There is no single answer, because G98 and G99 run on opposite clocks. One has a deadline that starts when you finish. The other has a queue that starts when you submit.
G99: submit when the job is won
A G99 application has to be approved before you install. The network operator has a statutory window to respond — commonly up to 45 working days for a standard distributed generation application — and that window runs on their schedule, not yours.
So the application should go in at the point the job is won, not the week before the scaffold arrives. Submitting early costs nothing. Submitting late costs you the install date.
Installing ahead of approval is the expensive version of this mistake. If the operator comes back requiring an export limit, a different connection arrangement or a reinforcement contribution, you're modifying a commissioned system at your own cost.
G98: notify within 28 days of commissioning
A G98 notification is the reverse. Nothing blocks the install, so nothing forces the paperwork — which is precisely why it slips. The clock starts at commissioning and runs for 28 days.
The practical advice: file it the same week you commission, while the details are still in front of you.
Get the application in early
Send us the job as soon as it's won and we'll have it submitted inside one to two working days.
Submit an Application