Is it possible to block previously authorized ACH access?
I had a similar situation a while ago, and here's what I learned: What are our options here to ensure that this company can't retry to take our money again via ACH? Close existing account and create a new one that has different account number? Yes. As a temporary solution keep ~$0 balance in the account so that their request for $840 can't be fulfilled? However, would our bank incur any fees because of insufficient funds each time the other company tries to charge us again? Bad idea. You may incur penalties for returned payment, or the bank may honor the payment and charge you overdraft fees. Provide to our bank the service termination notice that proves that we   are not in business with the other company anymore and effectively   block them. However, termination notice has only our signature Bank doesn't care. ACH withdrawal is akin to a check. The assumption is that the other side has entitlement. You can put stop payment once its processed and try to reverse it claiming fraud, but the end result will be #1: you'll end up getting a new account set up, while they try to recover the money. This is one of the reasons I'm reluctant allowing standing ACH authorizations any more. Generally, the American banking system is very much geared against the consumers, and in many ways is very retarded. In a more advanced countries (which is almost any other country than the US), the standing withdrawal authorization goes through your bank and can be revoked.
"(I agree with the answers above; would just like to make a couple of additional points.) It's a good and simple strategy to try it out with a small amount as suggested by @JoeTaxpayer♦. It's also generally safe to assert that card issuers currently don't receive or actively look at itemized transaction details. But that does not mean they cannot in the future. Some stores utilize level 3 data processing, which tells the card issuers exactly what you bought in a transaction. An example of level 3 data being utilized to reject rewards is with Discover, which announced a 10% cashback reward for any transactions made with Apple Pay last year. It later introduced an additional term to exclude gift card purchases. And this has been verified to be effective - no more reward on gift card purchases; clawback of cashback on existing gift card transactions. As far as I know, Amex does receive and look at some level 3 data retrospectively. That does not necessarily mean they will claw back your cashback after initially rewarding the 6%. But it might show up if you ever trigger an account review, and be used as evidence of your ""abuse"" of the program (which BTW is defined rather subjectively). There has been many cases of account shutdowns because of this. Card issuers are also trying to do a better job preventing ""abuses"" by proactively setting caps on rewards (as opposed to closing those accounts afterwards and taking the rewards away altogether). Given the trend in recent years, I have to speculate that at some point the card issuers would put clear language in the terms against gift card purchase and enforce it effectively (if they haven't already). This reward game is constantly changing. It's good while it lasts. Just be prepared and don't get surprised when things go south." If bank B has a transfer limit set, you bet that there is a nice reason for that. Either risk of fraud, liability, client preferences, profiling, credit scoring, etc, etc. For a bank, the cost of denying something [1] is way lower than the potential damages and liabilities of allowing something to go through.  Regarding your concerns for the ACH, here is the summarized transaction walkthrough source: An Originator– whether that’s an individual, a corporation or another entity– initiates either a Direct Deposit or Direct Payment transaction using the ACH Network. ACH transactions can be either debit or credit payments and commonly include Direct Deposit of payroll, government and Social Security benefits, mortgage and bill payments, online banking payments, person-to-person (P2P) and business-to-business (B2B) payments, to name a few. Instead of using paper checks, ACH entries are entered and transmitted electronically, making transactions quicker, safer and easier.  The Originating Depository Financial institution (ODFI) enters the ACH entry at the request of the Originator.  The ODFI aggregates payments from customers and transmits them in batches at regular, predetermined intervals to an ACH Operator.  ACH Operators (two central clearing facilities: The Federal Reserve or The Clearing House) receive batches of ACH entries from the ODFI.  The ACH transactions are sorted and made available by the ACH Operator to the Receiving Depository Financial Institution (RDFI).  The Receiver’s account is debited or credited by the RDFI, according to the type of ACH entry. Individuals, businesses and other entities can all be Receivers.  Each ACH credit transaction settles in one to two business days, and each debit transaction settles in just one business day, as per the Rules.  Take heed of this like:  The Originator initiates a direct deposit/payment transaction. In your scenario, the originator would be B. But since the transaction amount is higher than the limit, B would not even initiate the ACH transaction. The request would be denied. So the transaction would look like this: [1] Usually this cost comes down to just the processing costs of the denied transaction (and it is rather fail-fast like). For the other parties involved it may have additional costs (missed deadlines, penalties for not fulfilling an obligation, fines, etc), but for the bank that is irrelevant. Hence why I pay bill by bill and don't authorize automatic withdrawals. Are you telling me your online banking and/or utility company don't allow you to make non automatic payments online?  If so I guess thats the answer to OP's question... You claimed that you could pick out stolen funds, hidden within the block chain, by examining transactions.  I pointed out that stock transactions are all widely published, and asked if you could pick out which trades were done using illicit information.  The parallel is clear. With Mint you are without a doubt telling a third party your username and password.  If mint gets compromised, or hires a bad actor, technically there isn't anything to stop shenanigans.  You simply must be vigilant and be aware of your rights and the legal protections you have against fraud. For all the technical expertise and careful security they put in place, we the customers have to know that there is not, nor will there ever be, a perfectly secure system. The trade off is what you can do for the increased risk.  And when taken into the picture of all the Other* ways you banking information is exposed, and how little you can do about it, mint.com is only a minor increase in risk in my opinion. *See paypal, a check's routing numbers, any e-commerce site you shop at, every bank that has an online facing system, your HR dept's direct deposit and every time you swipe your debit / credit card somewhere. These are all technically risks, some of which are beyond your control to change.  Short of keeping your money in your mattress you can't avoid risk.  (And then your mattress catches fire.) "From my days in e-commerce they break down like this? The company doesn't know a debit from a credit card.  Got the Visa logo, then it is a Visa through the company's payment gateway.  The gateway talks to the bank and that is where the particulars for money is figured out. When I programmed gateway interfaces, I had the option to ""authorize"" or check for funds (which didn't reserve anything, just verified funds existed), run for batch (which put a hold on the funds and collected them at the end of the night) or just take the money. Most places did a verify during the early checkout stages and then did a batch at the end of the night.  The nightly batch allows a merchant to cancel a transaction without getting charged a fee. The ""authorize"" doesn't mean the money is tied up, although that might be your banks policy.  Furthermore, an authorize can only last for so many days.  This also explains why most of your banks don't report your transactions to you the day of.  There is a bunch more activity on your card than the transactions that complete." "My gym has a habit of randomly increasing our monthly payment with a $20 ""Special Fee"" a couple times a year.   This charge was not initiated until after I signed up, and signed authorization for a set monthly fee. The agreement I signed included no wording of this fee, so I have not given them permission to charge me this fee. I also have received no type of notification of this fee prior to it being charged to my credit card on file.   This seems very illegal to me. Am I right? What course of action might I have to get this stopped?" Deliberately breaking transactions into smaller units to avoid reporting requirements is called structuring and may attract the attention of the IRS and/or law enforcement agencies.  I'm not sure what the specific laws are on structuring with respect to FBAR reporting requirements and/or electronic transfers (as opposed to cash transactions).  However, there's been substantial recent publicity about cases where people had their assets seized simply because federal agents suspected they were trying to avoid reporting requirements (even if there was no hard evidence of this).  It is safer not to risk it.  Don't try to structure your transactions to avoid the reporting requirements. US checking accounts are not really secure, though many people use them. One form of check fraud has been highlighted by Prof. Donald Knuth and carried out by Frank Abagnale, as portrayed in the film Catch Me If You Can. Basically, anyone can write a check that would draw from your account merely by knowing your account number and your bank's ABA routing number.  With those two pieces of information (which are revealed on every check that you write), anyone can print a working check, either using a laser printer with MICR (magnetic ink character recognition) toner, or by placing an order with a check-printing company.  The only other missing element is a signature, which is a pretty weak form of authentication. When presented with such a check, your bank would probably honor it before finding out, too late, that it is fraudulent. A variant of this vulnerability is ACH funds transfers.  This is the mechanism through which you could have, say, your utility company automatically withdraw money from your account to pay your bill.  Unfortunately, the transfer is initiated by the recipient, and the system relies largely on trust with some statistical monitoring for suspicious patterns. Basically, the whole US checking system is built with convenience rather than security in mind, since other institutions are able to initiate withdrawal transactions by knowing just the ABA number and account number.  In practice, it works well enough for most people, but if you are paranoid about security, as you seem to be, you don't want to be using checks. The European system, which has largely eliminated checks in favor of payer-initiated push transactions, is safer by design. I'm always hesitant to use local credit unions because I love accessing all atms fee free, having services available 24/7, having robust, safe and audited online services, and having a big enough bank that all major third party tools interface with it.   Joe Schmo Local Credit Union has a lot of good services, but audited and secure online banking? No fee nationwide ATMs? Native interfacing to major tools? I just don't see it often.   I shudder to think of the security at small bank websites, frankly. The RDFI (Receiving Depository Institution) is the place where you keep your money and where the Debit is going to be made. Unfortunately the Debit did not go through for some kind of regulatory reason that I don't understand. You could ask them why people are not allowed to make ACH Debits there or you can try to pay through a different bank. I'm looking for another one right now. Here's what I've found: Los Alamos National Bank (www.lanb.com) has tokens ($5?), but I think they only open accounts for New Mexico residents. I've had one for several years. USAA Savings Bank (usaa.com) has tokens ($5 or free, I don't remember). I'm pretty sure you do NOT need to be a USAA member to open an account. I've had one for a couple of years. Several banks (Frost Bank, American National Bank of Texas, Amegy Bank, and probably many, many more) offer them as part of their Treasury Management accounts, meant for big businesses and charged for accordingly. Happy State Bank (in, where else, Happy, Texas) has a web page saying they have them but their services charges were more than I wanted to pay. ClearSky Bank (an Internet bank started by Chesapeake Bank) claims on their web page to have them but I haven't verified that yet. Still looking... https://twitter.com/webster/status/906346071210778625  Important to know that people just discovered the pin number to thaw your credit (after you initialize a credit freeze) on Equifax is just the timestamp on when you request it. This is bad news because if someone is aware of a time frame, they may be able to brute force this if they don't have proper protection (which, let's be honest, at this point let's just assume they don't). This is lazy coding at it's finest.  Quite a few today have confirmed this. I am able to set this up for my tenants by providing them with a form to fill out so that they provide their name and bank account information, and then I gave that to my bank and they establish a recurring ACH transfer.  This way the tenant never gets my bank information. One note about this, I had a tenant break her lease and move out.  She notified me a couple of days before the first of the month, and by the time she had moved a few days later the rent had been automatically paid.  She called her bank and asked them to reverse the most recent transaction so she could have that month's rent refunded, and much to my surprise, they did.  So the financial transfer is not necessarily one-way. This is in the US. Gnucash uses aqbanking, so I'd suggest looking at aqbanking to see if it will do what you want. It seems to be actively developed (as of 26.2.2011), but the main page is in German and my German is a bit rusty... You might also try asking on the gnucash-users list.