I have 2 part-time jobs, totalling 40 hours per week (20 hours for each employer) and my employee tax code with one employer is 1000L and with the other it is 825L. Does this mean I have a tax threshold personal allowance of £18250 per annum? If so, has the tax office made a mistake or is there a reason for issuing these codes (eg. an adjustment due to being over-taxed during previous tax year, having worked 2 part-time jobs over several years)