Sales Tax: Rounded Then Totaled or Totaled Then Rounded?
"Tax is often calculated per item.  Especially in the days of the internet, some items are taxable and some aren't, depending on the item and your nexus.  I would recommend calculating and storing tax with each item, to account for these subtle differences. EDIT: Not sure why this was downvoted, if you don't believe me, you can always check with Amazon: http://www.amazon.com/gp/help/customer/display.html/ref=hp_468512_calculated?nodeId=468512#calculated I think they know what they're talking about. FINAL UPDATE: Now, if someone goes to your site, and buys something from your business (in California) and the shipping address for the product is Nevada, then taxes do not have to be collected.  If they have a billing address in California, and a shipping address in Nevada, and the goods are shipping to Nevada, you do not have to declare tax. If you have a mixture of tangible (computer, mouse, keyboard) and intangible assets (warranty) in a cart, and the shipping address is in California, you charge tax on the tangible assets, but NOT on the intangible assets. Yes, you can charge tax on the whole order.  Yes for most businesses that's ""Good enough"", but I'm not trying to provide the ""good enough"" solution, I'm simply telling you how very large businesses run and operate.  As I've mentioned, I've done several tax integrations using software called Sabrix (Google if you've not heard of it), and have done those integrations for companies like the BBC and Corbis (owned and operated by Bill Gates). Take it or leave it, but the correct way to charge taxes, especially given the complex tax laws of the US and internationally, is to charge per item.  If you just need the ""good enough"" approach, feel free to calculate it by total. Some additional reading: http://en.wikipedia.org/wiki/Taxation_of_Digital_Goods Another possible federal limitation on Internet taxation is the United States Supreme Court case, Quill Corp. v. North Dakota, 504 U.S. 298 (1992),[6] which held that under the dormant commerce clause, goods purchased through mail order cannot be subject to a state’s sales tax unless the vendor has a substantial nexus with the state levying the tax.  In 1997, the federal government decided to limit taxation of Internet activity for a period of time. The Internet Tax Freedom Act (ITFA) prohibits taxes on Internet access, which is defined as a service that allows users access to content, information, email or other services offered over the Internet and may include access to proprietary content, information, and other services as part of a package offered to customers. The Act has exceptions for taxes levied before the statute was written and for sales taxes on online purchases of physical goods." "First of all to answer the basic question ""Is one method correct? Might it depend on local laws?"" Yes it does depend on local laws. Because ultimately the business will have to file forms with the sate/county/city.  These forms are going to ask for the total sales based on the tax category (tax free, x%, y%). Each transaction could have parts that fall into each category. The local taxing authority decides what goes into each category. The local taxing authority also determines how often the business needs to submit the taxes. They can even decide to base the rates used by where the customer lives.  A business is not required to charge directly for sales tax. That is why frequently at sporting events, the price on the menu notes that all sales taxes are included. I suppose not directly charging a sales tax makes the monthly calculation harder, but the state will still get their money. Rounding up at the end of the entire transaction is enough to make sure they collect enough taxes, so they don't have to dip into their profits." You should total the items first, to get $3.00, then add the tax, then round up/down accordingly.  Your two examples above don't offer this option, even though your second example arrives at the same result.  In your first example, a number of items taxed one at a time might result in many .006 results which would round to .01. A long enough list of items would result in an error of many cents depending how many items there are. Totaling first then applying tax results in your saving .004 or losing .005 cents maximum due to rounding.  See A Guide to Sales and Use Tax which is a document put out by the Massachusetts Dept of Revenue. In the chart for tax, it shows that $1.09 is taxed at five cents, but at 5%, it would be 5.45. So, at least for this state, I believe I correctly stated the rounding process. Taxes should not be calculated at the item level. Taxes should be aggregated by tax group at the summary level. The right way everywhere is LINE ITEMS SUMMARY PS:If you'd charge at the item level, it would be too easy to circumvent the law by splitting your items or services into 900 items at $0.01 (Which once rounded would mean no tax). This could happen in the banking or plastic pellets industry.
"JoeTaxpayer nailed it.  Here's another way to look at it: Generally, we invest in something, then might leave it there for a few years, then take it out, but don't touch it in between.  In that case, to get the final amount X(N), we need to take the initial amount, then multiply by growth in the first year, then multiply by growth in the second year, etc. So, for three years, we have: X(3) = X(0) * G(1) * G(2) * G(3) = X(0) * ""average annual growth"" ^ 3 So, here, we see that we want the average annual growth to the power three equal to the product of the annual growth rates, thus, geometric mean: geometric mean = (G(1) * G(2) * G(3)) ^ (1/3) On the other hand, consider a situation where I have three investments X,Y,Z over one year. Now I have, after one year: X(1)+Y(1)+Z(1) = X(0)*G(1,X) + Y(0)*G(1,Y) + Z(0)*G(1,Z) = ( X(0)+Y(0)+Z(0) ) * ""average annual growth"" Now, in this case, if we assume X(0) = Y(0) = Z(0) = 1, i.e. I put equal amounts in each, we see that the average annual growth rate we want in this case is the arithmetic mean: arithmetic mean = (G(1,X) + G(1,Y) + G(1,Z)) / 3 (if we had unequal amounts at the beginning, it would be a weighted average). TL;DR:" "in the U.S. (for @Software Monkey) books are treated just like any other donation, you look at comparable sales: IRS Link. Sounds like a pain to do each book manually. TurbtoTax has ""ItsDeductable"" product that suppose to help you calculate the value of donated items." "Yes, this is a miscellaneous itemized deduction. https://www.irs.gov/publications/p529/ar02.html For this to impact your taxes, you have to be itemizing deductions (have total deductions greater than standard deduction), and the total of all miscellaneous deductions needs to exceed the ""2% floor"" described in the IRS link above." "I'll assume United States as the country; the answer may (probably does) vary somewhat if this is not correct.  Also, I preface this with the caveat that I am neither a lawyer nor an accountant.  However, this is my understanding: You must recognize the revenue at the time the credits are purchased (when money changes hands), and charge sales tax on the full amount at that time.  This is because the customer has pre-paid and purchased a service (i.e. the ""credits"", which are units of time available in the application).  This is clearly a complete transaction.  The use of the credits is irrelevant.  This is equivalent to a customer purchasing a box of widgets for future delivery; the payment is made and the widgets are available but have simply not been shipped (and therefore used).  This mirrors many online service providers (say, NetFlix) in business model.   This is different from the case in which a customer purchases a ""gift card"" or ""reloadable debit card"".  In this case, sales tax is NOT collected (because this is technically not a purchase).  Revenue is also not booked at this time.  Instead, the revenue is booked when the gift card's balance is used to pay for a good or service, and at that time the tax is collected (usually from the funds on the card).  To do otherwise would greatly complicate the tax basis (suppose the gift card is used in a different state or county, where sales tax is charged differently?  Suppose the gift card is used to purchase a tax-exempt item?)  For justification, see bankruptcy consideration of the two cases.  In the former, the customer has ""ownership"" of an asset (the credits), which cannot be taken from him (although it might be unusable).  In the latter, the holder of the debit card is technically an unsecured creditor of the company - and is last in line if the company's assets are liquidated for repayment.   Consider also the case where the cost of the ""credits"" is increased part-way through the year (say, from $10 per credit to $20 per credit) or if a discount promotion is applied (buy 5 credits, get one free).  The customer has a ""tangible"" item (one credit) which gets the same functionality regardless of price.  This would be different if instead of ""credits"" you instead maintain an ""account"" where the user deposited $1000 and was billed for usage; in this case you fall back to the ""gift card"" scenario (but usage is charged at the current rate) and revenue is booked when the usage is purchased; similarly, tax is collected on the purchase of the service.  For this model to work, the ""credit"" would likely have to be refundable, and could not expire (see gift cards, above), and must be usable on a variety of ""services"".  You may have particular responsibility in the handling of this ""deposit"" as well." Simple.  Say in 2012 you were up 50% (brilliant) but then in 2013 you were down 50% (sorry). i.e. if you started with $1000, you were up to $1500, then down to $750. You lost $250 overall. If you were to compute the mean of the percentages using each method, then: Arithmetic mean: The average of +50% and -50% (really 150% and 50% of each period's initial value) is zero, not up or down. Geometric mean: 1.5 * .5 = .75, i.e. you are down 25% over 2 years, or about 13.4% per year. It should be clear the Geometric makes more sense in such a case. TWRR = (2012Q4 x 2013Q1 x 2013Q2) ^ (1/3) = ?? (1.1 * .809 * 1.29) ^ (1/3) = 1.047 or 4.7% return. No imaginary numbers needed.  But. Your second line there is wrong $15,750 - $15,000 - $4,000 ? The $15K already contains the $4k, why did you subtract it again?  This a homework problem? Your 1&2 are the end of that chapter. You can't convert for that year again, and must wait 30 days to convert in the new tax year.  For example, each year for over a decade, I've helped my mother in law with this. In May, we convert a chunk of money/stock to Roth. In April, I'll recharacterize just enough so she tops off her 15% bracket but doesn't hit 25%. 30 days later, the new conversion happens. All the Roth money is money now taxed at 15%, which, in an emergency, a need for a lot of cash, will avoid the potential of 25% or higher, tax. You see, your 3 never really happens. "There is no numerical convention in finance that I have ever seen.  If you look at statements or reports that measure growth when the starting value is negative or zero, you typically see ""n/a"" or ""-"" or ""*"" as the result.  Any numerical result would be meaningless.  Suppose you used 100% and another company had a legitimate 150% gain - where would the 100% change rank? What do my manager and investors expect to see? As a financial analyst - I would not want to see 100%.  I would instead rather see something that indicates that the % change is meaningless.   As an example, here's the WSJ documentation on change in Net Income: Net Income percent change is the change from the same period from a year ago. Percent change is not provided if either the latest period or the year-ago period contains a net loss.  Thinking about it in another context: Yesterday you and your friend had no apples. Today you have 1 and your friend has 20.  What percentage increase did you both have? Did you both have a 100% increase? How can you indicate that your friend had a larger ""increase""? In that case (and in finance), the context needs to turn from a percentage increase to an absolute increase.  A percentage increase is that scenario is meaningless." The vendor needs to do this using apportionment, according to the VAT rules for mixed supplies: If you make mixed supplies and the individual supplies are not liable to VAT   at the same rate then you need to work out the tax value of   each supply in order to calculate how much tax is due. If the tax   value is based on the total price you charge (see paragraph 7.3) you   do this by splitting that price between the supplies. This is called   an apportionment ... There is no special method of apportionment ... However, your calculations must be fair and you must be able to justify them. It is usually best to use one of the methods shown in section 32. The section 32 referred to really relates to apportioning use between business and non-business purposes, but it implies that splitting up the total price in proportion to the original prices would probably be fair. So in your example the vendor might split the £5 discount equally between the spoon and the carrycot as they had the same gross cost, and pay VAT as if each had cost £7.50 gross. The vendor could also do it in proportion to their net (pre-VAT) prices and thus apportion a bit more of the discount to the carrycot than the spoon, but as this would lead to them paying slightly more tax overall they probably wouldn't choose to. However, none of this is likely to be too relevant to a consumer, since in the UK prices must be presented as the gross (VAT-inclusive) amounts and so the discounts will also apply to those amounts. It will of course affect how much of the purchase price the vendor ends up paying on to the government and thus might indirectly affect what discounts the vendor is willing to offer. "Payment gateways such as Square do not normally withhold tax. It is up to you to pay the appropriate tax at tax time. That having been said, Square does report your payments to the IRS on a form 1099-K if your payments are large enough. According to Square, you'll get a 1099-K from them if your total payments for the year add up to $20,000 AND more than 200 transactions.  Whether or not they report on a 1099-K, you are required to pay the appropriate taxes on your income.  So now the question becomes, ""Do I have to pay income tax on the proceeds from my garage sale?"" And the answer to that question is usually not. When you sell something that you previously purchased, if you sell it for more than you paid for it, you have a capital gain and need to pay tax on that. However, generally you sell things in a garage sale at a loss, meaning that there is no tax due.  If you make more than $20,000 at your garage sale and the IRS gets a 1099-K, the IRS might be curious as to how you did that with no capital gain. So if you sell any big ticket items (a bulldozer, for example), you should keep a record of what you paid for it, so you can show the loss to the IRS in the event of an audit." "Total Return is the percent change in value (including andy dividends) of an instrument.  The ""trailing 12-month"" means that your starting point is the value 12 months ago.  So the formula is: where V is the value of the instrument on the reference date, V0 is the value of the instrument 12 months prior to the reference date, and D is the amount of dividends paid between the two dates." If I is the initial deposit, P the periodic deposit, r the rent per period, n the number of periods, and F the final value, than we can combine two formulas into one to get the following answer: F = I*(1+r)n + P*[(1+r)n-1]/r In this case, you get V = 1000*(1.05)20 + 100*[(1.05)20-1]/0.05 = 5959.89 USD. Note that the actual final value may be lower because of rounding errors. So for quarters So, if Q1's value was 10 and Q2's value was 25 For closing or opening prices, I would use closing prices.  For instance, some used Adjusted Close or Close on Yahoo Finance (see this example of AAPL). Added Note: In your example, for your example, you'll want to take the absolute value of the denominator (aka: divisor), so an Excel formula might look like the below example ... ... where the new and old are cells. Apparently it's based on either the address of the seller or vendor or your shipping address; from the AccurateTax.com blog post Destination and Origin Based Sales Tax: ... a few states have laws that are origin-based, where products that are shipped to the customer are taxed based on the location of the business itself. As of this writing, these states are Most states use destination-based sales tax, which defines the source of the transaction to be the destination at which the product will eventually be used, or the address to which the product is shipped. ... The following states [and districts] operate on a destination-based model at the time of this writing: The page Do I Charge Sales Tax or Not? from about.com seems to (somewhat) clarify that if the business is located in a state (or other jurisdiction) with an origin-based sales tax, then they will charge you the sales tax for their state and, presumably, not the sales tax for the state of the shipping address. Here's how capital gains are totaled: Long and Short Term. Capital gains and losses are either long-term or   short-term. It depends on how long the taxpayer holds the property. If   the taxpayer holds it for one year or less, the gain or loss is   short-term. Net Capital Gain.  If a taxpayer’s long-term gains are more than their   long-term losses, the difference between the two is a net long-term   capital gain. If the net long-term capital gain is more than the net   short-term capital loss, the taxpayer has a net capital gain. So your net long-term gains (from all investments, through all brokers) are offset by any net short-term loss.  Short term gains are taxed separately at a higher rate. I'm trying to avoid realizing a long term capital gain, but at the same time trade the stock. If you close in the next year, one of two things will happen - either the stock will go down, and you'll have short-term gains on the short, or the stock will go up, and you'll have short-term losses on the short that will offset the gains on the stock.  So I don;t see how it reduces your tax liability.  At best it defers it.