Three DUP MLAs have been fined after failing to declare a donation within the set timeframe.
Jonathan Buckley, Michelle McIlveen and William Humphrey have each been fined £200 by the Electoral Commission.
They were found to have failed to report a donation within 30 days.
All three paid their fines in early July.
A DUP spokesman said: “A declaration was made to the NI Assembly’s register of interests but the Electoral Commission was not notified. This was an oversight and has been corrected.”
In a statement, the Electoral Commission said it has also concluded three investigations into failures to comply with the Political Parties, Elections and Referendum Act (PPERA) by three regulated donees, relating to donations accepted prior to July 1 2017.
It has imposed penalties of £250, £300 and £600 on these three regulated donees. The deadline for payment or appeal is September 9 2019.
The commission is unable to disclose any information concerning donations to Northern Ireland recipients made prior to July 1 2017.
Louise Edwards, Director of Regulation, has urged the law to be changed to allow the disclosure of this information.
“We regret that we remain unable to disclose information about donations prior to July 2017,” she said.
“We continue to urge the UK Government to bring forward legislation that will enable us to publish information on donations from January 2014.
“This would give transparency and confidence to voters in Northern Ireland.”