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.
The Motley Fool article is correct that if you earn UBTI over $1000, you will need to pay the tax, even if held in an IRA.   C-corps won't generate UBTI, so you're fine with those.  For non-C-corps, the most common are REITs, MLPs, and BDCs.   REITs  These typically invest in either real estate property or mortgages.  The ones that invest in mortgages are sometimes notated: mREITs, and can occasionally generate UBTI.  Tip: Don't let this stop you from investing in REITs in your IRA.  REITs can be a great source of income and are best held in an IRA since the income will be tax free vs. your ordinary income tax bracket if held in a taxable account.  Some examples of mREITs would be NLY, CIM, AGNC.  Some property REITs would be: O, SNR, OHI, EQR. https://seekingalpha.com/article/1257351-tax-bomb-mortgage-reits-triggering-ubit MLPs Master Limited Partnerships are also pass-through entities, like REITs, but have the additional complication that most issue K-1 forms at tax time.  K-1s can be very complex when the MLP owns assets across state boundaries, which is why I actually PREFER to hold MLPs in my IRA (against the advice of M. Fool) since I won't have to deal with the tax complications of filing the K-1, just as long as my MLPs don't generate over $1000 of UBTI. https://seekingalpha.com/article/4057891-mlps-kminus-1s-ubti-oh BDCs Business Development Companies like REITs and MLPs are also pass-through entities in that the income they give you will be taxed at your ordinary income bracket if held in a taxable account.  Examples of BDCs include: MAIN, MCC, ARCC.  You'd need to consult their 10-K to determine if there is a risk of UBTI. Tip:  MLPs, BDCs, and especially REITs can all be very valuable sources of income and from my experience, UBTI is rare so don't let that scare you away if you otherwise like the investment. If you're waiting for Apple to send you a 1099 for the 2008 tax season, well, you shouldn't be. App Store payments are not reported to the IRS and you will not be receiving a 1099 in the mail from anyone. App Store payments are treated as sales commissions rather than royalties, according to the iTunes Royalty department of Apple. You are responsible for reporting your earnings and filing your own payments for any sums you have earned from App Store.   – https://arstechnica.com/apple/2009/01/app-store-lessons-taxes-and-app-store-earnings The closest thing to sales commissions in WA state seems to be Service and Other Activities described at  http://dor.wa.gov/content/FileAndPayTaxes/BeforeIFile/Def_TxClassBandO.aspx#0004. When you dig a little deeper into the tax code, WAC 458-20-224 (Service and other business activities) includes: (4) Persons engaged in any business activity, other than or in addition to those for which a specific rate is provided in chapter 82.04 RCW, are taxable under the service and other business activities classification upon gross income from such business.   - http://apps.leg.wa.gov/wac/default.aspx?cite=458-20-224 I am not a lawyer or accountant, so caveat emptor. You only pay tax on the capital gain of the bond, not the principal, unless the source of the money for the principal was gain from another investment, if that makes sense.   In other words, if you bought the bond with income earned from your job, that money was already taxed as income, so it isn't subject to taxation again when you redeem the bond.  On the other hand, if you cashed out of one investment and used those proceeds to buy a bond, then the entire amount might be taxable. The fact that this is what’s being reported is horribly misleading.  At the bottom of the same page of that report, there is data intended to show the difference between the pay rates in genders. This data accidently proves that individual incomes are still stagnant and that the reason for our increased household wages is that more people per household are working, and part timers are working longer hours. Following is how this conclusion is drawn:  The section titled “Earnings of Full Time, Year-Round Workers,” can be used to find 2015’s average income per full time worker, and 2016’s average income per full time worker. The 2015 data shows that men made up 57.51% of the full time, year round working population (63,887/111,098) and earned $51,859.00. Women made up 42.49% of the full time, year round working population (47,211/111,098) and earned $41,257.00. This means that the average income for a full time, year round worker in 2015 was $47,353.69 (51,859 x .5751 + 41,257 x .4249).  The 2016 data shows that men made up 57.34% of the full time, year round working population (64,953/113,281) and earned $51,640.00. Women made up 42.66% of the population (48,328/113,281) and earned $41,554.00. This means the average income for a full time, year round worker in 2016 was $47,337.11 (51,640 x .5734 + 41,554 x .4266).  So while the news is reporting the increase in household income, the average income for a full time, year round worker actually fell by $16.58 in 2016. You need to report the income from any work as income, regardless of if you invest it, spend it, or put it in your mattress (ignoring tax advantaged accounts like 401ks).  You then also need to report any realized gains or losses from non-tax advantaged accounts, as well as any dividends received.  Gains and losses are realized when you actually sell, and is the difference between the price you bought for, and the price you sold for.  Gains are taxed at the capital gains rate, either short-term or long-term depending on how long you owned the stock.   The tax system is complex, and these are just the general rules.  There are lots of complications and special situations, some things are different depending on how much you make, etc.  The IRS has all of the forms and rules online.  You might also consider having a professional do you taxes the first time, just to ensure that they are done correctly.  You can then use that as an example in future years. Just from my own experience (I am not an accountant): In addition to counting as 'business income' (1040 line 12 [1]) your $3000 (or whatever) will be subject to ~15% self-employment tax, on Schedule SE.  This carries to your 1040 line ~57, which is after all your 'adjustments to income', exemptions, and deductions - so, those don't reduce it.  Half of the 15% is deductible on line ~27, if you have enough taxable income for it to matter; but, in any case, you will owe at least 1/2 of the 15%, on top of your regular income tax. Your husband could deduct this payment as a business expense on Schedule C; but, if (AIUI) he will have a loss already, he'll get no benefit from this in the current year.   If you do count this as income to you, it will be FICA income; so, it will be credited to your Social Security account. Things outside my experience that might bear looking into:  I suspect the IRS has criteria to determine whether spousal payments are legit, or just gaming the tax system.  Even if your husband can't 'use' the loss this year, he may be able to apply it in the future, when/if he has net business income. [1] NB: Any tax form line numbers are as of the last I looked - they may be off by one or two. It actually depends on the services provided. If you're renting through AirBnB, you're likely to provide much more services to the tenants than a traditional rental. It may raise it to a level when it is no longer a passive activity. See here, for starters: Providing substantial services.   If you provide substantial services   that are primarily for your tenant's convenience, such as regular   cleaning, changing linen, or maid service, you report your rental   income and expenses on Schedule C (Form 1040), Profit or Loss From   Business, or Schedule C-EZ (Form 1040), Net Profit From Business. Use   Form 1065, U.S. Return of Partnership Income, if your rental activity   is a partnership (including a partnership with your spouse unless it   is a qualified joint venture). Substantial services do not include the   furnishing of heat and light, cleaning of public areas, trash   collection, etc. For information, see Publication 334, Tax Guide for   Small Business. Also, you may have to pay self-employment tax on your   rental income using Schedule SE (Form 1040), Self-Employment Tax. For   a discussion of “substantial services,” see Real Estate Rents in   Publication 334, chapter 5 "What theyre fishing for is whether the money was earned in the U.S.  It's essentially an interest shelter, and/or avoiding double taxation.   They're saying if you keep income you make outside the US in a bank inside the US, the US thanks you for storing your foreign money here and doesn't tax the interest (but the nation where you earned that income might).   There is no question that the AirBNB income is ""connected with a US trade or business"".   So your next question is whether the fraction of interest earned from that income can be broken out, or whether IRS requires you to declare all the interest from that account.   Honestly given the amount of tax at stake, it may not be worth your time researching.   Now since you seem to be a resident nonresident alien, it seems apparent that whatever economic value you are creating to earn your salary, is being performed in the United States. If this is for an American company and wages paid in USD, no question, that's a US trade or business. But what if it's for a Swedish company running on Swedish servers, serving Swedes and paid in Kroner to a Swedish bank which you then transfer to your US bank? Does it matter if your boots are on sovereign US soil?  This is a complex question, and some countries (UK) say ""if your boots are in our nation, it is trade/income in our nation""... Others (CA) do not.  This is probably a separate question to search or ask. To be clear, the fact that your days as a teacher or trainee do not count toward residency, is a separate question from whether your salary as same counts as US income."