The actual thresholds
Under Schedule 4 of the Food Standards Code, any nutrition content claim about dietary fibre requires a serving of the food to contain at least 2g of dietary fibre, unless the claim is specifically about low or reduced fibre. That 2g figure is the general condition underneath every fibre claim, not a claim in itself.
Two specific descriptors sit above that general condition. A "good source" claim requires at least 4g of dietary fibre per serving. An "excellent source" claim requires at least 7g per serving. There's also an "increased" claim, which requires the reference food to contain at least 2g of fibre per serving and the product carrying the claim to contain at least 25% more fibre than that reference food.
"High fibre" isn't a defined term
It's common shorthand, and it's not wrong in spirit, but "high fibre" has no gram threshold of its own in the Food Standards Code. The Code's actual graduated descriptors are "good source" (4g) and "excellent source" (7g). A product marketed as "high fibre" is, in regulatory terms, almost certainly making an excellent source claim, or should be, if it's using the phrase accurately.
If a label says "high fibre" without meeting at least the excellent source threshold, that's a marketing phrase riding on a defined claim's credibility without meeting its bar.
Why the thresholds are set per serving, not per 100g
Fibre content claims are assessed on the amount in a serving of the food, not the amount per 100g. This matters because serving sizes vary enormously between product categories. A food with a modest fibre density but a generous serving size can clear the 4g or 7g bar more easily than a fibre-dense food sold in small servings. Reading the claim in isolation, without checking the declared serving size on the same pack, can be misleading either way.
What this means when you're reading a label
A bare fibre content claim, without "good source" or "excellent source" language, tells you the product contains at least 2g of fibre per serving and nothing more precise than that. "Good source" narrows it to at least 4g. "Excellent source" narrows it to at least 7g. None of these figures are a personal target. They're minimum thresholds a manufacturer has to clear before making that specific claim, set by regulation rather than by nutrition science's higher recommended intakes.