The monstrous sums of underpayments that have emerged in 2019 reflect a shabby disregard for employees among the companies involved.

Just as bad, they show there is not enough in the way of penalties to scare employers into making sure their staff get paid appropriately.

Once again, a hefty slice of corporate Australia finds itself behind public opinion on a matter that hurts the hip pockets of everyday people.

The errors aren't confined to small, unprofessional or unscrupulous employers. It's the likes of Woolworths, Wesfarmers, Qantas and Bunnings - otherwise reputable and even iconic companies - that have underpaid workers.

Woolworths says it has so far identified 5700 current staff it has underpaid for as long as nine years, and estimates it owes as much as $300 million.

Qantas owed thousands of dollars in backpay after discovering an "embarrassing" bungle that saw it short-change some workers and over-pay others. Wesfarmers left staff underpaid an estimated $15 million.

To add to the disappointment, some have made the excuse that Australia's industrial relations system needs change.

The complaint just doesn't sound reasonable given the situation, and there's a "dog ate my homework" ring to it. It's rightly been pointed out that companies have little trouble managing complexity in other parts of their business. Paying workers should be no harder.

If the shoe was on the other foot, employees could expect little patience from their bosses should they repeatedly fail to meet their duties and then complain it's all too hard.

The reality is this would be unlikely to occur, because workers don't have that power and luxury. Corporations do, if they indulge in excuses for their failures.

Attorney-General Christian Porter says the government will hit companies with new penalties if they underpay their staff.

His tough words may sound surprising from a pro-business, Coalition minister, but they only confirm corporations have put themselves in an indefensible spot.

Mr Porter's suggestion to ban directors of companies who underpay their workers from sitting on boards has merit. The penalty would block corporate leaders from the lucrative pay packets that come with such roles.

It provides a "stick" that would create pressure from the top of companies to create more thorough payroll habits. There's a "get-tough" element to the idea. It promises a form of justice that is crude but appealing.

The regulation is obviously designed to appeal to the public. Its merits extend further. Targeting directors could bring decisive change without resorting to penalties that would filter down unfairly to shareholders.

There are other changes the government can make. Company directors should bear responsibility for such errors, but there are other pressure points that could make companies pay better attention to the rules. Senior managers could be made to face repercussions.

While companies have used the industrial relations system wrongly as an excuse, it is true the government can't unpick the revelations of unpaid wages from Australia's workplace laws. In this case, the rules have obviously left employees vulnerable.

In an era of declining union influence, both workers and governments need to rethink how best to prevent the kind of behaviour revealed this year.

The Coalition is unlikely to give unions power to look at company pay records. If it doesn't like that idea, then it should still consider other ways to keep tabs on the human resources units of companies that have not proven competent, reliable or trustworthy.

The government will find much public support for new regulations and penalties. It should use this to employees' advantage.