Why is routing number called ABA/ABN number?
The ABA number you speak of is more accurately called the Routing Transit Number.   http://en.wikipedia.org/wiki/Routing_transit_number A routing transit number (RTN) is a nine digit bank code, used in the   United States, which appears on the bottom of negotiable instruments   such as checks identifying the financial institution on which it was   drawn. This code was designed to facilitate the sorting, bundling, and   shipment of paper checks back to the drawer's (check writer's)   account. The RTN is also used by Federal Reserve Banks to process Fedwire funds   transfers, and by the Automated Clearing House to process direct   deposits, bill payments, and other such automated transfers. The RTN number is derived from the bank's transit number originated by   the American Bankers Association, which designed it in 1910.[1] I am going to assume that the euphemistic ABA Number has been shortened by whoever told you about it and called it the ABN.  Perhaps American Bank Number.  Either way, the technical term is RTN. Perhaps a comment or editor can straighten me out about the ABN. There is an international number known as the SWIFT number that serves the same purpose worldwide. http://en.wikipedia.org/wiki/ISO_9362 ISO 9362 (also known as SWIFT-BIC, BIC code, SWIFT ID or SWIFT code)   defines a standard format of Business Identifier Codes approved by the   International Organization for Standardization (ISO). It is a unique   identification code for both financial and non-financial   institutions.[1] The acronym SWIFT stands for the Society for   Worldwide Interbank Financial Telecommunication. When assigned to a   non-financial institution, the code may also be known as a Business   Entity Identifier or BEI. These codes are used when transferring money   between banks, particularly for international wire transfers, and also   for the exchange of other messages between banks. The codes can   sometimes be found on account statements. With number of Banks increasing every country at some point in time adopted an Identification code. In US these are called ABA number because they are allocated by American Bankers Association, in UK Sort Codes ... like wise for other countries. See list here http://en.wikipedia.org/wiki/Bank_code In some countries the numbers are given by Central Bank.   To enable internationl payments, the SWIFT body apart from message formats, allocated a  SWIFT BIC [Bank identification Code] so that Banks can be globally identified. Currently  IBAN being adopted in Europe & Australia to identify an Account [at a Bank] Uniquely across globe. In essence these number help uniquely identify a Location/Bank/Branch. The clearing house route the payments or collection instruments to the correct Bank on the basis of this number.
Emergency funds, by the name it implies that they should be available on hand at a very short notice if needed. Conservation of principal (not withstanding inflation, but rather in absolute terms) is also a very important criteria of any kind of account that you will use to save the emergency fund. I would suggest the following breakup. The number in brackets signifies the amount of per month expenses that you can keep in that account. = total 6 months living expenses Most transactions that the bank performs for you are electronic ACH transactions, so the costs to them are minimal in the long run.  Most banks do it now to keep up with the competition.  Almost every bank does it now, so they have to do it to attract new business and keep existing customers. Also, the more you rely on the bank and use them to pay bills, the more they learn about you over time and can use that data in overall marketing plans.  It's easier for them to record it into their system if it is all electronic to begin with. It's to legally allow you to buy/ sell securities on behalf of others and to give advice. Different tests allow different things. 66 is for the basics: stocks and bonds etc. I believe 31 is for insurance or something. I'm not too sure the specifics I'm probably wrong about which test is which though. Basically speaking, Japanese bank accounts are identified by three numbers: The four digit Bank number.  For example 0005 is Mitsubishi Tokyo UFJ Bank The three digit Branch number. For example 001 = Main branch for Mitsubishi. The account number.  This is your account number. Your ATM Cash Card and passbook will have these numbers on it in the format XXXX-YYYY-ZZZZZZZZ.   When you use an ATM to send money to someone else (like your landlord) you but in these three numbers or use the search feature instead for the first two.  This works the same whether you are talking about Mitsubishi, Mizuho, etc.  The only thing to note is that while real banks use locations for the branch number (i.e. Ueno branch, Marunouchi branch, etc.), online only banks like Sony Bank (MoneyKit), Rakuten Bank, SBi, etc. use fake locations like colors, etc.  This doesn't matter much though. Japan Post bank is technically not a bank and uses a totally different numbering system, though recently they have come up with a strange formula to convert your JP Bank account number into a normal bank account number so you can send payments to it as shown above). All of this is basically for domestic transfers only, though.  If you want to transfer money internationally, there are two basic ways: The official way.  Go to your bank overseas, and give them the SWIFT code and account code for your bank (likely the branch code will be necessary as well).  The problem here is that they will likely charge a high fee for sending the money, and your bank in Japan may also charge a high fee for receiving it!  (In addition to any currency conversion fees).  A second problem is that only the very major banks even have SWIFT codes. Use a money transfer service that can handle both Japan and your other country.  For example, you can use 2 Paypal accounts (Only in the direction of From Japan To overseas, though!), or you can use something like MoneyBookers Either way IBAN is a European standard and isn't used in Japan. If you just want to spend some money in Japan, the most convenient way is probably a foreign visa debit card.  Or, you can use a foreign ATM card in Japan to withdraw cash and then deposit it into your Japanese account. "this is purely psychological.  most people are absolutely terrible at keeping track of their finances.  to the point where they will use multiple separate accounts for different types of spending or savings goals.  when the average person tells the banker they want an account for the money they are saving, they get handed a ""savings account"" and don't bother to question how it is different from a checking account." It's safe. You give people those numbers every time you write a check.  If a check is forged, and doesn't have your signature on it, the bank has to return the money to you; they get it back from the other bank, who takes whatever action it deems necessary against the forger. They've been doing this for a few hundred years, remember. First, they don't have an obligation to provide a service for a non-customer.  In theory, the could even refuse this service to account holders if that was their business model, although in practice that would almost surely be too large of a turn-off to be commercially feasible.  Non-account holders aren't paying fees or providing capital to the bank, so the bank really has no incentive or obligation to tie up tellers serving them. Maybe as importantly, they have a legitimate business reason in this case as stated.  The fact that the bill passed whatever test the teller did does not, of course, ensure that the bill is real.  They may (or may not) subject it to additional tests later that might be more conclusive.  Making you have an account helps ensure that, in the event they do test it and it fails, that (a) they know who you are in case the Secret Service wants to find you, and (b) they can recover their losses by debiting your account by the $100.  This isn't foolproof since any number of bad things could still happen (identity theft, closing account before they do additional tests, bill passing later tests, etc.), but it does give them some measure of protection. "In Europe in most of the countries there is also a thing called ACH. In UK there is a thing called BACS and in other countires there are other things. Essentially every country has what is called a ""Low value Net Settlement System"" that is used to transfer funds between accounts of different banks. In US there is rounting number, in UK there is a Sort Code, in Indonesia there is a sort code. Essentially a Bank Identifier that is issued by the Governing body within respective countires.   Certian identifiers like SWIFT BIC [Bank Identification Code] are Unique across world." Typically 'current' means the account from which you do your day-to-day banking (also called 'checking') and 'savings' is an interest earning account, from which you might occasionally take money. However...you can actually attach these labels (for ATM purposes) to any account you want. They don't have to be your actual checking or savings accounts.  I have 'current' attached to my personal account and 'savings' on the account I hold jointly with my wife. They are just labels you attach to different accounts. Probably because large chains can absorb the loss from fraud better than small stores do.  Thus, small stores want to ensure that the person holding the card is the same as the name on the card. For the clearing house, only the routing number and the check amount [which gets encoded before its presented to clearing] is important. The check numbers were put in as a fraud prevention mechanism to ensure that one check was only presented once and that it was issued to a particular account. Typically issued in sequence.   So as your account is new, the bank may have a mechanism to verify the checks [maybe based on amount and other info]. If your volume of check issuing increases, they may start putting in a check number to better track. "I'm not sure I understand your question, but I'll try to answer what I think you're asking. I think you're asking this: ""A US bank receives a wire transfer from a Chinese bank. How does the   US bank ensure there's any money in fact arriving before crediting the   destination account?"" Well, the way wire transfers work is that the US bank would debit the senders' account with that US bank. So the US bank in fact transfers the money between two internal accounts: debit to the Chinese bank's account with that US bank and credit the destination customer account. If the Chinese bank doesn't have an account with the destination US bank - a third party intermediary is used that both banks have accounts with. Such third party will charge an additional fee (hence sometimes the wire transfer fees are slightly higher than you initially know when sending the money, the third party would debit from the transfer amount). ""Regular"" IBAN/ACH transfers work through regulatory channels that ensure integrity and essentially use a regulatory bank as that third party. But because they're done in batches and not on-line, they're much cheaper, and the accounting is for the whole batch and not each transfer separately. But batch processing means it will take a day or two of processing, while wire transfer takes hours at most." Another explanation is that they keep your money three days to make money with it, because they can. The other reasons might have been valid 100 years ago, and no bank would voluntarily cut that down until forced by law. Example: In Europe, bank to bank transfers used to take three days, until a law forced them to give next day, and suddenly it was possible. "There's something wrong with your story. The IBAN contiains two check digits, and the method used to compute them guarantees that any single digit error will be caught. So it's impossible that ""HSBC screwed up the last digit of my IBAN"" because if that were the case, the resulting IBAN would not be valid and be rejected by the computer when it was entered at your bank." Most bank accounts offer automatic bill pay as well. They don't rely on support from the bill you're paying, I think they basically just mail a check with your account number on it