Paying estimated taxes in a quarter with losses
Yes, if you're caught up you can skip the quarter.
You are not allowed to pick and choose what years to take a loss once the stock/fund is sold.  While I realize it might be too late for you to do anything now, in the future if members should read this, they might consider doing a Roth conversion during that year they will have $3000 in losses. This way they will show some income that can be offset by that loss, effectively getting a free conversion to the Roth. In general, you are expected to pay all the money you owe in taxes by the end of the tax year, or you may have to pay a penalty. But you don't have to pay a penalty if: The amount you owe (i.e. total tax due minus what you paid in withholding and estimated taxes) is less than $1000. You paid at least 90% of your total tax bill. You paid at least 100% of last year's tax bill. https://www.irs.gov/taxtopics/tc306.html I think point #3 may work for you here. Suppose that last year your total tax liability was, say, $5,000. This year your tax on your regular income would be $5,500, but you have this additional capital gain that brings your total tax to $6,500. If your withholding was $5,000 -- the amount you owed last year -- than you'll owe the difference, $1,500, but you won't have to pay any penalties. If you normally get a refund every year, even a small one, then you should be fine. I'd check the numbers to be sure, of course. If you normally have to pay something every April 15, or if your income and therefore your withholding went down this year for whatever reason, then you should make an estimated payment. The IRS has a page explaining the rules in more detail: https://www.irs.gov/help-resources/tools-faqs/faqs-for-individuals/frequently-asked-tax-questions-answers/estimated-tax/large-gains-lump-sum-distributions-etc/large-gains-lump-sum-distributions-etc My understanding is that losses are first deductible against any capital gains you may have, then against your regular income (up to $3,000 per year).  If you still have a loss after that, the loss may be carried over to offset capital gains or income in subsequent years As you suspect, a short term capital loss is deductible against short term capital gains and long term losses are deductible against long term gains.  So taking the loss now MIGHT be beneficial from a tax perspective.  I say MIGHT because there are a couple scenarios in which it either may not matter, or actually be detrimental: If you don't have any short term capital gains this year, but you have long term capital gains, you would have to use the short term loss to offset the long term gain before you could apply it to ordinary income.  So in that situation you lose out on the difference between the long term tax rate (15%) and your ordinary income rate (potentially higher). If you keep the stock, and sell it for a long term loss next year, but you only have short-term capital gains or no capital gains next year, then you may use the long term loss to offset your short-term gains (first) or your ordinary income.   Clear as mud? The whole mess is outlined in IRS Publication 550 Finally, if you still think the stock is good, but just want to take the tax loss, you can sell the stock now (to realize the loss) then re-buy it in 30 days.  This is called Tax Loss Harvesting.  The 30 day delay is an IRS requirement for being allowed to realize the loss. I suspect that the payments were originally due near the end of each quarter (March 15, June 15, September 15, and December 15) but then the December payment was extended to January 15 to allow for end-of-year totals to be calculated, and then the March payment was extended to April 15 to coincide with Income Tax Return filing. The estimated approach puts more burden on you to get it right.  Depending on when in the year you make the sale, it may or may not have advantages to you in addition.  Other than the responsibility of ensuring that you make the payment on time, the pros and cons seem to be: Either strategy is legitimate.  It depends on when in the year you have the sale, how sure you are of the sale, and just your personal preference on how to get this done.  Your total tax due for the year will not be different (as long as you pay in such as way that you don't incur late penalties in any quarter). If so, are there ways to reduce the amount of taxes owed? Given that it's currently December, I suppose I could sell half of what I want now, and the other half in January and it would split the tax burden over 2 years instead, but beyond that, are there any strategies for tax reduction in this scenario? One possibility is to also sell stocks that have gone down since you bought them.  Of course, you would only do this if you have changed your mind about the stock's prospects since you bought it -- that is, it has gone down and you no longer think it will go up enough to be worth holding it.  When you sell stocks, any losses you take can offset any gains, so if you sell one stock for a gain of $10,000 and another for a loss of $5,000, you will only be taxed on your net gain of $5,000. Even if you think your down stock could go back up, you could sell it to realize the loss, and then buy it back later at the lower price (as long as you're not worried it will go up in the meantime).  However, you need to wait at least 30 days before rebuying the stock to avoid wash sale rules.  This practice is known as tax loss harvesting. Wanna make sure every company pays at least some taxes? Install a 'tax floor'. Basically, no matter how many losses you claim, no matter how much you offshore, no matter how many loopholes you find, you can not drop below a certain number. Let's say 15%. That is it, you have to pay at least 15%.   As this takes effect, and only after revenues stream in for a few years to help balance things out, you can even slightly adjust the high rate down a tad to help the big companies that don't use the loopholes.  Please spread this idea around. Estimated tax payments should be a reasonable estimate of what you owe for that time period. If it seems reasonable to you, it is probably reasonable. Sure, you can adjust for varying-length periods. As long as, in the end, you can and do pay what you owe, and don't underpay the estimated/withholding by enough that you owe a penalty, the IRS isn't all that picky about how the money is actually distributed through the year. The loss for B can be used to write off the gain for A.  You will fill out a schedule 3 with cost base and proceeds of disposition.  This will give you a $0 capital gain for the year and an amount of $5 (50% of the $10 loss) you can carry forward to offset future capital gains.  You can also file a T1-a and carry the losses back up to 3 years if you're so inclined.  It can't be used to offset other income (unless you die). Your C and D trades can't be on income account except for very unusual circumstances.  It's not generally acceptable to the CRA for you to use 2 separate accounting methods.  There are some intricacies but you should probably just use capital gains.   There is one caveat that if you do short sales of Canadian listed securities, they will be on income account unless you fill out form T-123 and elect to have them all treated as capital gains. I just remembered one wrinkle in carrying forward capital losses.  They don't reduce your capital gains anymore, but they reduce your taxable income.  This means your net income won't be reduced and any benefits that are calculated from that (line 236), will not get an increase. They pay nearly $900 million per year in income taxes. Their effective rate is low because they have deferred tax assets, which means they paid more in taxes years prior in order to get a lower effective rate now. Additionally, they have a net loss carryforward, which allows a business to reduce their tax burden two years prior or up to 20 years forward after losing money. If you owe a lot of money (more then $500 or $1000) you will get hit with penalties. You will also have to file every quarter the next year. That is very painful. There is a safe harbor if you make sure that you have withheld more money than your taxes from the previous year. The information you provided is not enough for me to give specific advice. But here is a hint: Right after you file this year, use turbo tax to determine what changes you can make to your withholding to minimize any excess withholding. "You have a sequence of questions here, so a sequence of answers: If you stopped at the point where you had multiple wins with a net profit of $72, then you would pay regular income tax on that $72. It's a short term capital gain, which does not get special tax treatment, and the fact that you made it on multiple transactions does not matter. When you enter your next transaction that takes the hypothetical loss the question gets more complicated. In either case, you are paying a percentage on net gains.  If you took a two year view in the second case and you don't have anything to offset your loss in the second year, then I guess you could say that you paid more tax than you won in the total sequence of trades over the two years. Although you picked a sequence of trades where it does not appear to play, if you're going to pursue this type of strategy then you are likely at some point to run into a case where the ""wash sale"" rules apply, so you should be aware of that.  You can find information on this elsewhere on this site and also, for example, here: http://www.marketwatch.com/story/understanding-the-wash-sale-rules-2015-03-02  Basically these rules require you to defer recording a loss under some circumstances where you have rapid wins and losses on ""substantially identical"" securities. EDIT A slight correction, you can take part of your losses in the second year even if you have no off-setting gain.  From the IRS: If your capital losses exceed your capital gains, the amount of the excess loss that you can claim on line 13 of Form 1040 to lower your income is the lesser of $3,000, ($1,500 if you are married filing separately)" The harvested losses are capital losses.  See this IRS page: Generally, realized capital losses are first offset against realized capital gains.  Any excess losses can be deducted against ordinary income up to $3,000 ($1,500 if married filing separately) on line 13 of Form 1040.  Losses in excess of this limit can be carried forward to later years to reduce capital gains or ordinary income until the balance of these losses is used up. This means that your harvested losses can be used to offset ordinary income --- up to $3000 in a single year, and with extra losses carried forward to future years.  It is pretty close to a free lunch, provided that you have some losses somewhere in your portfolio. This free lunch is available to anyone, but for a human, it can be quite a chore to decide when to sell what, keep track of the losses, and avoid the wash sale rules.  The advantage of robo-advisors is that they eat that kind of bookkeeping for breakfast, so they can take advantage of tax loss harvesting opportunities that would be too cumbersome for a human to bother with. E.g. I buy 1 stock unit for $100.00 and sell it later for $150.00 => income taxes arise. Correct. You pay tax on your gains, i.e.: the different between net proceeds and gross costs (proceeds sans fees, acquisition costs including fees). I buy 1 stock unit for $150.00 and sell it later for $100.00 => no income taxes here. Not correct. The loss is deductible from other capital gains, and if no other capital gains - from your income (up to $3000 a year, until exhausted). Also, there are two different tax rate sets for capital gains: short term (holding up to 1 year) and long term (more than that). Short term capital gains tax matches ordinary income brackets, whereas long term capital gains tax brackets are much lower. "The heart of the question is: why can't Bill just pay whatever he owes based on his income in that quarter? If Q2 is gang busters, he'll increase his tax payment. Then if Q3 is surprisingly slow, he'll pay less than he paid in Q2. I think what's most interesting about this question is that the other answers are geared towards how a taxpayer is supposed to estimate taxes. But that's not my objective -- nor is it Bill's objective. My [his] real objective is:  In other words, the answer to this question either needs to deal with not overpaying, or it needs to deal with mitigating the underpayment penalty. AFAICT, there are 2 solutions: Solution 1 Figure your estimated taxes based on last year's tax. You won't owe a penalty if your withholding + estimated tax payments in each quarter are 25% or more of your previous year's tax liability. Here's the section that I am basing this on: http://www.irs.gov/publications/p505/ch04.html Minimum required each period.   You will owe a penalty for any 2011 payment period for which your estimated tax payment plus your withholding for the period and overpayments for previous periods was less than the smaller of: 22.5% of your 2011 tax, or 25% of your 2010 tax. (Your 2010 tax return must cover a 12-month period.) Solution 2 Use the ""Annualized Income Installment Method"". This is not a method for calculating estimated taxes, per se. It's actually a method for reducing or eliminating your underpayment penalty. It's also intended to assist tax payers with unpredictable incomes. If you did not receive your income evenly throughout the year (for example, your income from a shop you operated at a marina was much larger in the summer than it was during the rest of the year), you may be able to lower or eliminate your penalty by figuring your underpayment using the annualized income installment method. Emphasis added. In order to take advantage of this, you'll need to send in a Schedule AI at the end of the year along with a Form 2210. The downside to this is that you're basically racking up underpayment penalties throughout the year, then at the end of the year you're asking the IRS to rescind your penalty. The other risk is that you still pay estimated taxes on your Q2 - Q4 earnings in Q1, you just pay much less than 25%. So if you have a windfall later in the year, I think you could get burned on your Q1 underpayment."