmir	J
Kolkata	K
Kerala	L
Mumbai	M
North East	N
Orissa	O
Punjab	P
Rajasthan	R
Assam	S
Tamil Nadu including Chennai	T
West Bengal	V
UP-West	W
Karnataka	X
Madhya Pradesh	Y
Maharashtra	Z

Please remember, the Unique Porting Code will be valid for 15 days period only from the date of request for all services areas apart from Assam, Jammu & Kashmir and North East licensed areas. In these areas, the Unique Porting Code validity will allocate to a subscriber for a period of 30 days from the date of request, the sms. Please note one thing that the word ‘PORT’ followed by a space followed by the ten digit mobile number which is to be ported should be case insensitive. For instance, you can’t write port for Port in the message. Furthermore, if the Subscriber’s Caller Line Identification does not match with the ten digit mobile number, no Unique Porting Code will be allotted to the customer. However, he will get a message on the mobile that the Caller Line Identification (CLI) does not match with his cell number.
See more: http://www.connectindia.in/