Market operator service (MOS)
Market Operator Service (MOS)
For the purposes of rule 398(1) of the National Gas Rules (NGR), AEMO publishes a notice requesting MOS increase offers and MOS decrease offers from Short Term Trading Market (STTM) Shippers for each STTM pipeline.
An eligible trading right holders must comply with the requirements of rule 399 and rule 400 of the NGR in respect of its MOS increase offer or MOS decrease offer.
The STTM participant webexchanger user guide, STTM Participant Build Pack, STTM Participant Build Pack Business Validation Addendum explain how to make compliant MOS offers.
These documents can be found here.
MOS estimates
Monthly MOS estimates will be published on a quarterly basis in the following format. The MOS estimate publish date represents the latest date by which the MOS estimates should be published.
| Monthly MOS Estimates Released Quarterly | MOS Estimate Publish Dates |
|---|---|
| June, July, August | Estimated early April (40 business days before 1 June) |
| September, October, November | Estimated early July (40 business days before1 September) |
| December, January, February | Estimated early October (40 business days before 1 December) |
| March, April, May | Estimated early January (40 business days before 1 March) |
MOS estimates can be found in the following section MOS Estimates Reports and Data.
Methodology for determining MOS estimates
This is the methodology for determining MOS estimates required under clause 5.2(f) of the STTM Procedures.
Methodology for determining MOS estimates v3.0
MOS estimate reports and data
The MOS estimates reports and data, required under rule 397(1) of the NGR, for each MOS period can be found via the following link:
MOS periods and MOS Offer Submission Dates
STTM Shippers must, for the purpose of rule 398(2)(b), submit final MOS increase offers and MOS decrease offers to AEMO by 5:00 pm on the 11th gas day before the start of a MOS period. These offers must be submitted into the STTM webexchanger in accordance with the STTM participant webexchanger user guide.
| MOS Period Start Date | MOS Period End Date | MOS Offer Submission Date* |
|---|---|---|
| 1 January | 31 January | 21 December |
| 1 February | 28 February** | 21 January |
| 1 March | 31 March | 18 February** |
| 1 April | 30 April | 21 March |
| 1 May | 31 May | 20 April |
| 1 June | 30 June | 21 May |
| 1 July | 31 July | 20 June |
| 1 August | 31 August | 21 July |
| 1 September | 30 September | 21 August |
| 1 October | 31 October | 20 September |
| 1 November | 30 November | 21 October |
| 1 December | 31 December | 20 November |
* All MOS offer submission are due by 17:00 hrs AEST on the date listed.
** In a leap year the MOS period ends on 29 February and the MOS offer submission date is 19 February
MOS stacks
All MOS stacks for current and future MOS periods are published to the AEMO webpage in the following format: