The accounts for challenger energy provider Solarplicity are listed as “overdue” on the Companies House website, prompting concerns the supplier is in difficulty.

Overdue accounts or extending an accounting period, as seen with a recently failed energy supplier, may be a sign that the company is in trouble according to industry sources.

A source told Utility Week there was a “concerning trend” of suppliers who are late filing their accounts, or who reduce their accounting year end by one day to buy an extra three months to file their accounts.

The source added: “In our experience this can be linked to disagreements with auditors over the state of the accounts – or the accounts not being in a fit state to file.”

Another source confirmed the accounts could be overdue due to a disagreement with the auditors, namely they are not comfortable with “one or more specific accounting treatments” the company has applied to its accounts.

In response to the claims a Solarplicity spokesperson said there was no specific reason for the delay.

The spokesperson said: “The statements are currently sitting with the auditors to sign off.

“They have not suggested any changes to what Solarplicity originally submitted.

“As such, we expect to be able to be in a position to sign off these accounts very soon.”

Last week Solarplicity was slapped with a provisional order by Ofgem and banned from taking on new customers for up to three months until it resolves customer service issues.

The provisional order also prevents the supplier from increasing direct debits for “vulnerable customers”.

The regulator has warned that if the company fails to improve it could result in the revocation of its supplier licence.

Economy Energy was another supplier which extended its accounting period according to Companies House. This supplier went into credit default and ceased trading last month.

Like Solarplicity, it too was subject to a provisional order banning it from taking on new customers.

In January consumer group Which? revealed Solarplicity ranked bottom in its annual satisfaction survey. The supplier was also scored just two stars out of five in the latest Citizens Advice customer service rating table.

Furthermore the Energy Ombudsman revealed the Hertfordshire-based supplier was subject to 1,035 investigations into complaints last year.

Alex Neill, Which? managing director of home services, said in response to Ofgem’s provisional order: “Solarplicity finished rock bottom in our annual energy satisfaction survey, with scores of customers complaining about appalling customer service over the phone and online – so it’s right that the regulator is stepping in.

“As millions of energy customers brace themselves for yet another eye-watering set of price hikes, this should also serve as a warning to all firms letting their customers down with shoddy service, billing and payment problems or poor complaints handling that they need to up their game.”

Solarplicity said Ofgem’s decision “was made on old historical data” and that the supplier has made “vast improvements” to its customer service.