How to get help doing tax return calculations
Self assessment can be as easy entering your total earning and entering your total expenditure. All the information you need is held on the HMRC website and their staff are happy to answer any questions you may have either by phone or email. The tricky part comes from knowing what is deductible and what is not. The best advice I can give is to start a database (I use Excel) and enter the headings for the date, the name of the job, the agency/company the amount invoiced and the amount received. The one you are concerned with is the amount received which you need a total for at the end of the tax year from April. Once you have your total for money received you need to deduct your total expenses. Be sure to keep receipts for all payments you make for your business, bus/train tickets etc. At the time of writing this the calculation for mileage driven to and from work was 40p per mile so I have a heading for the postcode and total mileage per job. I then use excel to make the calculation for me with the formula =(mileage)*0.4. This then gives me the total deduction you can make for your car for this journey. If you have a personal mobile phone that you use for business you can claim part of the costs as a deduction. I spoke to an advisor at HMRC and their policy is that you have to judge the percentage you use that phone for business. If it is 50/50 the calculation is pretty easy so that is really your own judgement. Be sure to put down any training you have done for your career also as well as website and agency fees and union costs. Most important of all be honest, genuine mistakes are usually dealt with as such and you will just be required to pay the difference whereas deceiving the HMRC will get you in very hot water. That's how they got Al Capone after all.