Taxes and withholding on unpaid salary
As others have said, make sure you can and do file your taxes on a cash basis (not accrual). It sounds like it's very unlikely the company is going to issue you a 1099 for invoices they never paid you. So you just file last year's taxes based on your income, which is the money you actually received. If they do pay you later, in the new year, you'll include that income on next year's tax return, and you would expect a 1099 at that time. Side note: not getting paid is unfortunately common for consultants and contractors. Take the first unpaid invoice and sue them in small claims court. After you win (and collect!), tell them you'll sue them for each unpaid invoice in turn until they pay you in full. (You might need to break up the lawsuits like that to remain under the small claims limit.)
To explain the capital gains part of the question, non qualified stock options (NSOs) are always treated like earned income and have payroll taxes withheld. It's advantageous for the company to issue these because they can deduct them as expenses just as they do your salary. Articles talking about capital gains would probably be referring to incentive stock options (ISOs) or possibly even restricted stock units (RSUs). If you were granted the option to buy the stock and/or hold it for a period of time, then the stock options could be treated as capital gains, short-term gains if you held them for less than a year, and long-term gains if you held them for more than a year. This payment for your NSOs is exactly like a cash bonus. The withholding follows the same guidelines. You may wish to look at what this will mean for your annual salary and adjust your W-4 withholding up or down as appropriate depending on whether the 25% federal withholding rate is more or less than what you think your final marginal rate will be with this bonus included in your annual salary. "The country from which you purchase stock cannot charge you tax on either income or capital gains. Taxation is based on residency, so even when you purchase foreign stock its the tax laws of Malaysia (as your country of residence) that matter. At the time of writing, Malaysia does not levy any capital gains tax and there is no income tax charged on dividends so you won't have to declare or pay any tax on your stocks regardless of where you buy them from. The only exception to this is Dividend Withholding Tax, which is a special tax taken by the government of the country you bought the stock from before it is paid to your account. You do not need to declare this tax as it his already been taken by the time you receive your dividend. The US withholding tax rate on dividends is 30%, although this can be reduced to 15% if there as a tax treaty in place between the US and your country of residence. Malaysia does have a double taxation agreement with the US (see here: http://www.mida.gov.my/env3/index.php?page=double-taxation-agreement) but it is flagged as a ""limited"" agreement.  You'd need to find the full text of the agreement to see whether a reduced rate of dividend withholding tax would be available in the Malaysia/US treaty. See my other answer for more details on withholding taxes and how to partially reclaim under a double tax treaty: What is the dividend tax rate for UK stock Note: Although the taxation rules of both countries are similar, I am a resident of Singapore not Malaysia so I can't speak from first hand experience, but current Malaysia tax rates are easy to find online. The rest of this information is common to any non-US/UK resident investor (as long as you're not a US person)." Unfortunately, the tax system in the U.S. is probably more complicated than it looks to you right now. First, you need to understand that there will be taxes withheld from your paycheck, but the amount that they withhold is simply a guess.  You might pay too much or too little tax during the year.  After the year is over, you'll send in a tax return form that calculates the correct tax amount.  If you have paid too little over the year, you'll have to send in the rest, but if you've paid too much, you'll get a refund.  There are complicated formulas on how much tax the employer withholds from your paycheck, but in general, if you don't have extra income elsewhere that you need to pay tax on, you'll probably be close to breaking even at tax time. When you get your paycheck, the first thing that will be taken off is FICA, also called Social Security, Medicare, or the Payroll tax.  This is a fixed 7.65% that is taken off the gross salary.  It is not refundable and is not affected by any allowances or deductions, and does not come in to play at all on your tax return form. There are optional employee benefits that you might need to pay a portion of if you are going to take advantage of them, such as health insurance or retirement savings.  Some of these deductions are paid with before-tax money, and some are paid with after tax money. The employer will calculate how much money they are supposed to withhold for federal and state taxes (yes, California has an income tax), and the rest is yours. At tax time, the employer will give you a form W-2, which shows you the amount of your gross income after all the before-tax deductions are taken out (which is what you use to calculate your tax).  The form also shows you how much tax you have paid during the year. Form 1040 is the tax return that you use to calculate your correct tax for the year.  You start with the gross income amount from the W-2, and the first thing you do is add in any income that you didn't get a W-2 for (such as interest or investment income) and subtract any deductions that you might have that are not taxable, but were not paid through your paycheck (such as moving expenses, student loan interest, tuition, etc.)  The result is called your adjusted gross income. Next, you take off the deductions not covered in the above section (property tax, home mortgage interest, charitable giving, etc.).  You can either take the standard deduction ($6,300 if you are single), or if you have more deductions in this category than that, you can itemize your deductions and declare the correct amount. After that, you subtract more for exemptions.  You can claim yourself as an exemption unless you are considered a dependent of someone else and they are claiming you as a dependent.  If you claim yourself, you take off another $4,000 from your income. What you are left with is your taxable income for the year.  This is the amount you would use to calculate your tax based on the bracket table you found. California has an income tax, and just like the federal tax, some state taxes will be deducted from your paycheck, and you'll need to fill out a state tax return form after the year is over to calculate the correct state tax and either request a refund or pay the remainder of the tax.  I don't have any experience with the California income tax, but there are details on the rates on this page from the State of California. You should probably talk to a professional tax adviser. This doesn't seem to be a common situation. From the top of my head, without being a lawyer or a tax professional, I think of it like this: The income is for year 200..., and should have been taxed then. You constructively received it then, and not claimed it. You probably had withholding from this salary that should have been reported to you then on W2 (you can get a copy from the IRS). I'd say you're to amend the return for year 200... with the new income, if it wasn't reported then. Although if more than 3 years passed (6, if its 25% or more of your gross income for that year), its beyond statute. However, as I said, I'm not a lawyer and not a professional tax adviser, so you cannot in any way rely on my opinion for anything that would result in not paying any taxes or penalties you should have. You should talk to a licensed tax professional (EA/CPA/Lawyer licensed in your State). "This is a legal issue, or possibly an ethical issue, and not really a finance issue. And I am not a lawyer. But for what it's worth: Did you sign a written contract with H&R Block? If so, then the terms of that contract would govern. If you signed a contract saying that you agree to file your taxes through them if they meet such-and-such conditions, and they met these conditions, then you are legally obligated. If there was no written contract, then I think any court would take the conversation between you and H&R Block as an oral contract. If H&R Block said, basically, ""Okay, we'll calculate what we think your taxes are, and if we come up with something better than what you had before, then you agree to file your taxes through us"", and you said ""Oh, okay"", then that's an oral contract. You agreed to their conditions. Legally, oral contracts are just as binding as written contracts. The only difference is that it is difficult to prove exactly what was said. If you really did agree to these conditions, I suppose you could lie and say you didn't and then try to convince a court that they are the ones lying. Obvious ethical problems there. There are also implied contracts. If HRB's advertising or paperwork says that you're agreeing to file through them if they meet the conditions, I thing that a court would likely rule that you implicitly agreed to their terms by doing the review. In any case, when you go to some place like HRB mostly what you are paying for is their knowledge and expertise. So if they give you the benefit of their expertise -- they tell you how to reduce your taxes -- and then you don't pay them, that seems rather unethical to me. The situation is muddied by the fact that you paid $100 for the review. Is that paying for the basic information, the ""tax tip"", and paying for them to file is then a contract for additional work? Under some circumstances I'd say yes, that's additional work and thus an additional contract, so in the absence of a contract obligating me, I don't have to do that. The catch in this case is that at that point they must have already pretty much taken all your information and filled out all the forms. All that's left is to press the ""send"" button and submit the return, right?" To clarify that legality of this (for those that question it), this is directly from IRS Publication 926 (2014) (for household employees): If you prefer to pay your employee's social security and Medicare taxes from your own funds, do not withhold them from your employee's wages. The social security and Medicare taxes you pay to cover your employee's share must be included in the employee's wages for income tax purposes. However, they are not counted as social security and Medicare wages or as federal unemployment (FUTA) wages. I am sorry this does not answer your question entirely, but it does verify that you can do this. UPDATE:  I have finally found a direct answer to your question!  I found it here: http://www.irs.gov/instructions/i1040sh/ar01.html Form W-2 and Form W-3 If you file one or more Forms W-2, you must also file Form W-3. You must report both cash and noncash wages in box 1, as well as tips and other compensation. The completed Forms W-2 and W-3 in the example (in these instructions) show how the entries are made. For detailed information on preparing these forms, see the General Instructions for Forms W-2 and W-3. Employee's portion of taxes paid by employer.    If you paid all of your employee's share of social security and Medicare taxes, without deducting the amounts from the employee's pay, the employee's wages are increased by the amount of that tax for income tax withholding purposes. Follow steps 1 through 3 below. (See the example in these instructions.) Enter the amounts you paid on your employee's behalf in boxes 4 and 6 (do not include your share of these taxes). Add the amounts in boxes 3, 4, and 6. (However, if box 5 is greater than box 3, then add the amounts in boxes 4, 5, and 6.) Enter the total in box 1. "If you're making $80k, and you're consulting for an extra $400/wk or $20,800/yr, you're earning a total of $100,800.  That's assuming you do it for a full calendar year of course.  Either way, assuming you can deduct/exclude at least $11k of income (as almost everyone can), you're paying 25% on your marginal dollars.  (This also assumes you're single; if you're married/filing jointly, this may not be true.)  Note, you're right at the edge of the 25% bracket if you earn this in a full calendar year - but if you have a 401k, health insurance, or other reductions you'll be fine.  Additionally, for this year you'll be under (again assuming single and no other income) because you aren't earning a full year's worth. Assuming your $80k is precisely taken care of by your regular withholding, then, you will literally pay 25%*$400/week in additional taxes - $100 per week.  So if you are paid biweekly, you need to add $200/week in withholding on your W-4.  If you expect to overpay taxes (if you own a house with a mortgage for example, you often do), you can reduce it some, but adding $200/biweekly paycheck should bring you right to where you were before the extra income. The general rule is to calculate your marginal (not effective) tax rate before the new income, assuming default withholding takes care of that, and then withhold the marginal rate for the new income [checking that the new income doesn't push the marginal rate up - if so, calculate in two parts, the part in the lower marginal rate and the part in the higher marginal rate]. You can google ""2014 tax brackets"", or look at the IRS tax tables for detailed information about marginal rates." Yes, you can send in a 2012 1040-ES form with a check to cover your tax liability. However, you will likely have to pay penalties for not paying tax in timely fashion as well as interest on the late payment. You can have the IRS figure the penalty and bill you for it, or you can complete Form 2210 (on which these  matters are figured out) yourself and file it with your Form 1040. The long version of Form 2210 often results in the smallest extra amount due but is considerably more time-consuming to complete correctly. Alternatively, if you or your wife have one or more paychecks coming before the end of 2012, it might be possible to file a new W-4 form with the HR Department with a request to withhold additional amounts as Federal income tax. I say might because if the last paycheck of the year will be issued in just a few days' time, it might already have been sent for processing, and HR might tell you it is too late. But, depending on the take-home pay, it might be possible to have the entire $2000 withheld as additional income tax instead of sending in a 1040-ES. The advantage of doing it through withholding is that you are allowed to treat the entire withholding for 2012 as satisfying the timely filing requirements. So, no penalty for late payment even though you had a much bigger chunk withheld in December, and no interest due either.  If you do use this approach, remember that Form W-4 applies until it is replaced with another, and so  HR will continue to withhold the extra amount on your January paychecks as well.  So, file a new W-4 in January to get back to normal withholding. (Fix the extra exemption too so the problem does not recur in 2013).