Working out if I should be registered as self-employed in the UK
As 'anonymous' already mentioned, I think the correct answer is to go see an accountant. That said, if you are already have to fill in a tax return anyway (ie, you're already a high rate taxpayer) then I don't see why it should be an issue if you just told HMRC of your additional profit via your tax return. I never was in the situation of being employed with a side business in the UK, only either/or, but my understanding is that registering as self employed is probably more suitable for someone who doesn't PAYE already. I might be wrong on this as I haven't lived in the UK for a couple of years but an accountant would know the answer. Of course in either case, make sure that you keep each an every scrap of paper to do with your side business. "Being self employed just means you fill out some more forms in your annual self assessment for your ""profit"" from being self employed.  Profit = all the money you receive, minus any tax deductible cost that you spent for making that money (and all the cost must be documented, which means you have a folder with all the receipts and keep it safe). You pay normal income tax on all the profit, which means it is just added to your taxable income. What you do with the profit is up to you; you don't pay yourself a salary, just take the money (make sure you leave enough to pay your taxes)."
As a sole trader you would fill out an Individual Tax Return and complete the Business and Professional Items Section P1 to P19, then enter the amounts from that section into Item 15 in the Supplementary Section of the Tax Return. Any business income as a sole trader will be included into your taxable income for the year together with other sources of income you may have earned in the same income year. Whether you get a tax refund will depend on the amount of taxable income you make, the amount of tax you have already paid in instalments throughout the year, and any tax deductions and tax offsets you can claim. Yes if you do it as a hobby, as it's still income. But it should be something you can offset against tax Either way, you shouldn't be doing this as you, you should either register as self employed or create a company. You register this income as self-employed income (or income of the company) and offset the expenses of running the server against tax. In the UK, companies (or self employed people, which are basically companies) pay tax on profit not income (unless VAT applies, in which case they're basically just passing the VAT on for their customers). Since you're not making a profit over the whole year (even if some months are profitable) you will pay no tax. Firstly, check your visa conditions (if you're not from the EU): http://www.ukcisa.org.uk/Information--Advice/Working/How-many-hours-can-you-work You do need to register for NI, but that's apparently streamlined into registering as self-employed: How to pay N.I contributions when both employed and self-employed? (Realistically, you can almost certainly get away with doing <£50 month in cash-in-hand jobs with no paperwork whatsoever, but in the very unlikely event of being caught it could result in being deported) You need to set your status as self-employed the day you started online work. If that date is a little ambiguous (as is usually the case with online business), you can start with the day you first made any money. Yes, you can deduct expenses from your revenue. But you have to be sure that the expenses were purely business related.  This is how it goes: You inform HMRC about the day you started work. HMRC will assign you a UTR (Unique Tax Reference) number. Depending on how much you make you might or might not need to pay Class 2 NI contributions. You'll need to tell HMRC how much you expect to earn in the current tax year. Finally, you'll need to complete a Self-Assessment at the end of the tax year. I highly recommend setting up a business banking account. Here is a link that discusses being part-time self-employed in the UK. "You probably know that the answer is, ""it depends"".  If this is truly a pin money type of operation, then perhaps sole trader is for you. I incline to using a limited company for two reasons, one optimistic and one pessimistic.  You are looking at a business to make some money with your talents.  If your business takes off, it's much easier to expand a LTD than a sole trader. Getting credit, dealing with suppliers, hiring people, all much easier.  And if things go well, you will be expanding.   The negative reason is that as a sole trader  (you) have unlimited liability for the debts of your enterprise. If you get sued, say your skincare line makes someone's face into a rash, you are on the hook for the whole amount. You don't want to torpedo your family if it goes bad. Being a limited company protects you from that. I can tell you that the overhead of running a small LTD is pretty light so long as you are meticulous about your record keeping. I had an LTD with two toddlers under my feet and it was perfectly doable to handle the paperwork." If I remember correctly, once you're about to exceed the threshold you really don't have a choice and have to register for VAT. As DumbCoder mentions, the quarterly VAT returns isn't that much of a hassle, plus if you fall under a certain threshold, you can sign up for the annual accounting scheme for VAT, which means you'll have to only put in a single return, but HMRC takes more payments out over the course of the year. This is what I did when I ran my own limited company in the UK. If this will be your sole income for the year, going self-employed is the best way to do this: So, here's how to go at it: Total cash in: £2000 Total Tax paid: £0 Admin overhead: approx 3 hours. Legit: 100%   :) Edit:  Can you tell me that in my case what are the required fields on the invoice? If you're non-VAT registered, there are no legal requirements as to what information you need to put on the invoice -it literally can be a couple of numbers on a napkin, and still be legit.  With that said, to make a professional appearance, my invoices are usually structured as follows: Left side: ( Sidenote: why client-specific incremental numbering? Why, so they can't make educated guesses to the number of clients I have at any given time :)  ) Right side: Center table: And so far, none of my clients missed any fields, so this should have everything they need to :) Hope this helps, but keep in mind, all of the above is synthetic sugar on the top -ultimately,  the relationship you share with your Clients is the thing you will (or will not) get paid for! Edit#2: The voices in my head just pointed out, that I've totally omitted National Insurance contributions in the above. However, and I quote HMRC: If your profits are expected to be less than £5,315 you may not have to pay Class 2 National Insurance contributions. Hence, this won't change the numbers above, either -just make sure to point this out during your registration in the office. The details of any bank accounts are irrelevant. If you're self-employed, you submit your tax return to HMRC at some point after the end of tax year. HMRC then tell you how much tax you owe and when payment is due, and you then pay it. HMRC don't have access to your bank accounts. Note that interest earned on a bank account is treated as taxable income, and banks normally automatically pay the tax due on your behalf, at the basic rate of 20%. If you're self-employed, you need to declare this income on your tax return. And in the case of a joint account, that interest is treated as being split equally. "It's pretty easy. In the Interview Setup for Ufile, check the box for ""Self-employment business income"". Then during the process of filling everything out, you'll get a Self-Employment screen. It'll ask for the name of your business, but just put your own name since you don't have one. For the 6-digit classification code, click the ? button and look through the list for the industry that best matches the one for whom you wrote the technical report. Or you can go with 711500: Independent artists, writers and performers. It doesn't really matter that much so don't worry if it's a poor match. It will also ask you for your income and expenses.   I don't know exactly what costs you might have incurred to write your report, but you can likely claim a very tiny amount of ""home office"" expenses. Costs like rent (or mortgage interest + property tax), utilities, and home insurance can be claimed, but they have to be pro-rated for the time you were actually doing the work, and are based on the amount of space you used for the work.  For example, if you paid $1000 rent and $200 utilities for the month in which the work was done, and it took you 20 of the 31 days in that month to actually do the work, and you used a room that makes up about 10% of the square footage of your home, then you can claim: $1200 * 20/31 * 0.1 = $77.42 for your home office expenses. If you also used that room for non-business purposes during that time, then you reduce it even further. Say, if the room was also used for playing video games 50% of the time, then you'd only claim $38.71" Yes. You must register for GST as well, if you will be making over the threshold (currently $60,000). That's probably a bonus for you, as your home office expenses will mostly include GST, but your income will most likely be zero-rated. Check with an accountant or with the IRD directly. Just be certain to put aside enough money from each payment to cover income tax, GST and ACC. You will get a very large bill in your second year of business. Yes, You will have to pay the taxes at least initially but you'll most probably get a refund when you will file returns depending upon the amount and tax brackets in the UK. I was just thinking ahead, can I apply for Limited company now, while fully time employed, and not take any business until I get a contract. Yes. You can open as many companies you want(assuming you are sane). There is no legal provisions regarding who can open a company.   What happens if I create a company and it has no turnover at all? Does this complicate things later? After you open a company, you have to submit your yearly statements to Companies House, whether you have a billion pounds turnover or 0. If you claim VAT that has also to be paid after you register for VAT. VAT registration is another registration different from opening a limited company. Is it the same if I decided to take a 1,2 or x month holiday and the company again will not incur any turnover? Turnover is year end, so at the year end you have to submit your yearly results, whether you took a 12 month holiday or a week's holiday. Is it a OK to do this in foresight or should I wait weeks before actually deciding to search for contracts. No need to open a limited company now, if you are so paranoid. Opening a company in UK takes 5 minutes. So you can open a company after landing a contract. For tax purposes you will need to file as an employee (T4 slips and tax withheld automatically), but also as an entrepreneur. I had the same situation myself last year. Employee and self-employed is a publication from Revenue Canada that will help you. You need to fill out the statement of business activity form and keep detailed records of all your deductible expenses. Make photocopies and keep them 7 years. May I suggest you take an accountant to file your income tax form. More expensive but makes you less susceptible to receive Revenue Canada inspectors for a check-in.  If you can read french, you can use this simple spreadsheet for your expenses. Your accountant will be happy. You would report the overall income on your T1 general income tax return, and use form T2125 to report income and expenses for your business.  Form T2125 is like a mini income-statement where you report your gross revenue and subtract off expenses.  Being able to claim legitimate expenses as a deduction is an important tax benefit for businesses big and small. In terms of your second question, you generally need to register for a business number at least once you cross the threshold for GST / HST. If you earn $30,000/year (or spread over four consecutive quarters) then charging GST / HST is mandatory; see GST/HST Mandatory registration.  There are other conditions as well, but the threshold is the principal one. You can also register voluntarily for GST / HST even if you're below that threshold; see GST/HST Voluntary registration.  The advantage of registering voluntarily is that you can claim input tax credits (ITC) on any GST that your business pays, and remit only the difference.  That saves your business money, especially if you have a lot of expenses early on. Finally, in terms of Ontario specifically (saw that on your profile), you might want to check out Ontario Sole Proprietorship.  There are specific cases in which you need to register a business: e.g. specific types of businesses, or if you plan on doing business under a name other than your own. Finally, you may want to consider whether incorporating might be better for you.  Here's an interesting article that compares Sole Proprietorship Versus Incorporation.  Here's another article, Choosing a business structure, from the feds. Only if your work on the side is making you at least £60,000 profit a year. The overheads are just not worth it if you make less. Working as a sole trader, you can still claim for expenses incurred in the course of your business. You can also claim a percentage of your computer costs, even though you may use the computer for gaming. This is not unreasonable as the computer is necessary for your work. The Inland Revenue accept the fact that some assets are part work-related. In your case, as a web and mobile phone developer, I expect the percentage to be at least half, if not a lot more. If you need to travel in the course of your work you can claim a percentage for your car. You can include other small expenses such as telephone, stationery, electricity etc but don't go overboard. The important point to remember is that you must be able to defend the expenses claimed as work-related, so long as you can do this there is no problem. Remember to keep good records of all your expenses. This is on-going throughout the year and is much more work than filling out your tax return. The software on the IR self-assessment site is excellent, so it's conceivable that you may not need an accountant if you are prepared to do your own tax return. However, if you feel unsure employ an accountant initially and take it from there.