The data dump of information about political donations on Friday gave a glimpse of the flow of finances into party coffers.

But it also served as a reminder of how opaque and inadequate the system is.

It's February 2019, but it has only just been revealed what donations political parties received as far back as July 2017.

Since then, there have been state elections, by-elections, royal commissions and a myriad of national debates affecting the very industries that are funding the federal government and opposition.

Donations worth less than $13,800 dollars are escaping scrutiny as they don't have to be declared.

It's possible large donations are being made with multiple cheques just under that threshold — but it's not possible to tell.

Donations can be funnelled through bodies affiliated with political parties that, for example, accept payments for seats at fundraising events.

These funds are then registered by the political parties as receipts from the affiliated body and the original source remains hidden.

The Grattan Institute has analysed the 2017-18 donations data released on Friday by the Australian Electoral Commission and found $56 million of income to the Liberal and Labor parties that could not traced, because they're not required to disclose where it comes from.

"This is almost an annual reminder of how flawed our political donations regime is," said Danielle Wood, the Grattan Institute's program director.

It would only take updated laws and a technology upgrade to fix the problems.

Queensland, South Australia, Victoria and New South Wales have laws requiring donations to be declared within a month, or in some circumstances a week, of them being made.

Ms Wood said the Federal Parliament should be following the lead of the states.

"Really, there is no reason why the Commonwealth could not be giving us substantially more timely data than we currently get," she said.

"We need to ask ourselves: What is it that government doesn't want us to know?

"There are very simple steps that could make this data a lot more transparent and it only requires political will to make it happen."

Lowering the disclosure limit would be straightforward

Victoria, for example, recently passed laws forcing all donations over $1,000 to be declared and capping them at $4,000 over 4 years, albeit with a corresponding increase in public funding for political parties.

The Greens want a similar cap passed in the Federal Parliament.

Ms Waters wants the $13,800 declaration cap lowered. ( ABC News: Nicholas Haggarty )

"It's a small contribution, it wouldn't be enough to influence policy outcomes," Greens spokeswoman for democracy, Senator Larissa Waters, said.

"People can still express their support for the sorts of values they want in parliament but it's not enough to buy an outcome or to buy off a political party.

"I think it is disgusting that industries can buy a policy outcome. That's not how our democracy is meant to work."

The Greens also want an outright ban on donations from the mining, gambling, alcohol, property and banking sectors.

They won't find political support in parliament for a change as radical as sector-specific bans.

But even more modest efforts to improve the disclosure system have failed to pass parliament in recent times.

Late last year, the major parties passed legislation to ban foreign donations, a significant political reform.

But at the same time, the parliament rejected amendments that would have seen the donation threshold lowered to $1,000 and real-time disclosure introduced.

The political will was lacking, once again raising the question: What is it the political parties don't want us to know?