The accounting profession has reacted with shock to the shortening of self-assessment tax deadlines, warning it could affect the working practices of tax advisers.

Online filing of self-assessment returns is set to move back from 31 January to 30 November from 2008, while paper returns must be completed by 30 September.

The announcement, made as part of the launch of the Carter Review, has been fully accepted by HM Revenue & Customs as the blueprint for its online services.

But accountants say the move will put more pressure on them and their clients to gather and process documents in time.

‘I can’t see a single good reason for doing it,’ said Paul Aplin, deputy chairman of the ICAEW’s tax faculty.Smith & Williamson national tax director Francesca Lagerberg said a combination of Lord Carter’s plans to increase the use of online filing and new deadlines could place extra pressure on HMRC’s IT systems.

Lord Carter defended his review, saying it was part of a wide consultation that incentivised accountants to use online filing.