Taxable income on full-time job + business earnings
In Australia, any income you earn is taxable despite where it came from. Using your example your taxable income is $70,000. Keep in mind that with a business even as a sole trader any business expenses that contribute to the earning of your business income is deductible, reducing the final amount of tax you'll have to pay.  The ATO website has lots of good information and examples to look at including tax rates.  If your total income is pushing  into a higher tax bracket over 30c tax per $1 earned, it may be worth looking at shifting your business to operate under a company structure that just has a fixed tax rate around 30c per $1.  That said, for me, I don't want the paperwork overhead of a company yet so I'm running my side business as a sole trader too. I'd rather do that and keep it easy for now while my business gets profitable that waste time on admin structures for tax reasons even if in the shortterm it may mean slightly higher tax. In the end, you only pay tax on profit (income minus expenses) as opposed to raw/gross income.  For more info there are good books in the bookshops or local library (to read free) on starting a business on the side while still working. They discuss these issues too. I'm not sure I am fully understanding the nuance of your question, but based on your answer in the comments you and your business are not separate legal entities. So your income is the full $70K, there is no distinct business to have income. If you clarify your question to include why you want to know this I might be able to give a more meaningful answer for your situation. Possible alternative: In my case, the part-time locksmithing is a small enough portion of my I come that I just submit it as hobby income, rather than trying to track it as a separate entity.
Please do not focus solely on income tax, and ignore all of the other taxes that businesses need to pay.  Payroll taxes for example.  If I make $15/hr, I cost my employer more than this in reality. "The real question you're asking is how you can work for your business. You cannot. Whether your ""friend"" pays you or not is entirely irrelevant. Claiming your work-related earnings as interest/dividend will make it also a tax fraud, in addition to the immigration violation (i.e.: not only deportation but also potentially jail time)." Alright, IRS Publication 463: Travel, Entertainment, Gift, and Car Expenses Business and personal use. If you use your   car for both business and personal purposes,   you must divide your expenses between business   and personal use. You can divide your expense   based on the miles driven for each purpose. Example. You are a sales representative   for a clothing firm and drive your car 20,000   miles during the year: 12,000 miles for business   and 8,000 miles for personal use. You can   claim only 60% (12,000 ÷ 20,000) of the cost of   operating your car as a business expense Obviously nothing helpful in the code.  So I would use option 1, weight the maintenance-related mileage by the proportion of business use.  Although if you use your car for business a lot (and perhaps have a spouse with a car), an argument could be made for 3.  So I would consider my odds of being audited (even lower this year due to IRS budget cuts) and choose 1 or 3. And of course never throw anything away until you're room temperature. "It doesn't generally matter, and I'm not sure if it is in fact in use by the IRS other than for general statistics (like ""this year 20% of MFJ returns were with one spouse being a 'homemaker'""). They may be able to try and match the occupation and the general levels and types of income, but for self-employed there's a more precise and reliable field on Schedule C and for employees they don't really need to do this since everything is reported on W2 anyway. So I don't think they even bother or give a lot of value to such a metric. So yes, I'm joining the non-authoritative ""doesn't matter"" crowd." You need to register as self-employed with HMRC (it is perfectly fine to be self-employed and employed by an employer at the same time, in exactly your kind of situation). Then, when the income arrives you will need to declare it on your yearly tax return.  HMRC information about registering for self-employment and declaring the income is here: https://www.gov.uk/working-for-yourself/overview There's a few extra hoops if your clients are outside the UK; the detail depends on whether they are in the EU or not. More details about this are here: https://www.gov.uk/online-and-distance-selling-for-businesses/selling-overseas . "When I have a question about my income taxes, the first place I look is generally the Giant Book of Income Tax Information, Publication 17 (officially called ""Your Federal Income Tax""). This looks to be covered in Chapter 26 on ""Car Expenses and Other Employee Business Expenses"". It's possible that there's something in there that applies to you if you need to temporarily commute to a place that isn't your normal workplace for a legitimate business reason or other business-related travel. But for your normal commute from your home to your normal workplace it has this to say:  Commuting expenses.   You cannot deduct the costs of taking a bus, trolley, subway, or taxi, or of driving a car between your home and your main or regular place of work. These costs are personal commuting expenses. You cannot deduct commuting expenses no matter how far your home is from your regular place of work. You cannot deduct commuting expenses even if you work during the commuting trip." There might be a problem. Some reporting paperwork will have to be done for the IRS, obviously, but technically it will be business income zeroed out by business expense. Withholding requirements will shift to your friend, which is a mess. Talk to a licensed tax adviser (EA/CPA) about these. But the immigration may consider this arrangement as employment, which is in violation of the visa conditions. You need to talk to an immigration attorney. "Take a look at IRS Publication 15. This is your employer's ""bible"" for withholding the correct amount of taxes from your paycheck. Most payroll systems use what this publication defines as the ""Percentage Method"", because it requires less data to be entered into the system in order to correctly compute the amount of withholding. The computation method is as follows: Taxes are computed ""piecewise""; dollar amounts up to A are taxed at X%, and then dollar amounts between A and B are taxed at Y%, so total tax for B dollars is A*X + (B-A)*Y. Here is the table of rates for income earned in 2012 on a daily basis by a person filing as Single: To use this table, multiply all the dollar amounts by the number of business days in the pay period (so don't count more than 5 days per week even if you work 6 or 7). Find the range in which your pay subject to withholding falls, subtract the ""more than"" amount from the range, multiply the remainder by the ""W/H Pct"" for that line, and add that amount to the ""W/H Base"" amount (which is the cumulative amount of all lower tax brackets). This is the amount that will be withheld from your paycheck if you file Single or Married Filing Separately in the 2012 TY. If you file Married Filing Jointly, the amounts defining the tax brackets are slightly different (there's a pretty substantial ""marriage advantage"" right now; withholding for a married person in average wage-earning range is half or less than a person filing Single.). In your particular example of $2500 biweekly (10 business days/pp), with no allowances and no pre-tax deductions: So, with zero allowances, your employer should be taking $451.70 out of your paycheck for federal withholding. Now, that doesn't include PA state taxes of 3.07% (on $2500 that's $76.75), plus other state and federal taxes like SS (4.2% on your gross income up to 106k), Medicare/Medicaid (1.45% on your entire gross income), and SUTA (.8% on the first $8000). But, you also don't get a refund on those when you fill out the 1040 (except if you claim deductions against state income tax, and in an exceptional case which requires you to have two jobs in one year, thus doubling up on SS and SUTA taxes beyond their wage bases). If you claim 3 allowances on your federal taxes, all other things being equal, your taxable wages are reduced by $438.45, leaving you with taxable income of $2061.55. Still in the 25% bracket, but the wages subject to that level are only $619.55, for taxes in the 25% bracket of $154.89, plus the withholding base of $187.20 equals total federal w/h of $342.09 per paycheck, a savings of about $110pp. Those allowances do not count towards other federal taxes, and I do not know if PA state taxes figure these in. It seems odd that you would owe that much in taxes with your withholding effectively maxed out, unless you have some other form of income that you're reporting such as investment gains, child support/alimony, etc. With nobody claiming you as a dependent and no dependents of your own, filing Single, and zero allowances on your W-4 resulting in the tax withholding above, a quick run of the 1040EZ form shows that the feds should owe YOU $1738.20. The absolute worst-case scenario of you being claimed as a dependent by someone else should still get you a refund of $800 if you had your employer withhold the max. The numbers should only have gotten better if you're married or have kids or other dependents, or have significant itemized deductions such as a home mortgage (on which the interest and any property taxes are deductible). If you itemize, remember that state income tax, if any, is also deductible. I would consult a tax professional and have him double-check all your numbers. Unless there's something significant you haven't told us, you should not have owed the gov't at the end of the year." You are in business for yourself. You file Schedule C with your income tax return, and can deduct the business expenses and the cost of goods sold from the gross receipts of your business. If you have inventory (things bought but not yet sold by the end of the year of purchase), then there are other calculations that need to be done.  You will have to pay income tax as well as Social Security and Medicare taxes (both the employee's share and the employer's share) on the net profits from this business activity. Checkout the worksheet on page 20 of Pub 535.  Also the text starting in the last half of the third column of page 18 onward. https://www.irs.gov/pub/irs-pdf/p535.pdf The fact that you get a W-2 is irrelevant as far as I can see.  Your self-employment business has to meet some criteria (such as being profitable) and the plan needs to be provided through your own business (although if you're sole proprietor filing on Schedule C, it looks like having it in your own name does the trick).  Check the publication for all of the rules. There is this exception that would prevent many people with full-time jobs on W-2 from taking the deduction: Other coverage. You cannot take the deduc­tion for any month you were eligible to partici­pate in any employer (including your spouse's) subsidized health plan at any time during that month, even if you did not actually participate. In addition, if you were eligible for any month or part of a month to participate in any subsidized health plan maintained by the employer of ei­ther your dependent or your child who was un­der age 27 at the end of 2014, do not use amounts paid for coverage for that month to fig­ure the deduction. (Pages 20-21).  Sounds like in your case, though, this doesn't apply. (Although your original question doesn't mention a spouse, which might be relevant to the rule if you have one and he/she works.) The publication should help.  If still in doubt, you'll probably need a CPA or other professional to assess your individual situation. "As ApplePie discusses, ""tax bracket"" without any modifiers refers to a single jurisdiction's marginal tax rate.  In your case, this is either your California's ""tax bracket"" or your Federal ""tax bracket"" (not including marginal Social Security and Medicare taxes).  But if someone says ""combined state and federal tax bracket"", they probably mean the combination of your state and federal income tax brackets (again, lot including sales taxes, business and occupational taxes, social security taxes, and medicare taxes).  The math to combine the state and federal marginal tax rates is a bit tricky, because most people can deduct either their state and local income taxes, or their state and local general sales taxes when computing their income for federal income tax purposes.  (The federal ""alternative minimum tax"" restricts this deduction for some people.) For a single person earning $ 100,000 of salaries and wages in California, whose state income taxes are close to their standard deduction, the calculations for the combined marginal income tax rate look something like this: As mentioned above, this understates the tax bite on marginal ""earned income"".  To find the true marginal rate, we need to add in Social Security taxes, Medicare taxes, sales taxes, and business & occupation taxes.  The Social Security and Medicare taxes are sometimes called ""self employment taxes"".  This math omits unemployment insurance and workers' compensation insurance, because those taxes are typically capped well below $ 100,000 per year of income.  This math also omits B & O taxes, because this question is California specific. If an employer wishes to increase an employee's pay by $ 1,076.50, the first $ 76.50 will go to the employer's share of Social Security and Medicare taxes.  The remaining $ 1,000.00 will be subject to the combined marginal income tax rate discussed above, plus will have $ 76.50 go to the employee's share of Social Security and Medicare taxes.  The employee might buy some extra things with some of their extra money, and pay sales tax on them. In 2016, a 9 % sales tax rate was common in California's largest cities. The IRS estimated that (for a single person with no dependents making $ 100,000 per year who did not buy a boat, RV, motor vehicle, or major home construction), about 9 % of their marginal gross income was subject to sales tax." "Yep. You're single, you're possibly still a dependent on your parent's taxes (in lieu of rent), and you're finally bringing home bacon instead of bacon bits. Welcome to the working world. Let's say your gross salary is the U.S. median of $50,000. With bi-weekly checks (26 a year; common practice) you're getting $1923.08 per paycheck. In the 2013 ""Percentage Method"" tax tables, here's how your federal withholding is calculated as a single person paid biweekly: Federal taxes are computed piecewise; the amount up to A is taxed at X%, then the amount between A and B is taxed at Y%, so if you make $C, between A and B, the tax is (A*X) + (C-A)*Y. The amount A*X is included in the ""base amount"" for ease of calculation. Back to our example; let's say you're getting $1923.08 gross wages per check. That puts you in the 25% marginal bracket. You pay the sum of all lesser brackets (which is the ""base amount"" of the 25% bracket), plus the 25% marginal rate on every dollar that falls within the bracket. That's 191.95 + (1923.08 - 1479) * .25 = 191.95 + (444.08 * .25) = 191.95 + 111.02 = $302.97 per paycheck. The ""effective"" tax rate on the total amount, as if you were being charged a flat tax, is 15.75%, and this is just for the federal income tax. Add to this MA state income taxes (5.25% flat tax), FICA (aka Medicare; 1.45% flat) and SECA (aka Social Security; 6.2% up to a ""wage base"" that $50k doesn't even approach), and your effective tax rate on each dollar you earn is 15.75% + 5.25% + 1.45% + 6.2% = 28.65%. This doesn't include any state unemployment taxes that may be withheld separately, but as the rate I come up with is pretty darn close to what you've figured (meaning I slightly overestimated your gross income and thus your effective tax rate), my bet is that SUTA's either employer-paid in MA, or it's just part of MA state income tax. It gets better, at least at the federal level: The amount of your state income taxes is tax-deductible at the federal level if you itemize your deductions. That may not be a factor for you as you'd have to come up with more than $6,100 of other tax-deductible expenses to make itemizing the better option than taking the standard deduction (big-ticket items are mortgage expenses other than principal payments, hospital stays such as for childbirth or major accident, and state and local taxes such as sales, property and income). If you can claim yourself as a dependent (meaning your parents can't), then $150 of each check ($3,900 of your annual salary) is no longer taxed for federal withholding, lowering the amount of money taxed at the 25% marginal rate. You effectively save $37.50 biweekly ($975 annually) in taxes. Get married and file jointly, and your spouse, her personal exemption, and an extra standard deduction amount (if you don't itemize) go on your taxes. The tax rates for married couples filing jointly are also lower; they're currently calculated (or were in 2012) to be the same as if two equal earners were to file separately, so if your spouse doesn't work, your taxes on the single income are calculated at the rates you'd get if you earned half as much. It doesn't work out to half the taxes, but it is a significant ""marriage advantage"". Have kids, and each one is another little $3,900 tax write-off. It's nowhere near the cost of having or raising the child, but it helps, and having kids isn't about the money. Owning a home, making charitable deductions, having medical expenses, etc are a toss-up. The magic number in 2013 is $12,200 for a married couple, $6,100 for a single person. If your mortgage interest, insurance premiums, property taxes, medical expenditures, charitable donations, any contributions from your take-home pay to a tax-deferred savings account (typically these accounts are paid into by your employer as a ""pre-tax deduction"" and never show up as taxable income, but you could just as easily move money from your take-home pay into tax-deferred savings) and any other tax-deductible payments add up to more than 12 large, then itemize. If not, take your standard deduction. As a single taxpayer just starting out in life, you probably don't have any of these types of expenditures, certainly not enough to give up the SD. I did the math on my own taxes in 2012, and was surprised at how little the government actually gets of my paycheck when all's said and done. Remember back in the summer of 2012 when everyone was mad at Romney for making millions and only paying an effective income tax rate of 14%, which was compared to the middle class's marginal rate of 25-28%? Well, my family of 3, living on a little more than the median income from one earner (me), taking the married standard deduction, three personal exemptions, and a little extra for student loan interest, paid an effective federal income tax rate of something like 3.5%. Of course, the FICA and SS taxes don't allow any deductions (not even for retirement savings), so add in the 4.2% SS (in 2012) and 1.45% FICA and the full federal gimme was more like 9-10%." You have interpreted the instructions correctly. The issue with two jobs at the same time, is that that second job will be taxed at the highest rate; but the second employer has no idea what the other position is paying you.  If you make enough to be in the 15% tax bracket for your main job that means: some of the money from each paycheck is  taxed zero; some is taxed at 10% and the last dollars are taxed at 15%. But the second job should withhold for taxes to cover all the income at 15%. To avoid problems you should look at the tax form you are filling out this year. Look at the total tax you paid. Not the refund or the amount you owed when you filed but your total tax paid. The government allows a safe harbor if you make sure that in 2016 you have the same amount withheld this calendar year. If that isn't enough, you will owe money in April 2017, but you will not have to pay a penalty. After you have a couple of paycheck from your main employer, check to see that if you work the rest of the year at that same rate that the federal withholding will make the safe harbor. If you will make it,  you don't have to worry about the penalty. If you will fall short, adjust the w-4 accordingly. "One way to do these sorts of calculations is to use the spreadsheet version of IRS form 1040 available here.  This is provided by a private individual and is not an official IRS tool, but in practice it is usually accurate enough for these purposes.  You may have to spend some time figuring out where to enter the info.  However, if you enter your self-employment income on Schedule C, this spreadsheet will calculate the self-employment tax as well as the income tax.  An advantage is that it is the full 1040, so you can also select the standard deduction and the number of exemptions you are entitled to, enter ordinary W-2 income, even capital gains, etc. Of course you can also make use of other tax software to do this, but in my experience the ""Excel 1040"" is more convenient, as most websites and tax-prep software tend to be structured in a linear fashion and are more cumbersome to update in an ad-hoc way for purposes like tax estimation.  You can do whatever works for you, but I would recommend taking a look at the Excel 1040.  It is a surprisingly useful tool." Then the USA can respond by pulling troops out of these countries and NATO. Think of all the carbon we will save not sending all those planes and tanks and people in other countries. They can spend some of their budgets on protection then, maybe the French can make a green Jet to defend their country.