Most employers and super funds are complying with superannuation guarantee (SG) obligations, but latest ATO data shows there are still some breaching SuperStream standards.
Over 2016-17, SuperStream processed 135 million contributions - about five million more than the prior corresponding period, according to the SuperStream annual benchmarking report.
Since 1 July 2014, the overall rate of contributions complying with the standards has also been growing progressively, the report said.
By the end of the June 2017, about 94% of all employer contributions were received electronically - about 5% higher than the previous year.
The proportion of non-complying employer contributions has steadily declined over the reporting period. By June 2017, 2.21 million contributions (6.1%) did not align with SuperStream standards, an improvement from 10.1% year-on-year.
Businesses found to be non-compliant make contributions using a combination paper-based, electronic and hybrid processes, which do not meet SuperStream standards.
When the ATO discussed non-compliance with individual funds and businesses, it highlighted several patterns have emerged.
Electronic payments such as BPAY and direct debits is common among micro-businesses, while a small amount of re-work is undertaken for the few that use cheques.
A large proportion of non-SG payments are also failing to report items such as insurance only amounts paid by employers, it said.
The ATO explained this could be due to the "more protracted nature" of transitioning to SuperStream as the smaller funds manage their way through the change.
But based on relative size, the top 20 funds account for most of non-conforming contributions (76.8%), the ATO said. Small-sized funds also tend to carry a relatively higher load of non-compliance relative to their contributing membership.
Launched in 2012, SuperStream mandates employers or businesses to pay employee SG contributions to super funds, and provide the money and data in an electronically format.
Self-managed super funds and APRA-regulated funds also fall within the SuperStream remit.
Prior to the 2010 Cooper Review, in which SuperStream arose, it should be noted that there were no exact measures of contribution volumes or the split between electronic and manual methods, the ATO said.