Which tax year does a bonus fall under?
From HMRC Note that the rule is when a person becomes entitled to payment of earnings. This is not necessarily the same as the date on which an employee acquires a right to be paid. For example, an employee's terms of service may provide for the employee to receive a bonus for the year to 31 December 2004, payable on 30 June 2005 if the employee is still in the service of the employer on 31 December 2004. If the condition is satisfied the employee becomes entitled to a payment on 31 December 2004 but is only entitled to payment of it on 30 June 2005. So PAYE applies to it on 30 June 2005 and it is assessable for 2005/06. The date that matters is the date the employee is entitled to be paid the bonus.  But why are you worried about paying tax. That is your employer's responsibility and they will do it for you. Ask you firm's finance department also for further clarification. HMRC are not an organization to mess with, they will tie up your life in knots.
"Assuming U.S. law, there are ""safe harbor"" provisions for exactly this kind of situation. There are several possibilities, but the most likely one is that if your withholding and estimated tax payments for 2016 totaled at least as much as your tax bill for 2015 there's no penalty. For the full rules, see IRS Publication 17." I think the IRS doc you want is http://www.irs.gov/publications/p550/ch04.html#en_US_2010_publink100010601 I believe the answers are: "Your real question, ""why is this not discussed more?"" is intriguing. I think the media are doing a better job bringing these things into the topics they like to ponder, just not enough, yet.  You actually produced the answer to How are long-term capital gains taxed if the gain pushes income into a new tax bracket? so you understand how it works.  I am a fan of bracket topping. e.g. A young couple should try to top off their 15% bracket by staying with Roth but then using pretax IRA/401(k) to not creep into 25% bracket.  For this discussion, 2013 numbers, a blank return (i.e. no schedule A, no other income) shows a couple with a gross $92,500 being at the 15%/25% line. It happens that $20K is exactly the sum of their standard deduction, and 2 exemptions.  The last clean Distribution of Income Data is from 2006, but since wages haven't exploded and inflation has been low, it's fair to say that from the $92,000 representing the top 20% of earners, it won't have many more than top 25% today. So, yes, this is a great opportunity for most people.  Any married couple with under that $92,500 figure can use this strategy to exploit your observation, and step up their basis each year. To littleadv objection - I imagine an older couple grossing $75K, by selling stock with $10K in LT gains just getting rid of the potential 15% bill at retirement. No trading cost if a mutual fund, just $20 or so if stocks.  The more important point, not yet mentioned - even in a low cost 401(k), a lifetime of savings results in all gains being turned in ordinary income. And the case is strong for 'deposit to the match but no no more' as this strategy would let 2/3 of us pay zero on those gains.  (To try to address the rest of your questions a bit - the strategy applies to a small sliver of people. 25% have income too high, the bottom 50% or so, have virtually no savings. Much of the 25% that remain have savings in tax sheltered accounts. With the 2013 401(k) limit of $17,500, a 40 year old couple can save $35,000. This easily suck in most of one's long term retirement savings. We can discuss demographics all day, but I think this addresses your question.) If you add any comments, I'll probably address them via edits, avoiding a long dialog below." "Your question does not say this explicitly, but I assume that you were once a W-2 employee.  Each paycheck a certain amount was withheld from your check to pay income, social security, and medicare taxes.  Just because you did not receive that amount of money earned does not mean it was immediately sent to the IRS.  While I am not all that savvy on payroll procedures, I recall an article that indicated some companies only send in withheld taxes every quarter, much like you are doing now.  They get a short term interest free loan.  For example taxes withheld by a w-2 employee in the later months of the year may not be provided to the IRS until 15 January of the next year.   You are correct in assuming that if you make 100K as a W-2 you will probably pay less in taxes than someone who is 100K self employed with 5K in expenses.  However there are many factors.  Provided you properly fill out a 1040ES, and pay the correct amount of quarterly payments, you will almost never owe taxes.  In fact my experience has been the forms will probably allow you to receive a refund.  Tax laws can change and one thing the form did not include last year was the .9% Medicare surcharge for high income earners catching some by surprise.    As far as what you pay into is indicative of the games the politicians play.  It all just goes into a big old bucket of money, and more is spent by congress than what is in the bucket.  The notion of a ""social security lockbox"" is pure politics/fantasy as well as the notion of medicare and social security taxes.  The latter were created to make the actual income tax rate more palatable.     I'd recommend getting your taxes done as early as possible come 1 January 2017.  While you may not have all the needed info, you could firm up an estimate by 15 Jan and modify the amount for your last estimated payment.  Complete the taxes when all stuff comes in and even if you owe an amount you have time to save for anything additional.  Keep in mind, between 1 Jan 17 and 15 Apr 17 you will earn and presumably save money to use towards taxes.  You can always ""rob"" from that money to pay any owed tax for 2016 and make it up later. All that is to say you will be golden because you are showing concern and planning.  When you hear horror stories of IRS dealings it is most often that people spent the money that should have been sent to the IRS." If you had a retirement plan at any time in 2013 you are considered covered by an plan. Are You Covered by an Employer's Retirement Plan? You’re covered by an employer retirement plan for a tax year if your   employer (or your spouse’s employer) has a: Defined contribution plan (profit-sharing, 401(k), stock bonus and money purchase pension plan) and any contributions or forfeitures were   allocated to your account for the plan year ending with or within the   tax year; IRA-based plan (SEP, SARSEP or SIMPLE IRA plan) and you had an amount contributed to your IRA for the plan year that ends with or   within the tax year; or Defined benefit plan (pension plan that pays a retirement benefit spelled out in the plan) and you are eligible to participate for the   plan year ending with or within the tax year. Box 13 on the Form W-2 you receive from your employer should contain a   check in the “Retirement plan” box if you are covered. If you are   still not certain, check with your (or your spouse’s) employer. The limits on the amount you can deduct don’t affect the amount you   can contribute. However, you can never deduct more than you actually   contribute. Additional Resources: Publication 590, Individual Retirement Arrangements (IRAs) There is one edge case that may be of value to you. If you declare a bonus (probably to yourself given a very small company) you can deduct it from your year and then have up to 6 months to actually write the cheque and give it to the person. Say your year end for the corporation is July 31st. You could declare the bonus July 30th and deduct it from that year, lowering your corporate tax. You could then wait until January 30th to actually write the bonus cheque. The person would then have that taxable income in a later calendar year, deferring paying the tax. Depending on the size of the bonus, this would possibly matter, although if you did large bonuses every year it would only matter the first time. The other issue is the availability of your bookkeeper or accountant. They are sometimes very busy during personal income tax season. They often like a vacation immediately after that. They may go away in the summer when their kids are out of school. The nice thing about a July 31st year end is that you can probably count on a quick turnaround from your accountant in September. The possible downside is that you won't enjoy reconciling your credit card statements and the like in August as part of getting your year end stuff together. You can avoid that by keeping your books in a decent shape all the time. Form 1099-misc reports PAYMENTS, not earnings.  This does not imply the EARNINGS are not taxable in the year they were earned. In addition to the prior answer, talking from experience, you get into trouble if you surpass the contribution limit and your employer continues to deposit money above the IRS maximum allowed. When that happens, you have until April to take out the excess contribution and earned interest on that chunk of money and included in your tax return or else you get a steep tax penalty in addition to being double taxed ( for the current and next tax year). Also from experience, payroll departments will most likely get this wrong and it will end up in a compliance mess with you picking up the tab on your tax bill. Don't let it happen!!! The IRA contribution for the year are allowed until the tax day of that year. I.e.: you can contribute for 2015 until April 15th, 2016 (or whatever the first business day is after that, if the 15th is a holiday). You'll have to explicitly designate your contribution for 2015, since some of the IRA providers may automatically designate the current year unless you explicitly say otherwise. If that happens - it will be very hard to fix later, so pay attention when you're making the contribution. You get a couple of things from your IRA provider: Form 5498 - details your contributions for the year, account FMV, and RMD details. You can see the actual form here. You don't always get this form, if you didn't contribute anything and no RMD is required for you. Since the last day to contribute is April 15th, these forms are usually being sent out around mid-May. But you should know how much you've contributed by the tax day without it, obviously, so this is only for the IRS matching and your record-tracking.  Form 1099-R includes information about distributions (including withdrawals and roll-overs). You may not get this form if you didn't take any money out of your IRA. These come out around end of January. I don't believe there exists a tax-advantage for paying employees a bonus instead of increased salary. It's all expense to the employer, it's all income to you, and it's taxed the same (bonus checks might have more withheld, but your end of year tax burden doesn't change). It does benefit your employer to delay a significant portion of your pay until the end of the year, delaying payment provides buffer in case of delays in getting paid by the client. Your employer could even put the extra money to work earning more money over the year.  It would depend on your contract, but are you due your bonus if you were to leave your job before year-end? If not, that's a great reason to delay payment, because it makes you less likely to leave mid-year, and should you not work out they can keep the difference. "Yes, the penalty is the tax you pay on it again when you withdraw the money. The withdrawal of the excess contribution is taxed as your wages (but no penalty). Excess contribution cannot be added to the basis or considered ""after-tax"" (hence the double taxation). Note that allowing you to keep the excess contribution in the plan may lead to disqualifying the plan, so it is likely that the plan administrator will force you to remove the excess contribution if they become aware of it. Otherwise you may end up forcing early 401(k) withdrawal on all of your co-workers. More on this IRS web page. And this one." Contributions are post-tax, so there's no direct tax benefit to choosing a year. I just made a 2010 contribution today, and the institution's form explicitly asks me if I want it on 2010 or 2011.  The primary advantage of backdating like this is being able to contribute 5k more over your lifetime than otherwise possible, under the timing constraints. While there may be a year in the future which you don't contribute the max, contributing now lets you build up earnings tax free. For '10 vs '11, you're probably holding cash so it's not a big deal, but over five years is a long time to hold cash or invest with tax penalty. "In a Traditional IRA contributions are often tax-deductible. For instance, if a taxpayer contributes $4,000 to a traditional IRA and is in the twenty-five percent marginal tax bracket, then a $1,000 benefit ($1,000 reduced tax liability) will be realized for the year. So that's why they tax you as income, because they didn't tax that income before. If a taxpayer expects to be in a lower tax bracket in retirement than during the working years, then this is one advantage for using a Traditional IRA vs a Roth. Distributions are taxed as ordinary income. So it depends on your tax bracket  UPDATE FOR COMMENT: Currently you may have heard on the news about ""the fiscal cliff"" - CNBC at the end of the year. This is due to the fact that the Bush tax-cuts are set to expire and if they expire. Many tax rates will change. But here is the info as of right now: Dividends: From 2003 to 2007, qualified dividends were taxed at 15% or 5% depending on the individual's ordinary income tax bracket, and from 2008 to 2012, the tax rate on qualified dividends was reduced to 0% for taxpayers in the 10% and 15% ordinary income tax brackets. After 2012, dividends will be taxed at the taxpayer's ordinary income tax rate, regardless of his or her tax bracket. - If the Bush tax cuts are allowed to expire. - Reference - Wikipedia Capital Gains tax rates can be seen here - the Capital Gains tax rate is relative to your Ordinary Income tax rate For Example: this year long term gains will be 0% if you fall in the 15% ordinary tax bracket. NOTE: These rates can change every year so any future rates might be different from the current year." It's legal. In fact, they are required to do this, assuming you are in fact a HCE (highly compensated employee) to avoid getting in trouble with the IRS. I'm guessing they don't provide documentation for the same reason they don't explain to you explicitly what the income thresholds are for social security taxes, etc - that's a job for your personal accountant. Here's the definition of a HCE:  An individual who: Owned more than 5% of the interest in the business at any time during   the year or the preceding year, regardless of how much compensation   that person earned or received, or For the preceding year, received   compensation from the business of more than $115,000 (if the preceding   year is 2014; $120,000 if the preceding year is 2015, 2016 or 2017),   and, if the employer so chooses, was in the top 20% of employees when   ranked by compensation. There are rules the restrict distributions from plans like 401ks. For example, treasury reg 1.401a(4)-5(b)(3) says that a plan cannot make a distribution to a HCE if that payment reduces the asset value of the plan to below 110% of the value of the plan's current liabilities. So, after taking account all distributions to be made to HCEs and the asset value of the plan, everyone likely gets proportionally reduced so that they don't run afoul of this rule. There are workarounds for this. But, these are options that the plan administrators may take, not you. I suppose if you were still employed there and at a high enough level, a company accountant would have discussed these options with you. Note, there's a chance there's some other limitation on HCEs that I'm missing which applies to your specific situation. Your best bet, to understand, is simply ask. Your money is still there, you just can't get it all this year. Overcontributions made after the calendar year are not usually a problem. This is because while contributions made in Jan and Feb can be counted towards the previous year, they do not have to be. This appears to be what has happened in your case. If you had an RRSP limit of $18,000 for 2015, and in Jan 2016 you contributed $22,000 to your RRSP, then it is perfectly legal to claim $18,000 of that in 2015 and $4000 in 2016. The extra $4000 is never counted against your 2015 limit and so is not an overcontribution. If your 2016 limit is going to be less than $4000 then you will eventually have an overcontribution problem in 2016, and if you think that's likely you should sort this out now. But for most people that's pretty unlikely.