If you're struggling with the tax demand that's landed on your doormat recently, help is at hand from the Inland Revenue.

They've put together a free self-assessment Tax Calculator, developed from one they use internally themselves, to help you complete your 1999/2000 self-assessment return or check the entries you make. Do bear in mind though that the Inland Revenue takes no responsibility for the figures you enter into the calculator.

To view the calculator, you need to have access to Microsoft Excel version 97 or later. The completed forms can be printed out and sent off, or you can file your return using the Internet Filing service on the revenue website. If you send your 1999/2000 tax return over the Internet and pay electronically by the due date, you should qualify for a one-off £10 discount.

Tax demands for the year 1999/2000 are due to be paid by 31 January, but to use the calculator you need to be quick - somewhat bizarrely, the revenue are insisting on sending out the login IDs needed to submit your return over the Internet through the post! The Inland Revenue are however looking at providing an online version of the calculator for the next financial year.