Time is running out for self-assessment tax payers who want to get the Inland Revenue to calculate their tax bill.

The deadline for most taxpayers who want their liability for the 2001-02 tax year worked out for them passes on 30 September.

After that, tax payers will have to employ an accountant or work out for themselves how much they owe the taxman.

Self-assessment tax payers that miss the September deadline have to return their forms with full payment to cover what they owe by 31 January.

Exception to the rule

In an effort to get people filing their tax returns online, the Inland Revenue has extended the traditional 30 September deadline for a portion of e-filers who want their tax calculated for them.

The extension is for people with simple tax affairs, who do not have any more than �2,000 tax to pay under self assessment, and are normally taxed through the pay as you earn (PAYE) code.

They now have until 30 December 2002 to file their tax return over the internet.

The Revenue will work out how much they need to pay and then adjust their tax code accordingly.

This is a limited ruling, and people who want to file paper returns must stick to the traditional 30 September deadline.

Late penalties

Missing this deadline carries an automatic �100 fine, with interest charged on any overdue tax.

Main groups self-assessment applies to

Self-employed Trustees or personal representatives Business partners Company directors, employees and pensioners with complex tax affairs

If the tax payment is still not made by 28 February, an additional surcharge of 5% on the outstanding balance is imposed.

Self-assessment forms received by the Inland Revenue after next January will be open to a full investigation by the taxman for up to 15 months.

The normal enquiry period for forms filed between September and the end of January is only 12 months.

Millions miss deadline

Self-assessment affects 9.5m tax payers with more complicated tax affairs.

The Inland Revenue told BBC News Online that 4.8m missed the September deadline last year.

What is more, 800,000 failed to file a return by 31 January and were fined.

Chas-Roy Chowdury, head of taxation at the Association of Chartered Certified Accountants (ACCA), believes self-assessment tax payers are best to get their skates-on and make the September deadline rather than waiting.

"The sooner the forms are sent in, the sooner tax payers will discover whether they are entitled to tax rebates," he said.

Tax payers can fill out self-assessment forms online.

One advantage of doing a tax return online is that the Revenue will calculate your liability for you.

This can be done by going to the Inland Revenue website at www.inlandrevenue.gov.uk to file their tax return.