1. TAX CODE
If you think your tax code is wrong, find your tax reference and national insurance number on a payslip, HMRC letter, certificate of tax paid or PAYE coding notice and contact HMRC as soon as possible.
2. HMRC CHARTER
Quote HMRC’s charter, which can be found on its website, hmrc.gov.uk/ charter. The charter vows to respect taxpayers and act professionally in dealing with them.
3. TAX CALCULATIONS
If you have underpaid tax but are struggling to understand the calculations involved, visit the Low Income Tax Reform Group (LITRG) website at litrg.org.uk and click on PAYE underpayments 2010/2011 for helpful information.
4. CHALLENGE THE NUMBERS
If you think that your tax has been miscalculated and that you have not underpaid, write to HMRC as quickly as possible, ideally within 30 days. Sample letters can be found on the LITRG website.
5. HIRE HELP
If your negotiations with the taxman are failing, you might consider hiring an accountant to deal with HMRC on your behalf. Alternatively, you could request an internal review from HMRC and, subsequently, a firsttier tribunal if no satisfactory conclusion is reached. For more information, visit hmrc.gov.uk/complaints-appeals/how-to-appeal/direct-tax.htm