Version /08/2008 The AQ calculation and validation process Compiled and delivered from the xoserve AQ Team for Review Group 209 Susan Prosser & Steve Nunnington.

Version /08/2008 System Calc process G0 to 3. G0 to 11. G0 to 5. G0 to 6.

Version /08/2008 Warnings Report Appendix 1 This is an example of how M Numbers appear within the Warnings Report as part of the AQ Review. Not all Warnings listed within this example

Version /08/2008 Warning Report Reasons  Reason Code and Message Text  MPQ Meter Point is owned by xoserve. AQ not calculated  MPQ Meter Point is not a part of Live Confirmation. AQ not calculated  MPQ AQ not calculated due to the application of backstop date  RCN Reconnection does not exist  MPQ Reconnection Effective date is in the relevant metered period. AQ not calculated  MPQ Meter Point not DM for whole of DM AQ Calculation Period. AQ not Calculated  GNT Gas Nomination Type does not exist  MRF Meter Reading Frequency does not exist  MPQ Calculated annual quantity is negative  MRR Meter read request does not exist  CPN Consumption starts before earliest possible start meter read date  CPN Consumption overlap. AQ not calculated  MRE AQ not calculated due to the absence of reads since the previous AQ calculation  MRE AQ not calculated due to the absence of reads since competition effective date  CPN Consumptions for Meter Point are not contiguous  CPN Negative consumption during metered period. AQ not calculated  CPN Consumption start read more than three years before Target Opening Date or less than six months before Target End date  LCV LDZ Calorific Value does not Exist  CPN Insufficient Consumption Data to Calculate AQ (New MPRN)  CPN Consumption gap. AQ not calculated  CPN Consumption Start Date not equal to start Meter Reading date  SPO Supply Point History not contiguous over whole of relevant metered period  MPC Meter Point Configuration not found G0 to 2.

Version /08/2008 AQ Team Validations Appendix 2 G0 to2.

Version /08/2008 Spec Calc

Version /08/2008 Spec Calc Validations  ASI – AQ Spec calc requests.  When the supply point AQ for the provided MPRN is less than 1, it would be rejected with MPQ  If all exchange details are provided and meter serial number is not provided, then STD  If all exchange details are provided and imperial indicator is not provided, then STD  If all exchange details are provided and exchange start reading date is null date, then STD  If all exchange details are provided and exchange end reading date is null date, then STD  If the start reading date is less than , then it would be rejected with STD  If the end reading date is less than , then it would be rejected with STD  If the exchange start reading date is less than , then it would be rejected with STD  If the exchange end reading date is less than , then it would be rejected with STD  Invalid Imperial Indicator (other than Y/N), rejects with STD  Invalid Reading Units (other than 1,10,100,1000,10000), rejects with STD  Invalid Exchange Reading Units (other than 1,10,100,1000,10000), rejects with STD  Invalid Reading factor (other than 0.01,0.1,1,10,100), rejects with STD  Invalid Exchange Reading factor (other than 0.01,0.1,1,10,100), rejects with STD  Start reading is greater than processing date, reject with STD  End reading is greater than processing date, reject with STD  Exchange Start reading is greater than processing date, reject with STD  Exchange End reading is greater than processing date, reject with STD  Number of dials out of permitted range (ideal range is 4 to 12), reject with STD  If the meter is Imperial, then reading factor and reading units must be in either of the following combinations: (0.01, 1), (0.1, 10), (1, 100), (10, 1000), (100, 10000). Reject if otherwise with MMO  If the meter is metric, then reading factor and reading units must be in either of the following combinations: (1, 1), (10, 10). Reject if otherwise with MMO  If the exchanged meter is Imperial, then reading factor and reading units must be in either of the following combinations: (0.01, 1), (0.1, 10), (1, 100), (10, 1000), (100, 10000). Reject if otherwise with MMO  If the exchanged meter is metric, then reading factor and reading units must be in either of the following combinations: (1, 1), (10, 10). Reject if otherwise with MMO  If the end reading is less than start reading, then reject with STD  If the start reading date is less than the earliest supply point start date, then reject with STD  If the supply point is end dated and if the end date is greater than the supply point end date, then reject with STD  If the exchange start reading date must be equal to end reading date, otherwise reject with STD  If the exchange end reading date is less than or equal to exchange start reading date, otherwise reject with STD  Sum of read TTZ and exchange read TTZ count should not go beyond 99, otherwise reject with STD  All the reading except the start reading date should be greater than competition effective date, otherwise reject with MRE 471  If the provided MPRN does not exist on the system, then reject with MPO Appendix 3

Version /08/2008 Is An AQ Amendme nt Required? AQ Amendments: Process Flow Xoserve Releases Notification Files To Shipper  SSP (NRQ)  Threshold Crossers (NRS)  LSP (NRM) Xoserve Releases Notification Files To Shipper  SSP (NRQ)  Threshold Crossers (NRS)  LSP (NRM) Shipper Analyses Information To Determine If Amendment is Required / Can Be Actioned Shipper Takes No Further Action xoserve Notifies Shipper of Revised AQ by 14th Sept: (  NRL  NRO) 1 st OCTOBER AQ BECOMES EFFECTIVE Shipper Submits Speculative Calculator Request File:  ASI File  T19 Record Shipper Submits Speculative Calculator Request File:  ASI File  T19 Record Spec Calc File Rejected with Rejection Reason:  ASO File will include S72 Rejection Record Spec Calc File Rejected with Rejection Reason:  ASO File will include S72 Rejection Record Shipper Receives Recalculated AQ Value Is AQ Acceptable and in Uniform Network Code Tolerances? Shipper Submits Amendment File as Per Spec Calc Response File:  AAI File  T17 Record Shipper Submits Amendment File as Per Spec Calc Response File:  AAI File  T17 Record xoserve Responds to Amendment File to Shipper: AAO File T18 Record AC, RJ or RF Outcome xoserve Responds to Amendment File to Shipper: AAO File T18 Record AC, RJ or RF Outcome Amendment File Rejected with Rejection Reason:  AAO File will include S72 Rejection Record Amendment File Rejected with Rejection Reason:  AAO File will include S72 Rejection Record Amendment File Accepted NO YES xoserve Responds with Speculative Calculation Response File to Shipper: ASO File T20 Record AC or RJ Outcome xoserve Responds with Speculative Calculation Response File to Shipper: ASO File T20 Record AC or RJ Outcome NO YES Is AQ Acceptable and in Uniform Network Code Tolerances? REJECT ACCEPT REJECT ACCEPT

Version /08/2008 Amendment Validations  AAI – AQ Amendment requests.  If the Meter Point is not part of any confirmation OR if the Shipper is not responsible for the provided MPRN, it would be rejected with SHI  If the provided confirmation reference is not the current live confirmation of the MPRN, it would be rejected with MPO  If smaller supply meter point is not eligible for AQ/WC amendment, then reject with STD  If an outstanding amendment referral exists for an MPRN, it would be rejected with AQA  If the requested AQ is less than 1, it would reject with STD  If the start reading date is less than , then it would be rejected with STD  If the end reading date is less than , then it would be rejected with STD  If the exchange start reading date is less than , then it would be rejected with STD  If the exchange end reading date is less than , then it would be rejected with STD  Invalid Imperial Indicator (other than Y/N), rejects with STD  Invalid Reading Units (other than 1, 10, 100, 1000, 10000), rejects with STD  Invalid Exchange Reading Units (other than 1, 10, 100, 1000, 10000), rejects with STD  Invalid Reading factor (other than 0.01, 0.1, 1, 10, 100), rejects with STD  Invalid Exchange Reading factor (other than 0.01, 0.1, 1, 10, 100), rejects with STD  Start reading is greater than processing date, reject with STD  End reading is greater than processing date, reject with STD  Exchange Start reading is greater than processing date, reject with STD  Exchange End reading is greater than processing date, reject with STD  Invalid Manual check flag (other than Y/N), reject with STD  Number of dials out of permitted range (ideal range is 4 to 12), reject with STD  If reading unit, reading factor and imperial indicator are inconsistent, then reject with MMO  If exchange reading unit, reading factor and imperial indicator are inconsistent, then reject with MMO  If the end reading is less than start reading, then reject with STD  If the start reading date is less than the earliest supply point start date, then reject with STD  If the supply point is end dated and if the end date is greater than the supply point end date, then reject with STD  If the exchange start reading date must be equal to end reading date, otherwise reject with STD  If the exchange end reading date is less than or equal to exchange start reading date, otherwise reject with STD  If exchange TTZ is 0 and if the exchange end reading date is less than exchange start reading date, otherwise reject with STD  Sum of read TTZ and exchange read TTZ count should not go beyond 99, otherwise reject with STD  If the shipper is not responsible for the MPRN, it would be rejected with SHI 0010

Version /08/2008 Amendment Validations  All the readings except the start reading date should be greater than competition effective date, otherwise reject with MRE 471  If the current and proposed market sector is Domestic, then 20% amendment tolerance rule is applied. Meter AQ changes will be accepted only if it lies beyond the tolerance range with respect to xoserve calculated initial AQ. Reject reason provided is AQA  The requested AQ value (provided in the file) and the derived AQ (using the parameters in the file) should match, otherwise reject with STD  If the MPRN is primary and if either the current or proposed market sectors is I&C, then refer the amendment, otherwise reject it with MPO  If the provided MPRN does not exist on the system, then reject with MPO  If the start read date is not later than AQ-WC backstop date, then reject with STD  If the end read date is earlier than xoserve calculated end read date, then reject with STD  Outstanding AQ/WC Appeal referral exists for this meter point, then reject with AML  Insufficient information to calculate AQ, then reject with AQA  Consumption period less than 6 month, then reject with MRE  Post code not found, then reject with POC  Start reading/date not consistent with UKLink, then reject with RRR  End reading/date not consistent with UKLink, then reject with RRR  Exchange start read/date not consistent with UKLink, then reject with RRR  Exchange end read/date not consistent with UKLink, then reject with RRR  TTZ count incorrect, then reject with RRR  Meter exchange not identified on amendment/appeal, then reject with RRR  Manual referral with insufficient supporting information, then reject with RRR  Appeal window not currently open for request, then reject with RRR  Exchange meter serial number not provided, then reject with STD  Exchange start reading date not provided, then reject with STD  Exchange end reading date not provided, then reject with STD  Occurrence of DM since start reading date, then reject with STD  Invalid value for number of dials or digits, then reject with STD  Meter point was not part of a live supply point for entire consumption period, then reject with STD  DM meter point cannot be appealed/amended to an AQ below the domestic threshold, reject with SPO G0 to 2.

Version /08/2008 Can An AQ Appeal Be Raised? Can an AQ Appeal be raised? AQ Appeals: Process Flow Shipper determines current AQ value is not reflective of actual consumption Shipper unable to raise AQ Appeal – AQ will be recalculated during next AQ Review – Shipper will have opportunity to raise Amend Shipper Submits Speculative Calculator Request File:  ASI File  T19 Record Shipper Submits Speculative Calculator Request File:  ASI File  T19 Record Spec Calc File Rejected with Rejection Reason:  ASO File will include S72 Rejection Record Spec Calc File Rejected with Rejection Reason:  ASO File will include S72 Rejection Record Shipper Receives Recalculated AQ Value Is AQ Acceptable? Shipper Submits Appeal File as Per Spec Calc Response File:  API File  T17 Record Shipper Submits Appeal File as Per Spec Calc Response File:  API File  T17 Record xoserve Responds to Appeal File to Shipper: APO File T18 Record AC, RJ or RF Outcome xoserve Responds to Appeal File to Shipper: APO File T18 Record AC, RJ or RF Outcome Amendment File Rejected with Rejection Reason:  APO File will include S72 Rejection Record Amendment File Rejected with Rejection Reason:  APO File will include S72 Rejection Record Shipper Receives Appeal File and submits re-nomination & confirmation using Appeal Reference NO YES xoserve Responds with Speculative Calculation Response File to Shipper: ASO File T20 Record AC or RJ Outcome xoserve Responds with Speculative Calculation Response File to Shipper: ASO File T20 Record AC or RJ Outcome NO YES Is AQ Acceptable? REJECT ACCEPT REJECT ACCEPT AQ Goes live on xoserve System on Confirmation Effective Date

Version /08/2008 Appeal Validations  Appeal process specific Validations  Reject with AML error in case there is a mismatch between provided appeal level (T41/T43) and detail level (T17/T21) confirmation reference numbers  If the Meter Point does not belong to the confirmation reference identified on the T41/T43 record, reject with AML  If the provided confirmation reference number does not exist on the system, reject with CNF  If duplicate T17/T21 records are sent under a same T41/T43 record. Reject with AML  If any of the meter point are rejected on the appeal then, the appeal is rejected with AML  There must be at least one T17 / T21 records to process the appeal, otherwise reject with APL  If the current and the proposed market sectors are Domestic, then reject the appeal with APL  If the WC appeal start date does not fall into the winter period, reject with WTC  If the WC appeal end date does not fall into the winter period, reject with WTC  If the current and proposed market sector is Domestic, then 20% appeal tolerance rule is applied. Meter WC changes will be accepted only if it lies beyond the tolerance range with respect to xoserve calculated initial AQ. Reject reason provided is WTC  Reject all AQ appeals between the period 01-AUG to 15-SEP as part of AQ review process. The appeals received during this period are rejected with STD  WC Appeals from Shippers are rejected with APL  If the provided confirmation is not in either LI or CO status, reject with CNF  If the Shipper is not the current registered owner of the MPRN, reject with SHI  If the provided nomination shipper reference is not valid, reject with CNF  DM meter point cannot be appealed/amended to an AQ below the domestic threshold, reject with SPO 00013