In news that will do little to dispel popular stereotypes about the productivity of fans of certain drugs, the Cannabis is Safer than Alcohol political party has been fined for repeatedly filing its accounts late.

The party must pay a total of £23,000 for what the Electoral Commission said were “numerous failures” to comply with rules on reporting political finances.

Cannabis is Safer than Alcohol (Great Britain) was fined £10,000 for the late filing of two quarterly reports on donations, and one set of accounts, and for not keeping proper accounts, the commission said in a statement.

The separate Northern Ireland branch of the party – which won the right to a party political broadcast in the region last year after fielding candidates in four seats – has been fined £13,000.

It had failed to provide two quarterly donations reports, or its spending return for the Northern Ireland assembly election in May 2016, filed one loans report and one set of accounts late, and failed to keep proper accounts.

Such issues are treated very seriously by the Electoral Commission, which has powers under the 2000 Political Parties, Elections and Referendums Act to ensure parties abide by the rules over donations and spending.

Cannabis is Safer than Alcohol, or Cista, was launched before the 2015 general election, in which it fielded 32 candidates across the UK, winning just over 8,400 votes in total. It is chaired by Paul Birch, who made a large sum from the sale of the social network Bebo, and who invested £100,000 in the party.

Cista is seeking a royal commission on drug law reform and a recognition of the medical benefits of cannabis.

Speaking to the Guardian last year, Birch said many of Cista’s supporters were long-term users of opiate medicines who were sick of the side-effects of the drugs. “Taking cannabis enables them to have pain relief and have a normal life,” he said.

Cista also put up a candidate in the 2016 London mayoral election, with Lee Harris winning more than 20,000 votes. However, since then the party has hit regulatory difficulties. It has previously paid fines to the Electoral Commission for other offences, and in November last year was removed from the register of political parties after failing to complete an annual registration confirmation.

Bob Posner, the director of party finance for the Electoral Commission, said parties had to submit up-to-date records so voters could see who was funding them and by how much.

He said: “We had significant concerns about this party’s willingness to comply with the rules and the loss of transparency as a result of its unprecedented history of non-compliance. The fines issued in this case reflect the serious impact that this can have on voter confidence.”