# Same Bank Account Number, Different Branch



## jayl (15 Sep 2008)

I returned home from two weeks holiday yesterday to discover a strange transaction on my bank account last week, which turned out to be a cash withdrawal from my branch. Apparently someone with the same account number as me but in a different branch of the same bank (same county) made a cash withdrawal from my branch, and the teller incorrectly entered my sort code instead of theirs, resulting in the withdrawal coming out of my account.

The bank were very efficient and promptly returned the money to my account and were extremely apologetic which I'm pleased with, but a couple of things about the whole ordeal are frustrating me:


I know the combination of sort code and account number are always unique but in practice do banks actually have more than one account with the same account number? Seems a bit ridiculous, with 8 digits I would have thought each bank would have more than enough room to give every account a unique number?
The holder of the other account withdrew the money from my branch, which obviously explains how easy a mistake it was to make, but it concerns me that there's a large chance this might happen again. There's a possibility that the person lives near my branch and might bank there frequently despite his main branch being elsewhere. Thus, this error could happen again in the future.
I'd like to get the opinion of those in the know as to whether or not banks do have multiple accounts with the same account number. Also, I'm thinking of asking the bank to give me a new account number. Would I have to go through the process of closing the account and opening a new one and transferring all my direct debits to do this or can the bank simply issue me a new account number? And is it possible to ensure that the new account number is at least not the same as someone in the same county?

Any thoughts?


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## ClubMan (15 Sep 2008)

jayl said:


> I returned home from two weeks holiday yesterday to discover a strange transaction on my bank account last week, which turned out to be a cash withdrawal from my branch. Apparently someone with the same account number as me but in a different branch of the same bank (same county) made a cash withdrawal from my branch, and the teller incorrectly entered my sort code instead of theirs, resulting in the withdrawal coming out of my account.
> 
> 
> I know the combination of sort code and account number are always unique but in practice do banks actually have more than one account with the same account number?


Surely the answer is "yes" based on your own direct experience here?


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## TarfHead (15 Sep 2008)

My response is based on my knowledge of one bank; may not be true for all banks.



jayl said:


> I know the combination of sort code and account number are always unique but in practice do banks actually have more than one account with the same account number?


 
Yes. While the incidence of this is, I believe, low, it does happen.



jayl said:


> Seems a bit ridiculous, with 8 digits I would have thought each bank would have more than enough room to give every account a unique number?


 
An 8 digit bank account number is, in practice, a 7 digit number with the 8th digit being a check-digit. Also, some values are discounted as being unsuitable, e.g. all 7 digits the same (1111111), digits in sequence (3456789). In short, there aren't as many values available for use as one might think. And the practice of re-using number arose out of running out of numbers



jayl said:


> Also, I'm thinking of asking the bank to give me a new account number. Would I have to go through the process of closing the account and opening a new one and transferring all my direct debits to do this or can the bank simply issue me a new account number?


 
Yes, you would have to close the account and open a new one to get a new number. The bank, in light of the circumstances, may be able to facilitate you in re-directing DDs, but, equally, may not.



jayl said:


> And is it possible to ensure that the new account number is at least not the same as someone in the same county?


 
Almost certainly, No


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## jayl (15 Sep 2008)

ClubMan said:


> Surely the answer is "yes" based on your own direct experience here?



I suppose what I was thinking here was the possibility that the bank were lying?

Thanks for that information TarfHead, it's very useful.


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## Stronge (29 Sep 2008)

As far as I know no two people have the same bank account no. Not even in different branches.  The banks may reuse numbers from closed account after a certain number of years.


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## MugsGame (29 Sep 2008)

> no two people have the same bank account no. Not even in different branches.


http://www.askaboutmoney.com/showthread.php?t=60302#15


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## Stronge (29 Sep 2008)

Thanks for that link, I reallly was under the impression that in all the major banks that your number was unique to you within that  banking group.  I realise that other banks could have the same a/c numbers but a different sort code would be necessary. You live and learn !


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## kimmage (30 Sep 2008)

Stronge said:


> Thanks for that link, I reallly was under the impression that in all the major banks that your number was unique to you within that  banking group.  I realise that other banks could have the same a/c numbers but a different sort code would be necessary. You live and learn !




I worked for Bank of Ireland and I know every eight digit account number is unique.  Also, if you look now (accounts opened recently), the first digits are 8... and in 1950's it was 1...

AIB however, use a "number line" system where 00000-000 the first five digits are "your" unique number to that branch and the remaining three are your account code.  EG 00000-001 Current 00000-002 Savings etc.

Each branch could issue the same number, the only way they are different would be by Sort Code!


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## VanHeusen (4 Oct 2008)

Stronge said:


> Thanks for that link, I reallly was under the impression that in all the major banks that your number was unique to you within that  banking group.



I still am under that impression - at least in the case of BoI. The reason: When I call BoI 365 phone banking, their system asks for my 8-digit account number only. No sort code. Based on that, I would say my account number IS unique to me within BoI.


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## pudds (4 Oct 2008)

I cant see why if there is a shortage of 8 digit a/c numbers, why haven't they moved to 10 or 12 digit a/c numbers, or could the system not cope with this, surely not  (they do it with credit cards) 

just my simple opinion lol


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## TarfHead (4 Oct 2008)

VanHeusen said:


> . Based on that, I would say my account number IS unique to me within BoI.


 
That is not the only information they ask you for. You are also required to provide your 365 Online 6 digit ID. If they got came across an instance of an account number being duplicated. they would request further detail to ensure they were dealing with the correct account holder.

With regard to to moving to 10 or 12 digit account numbers, the IT costs would be prohibitive. And credit card numbers contain a level of repetition - the first 8 digits (BIN) are common within card issuer & card type.

Your account number may be unique within BoI, but that may not always be true.


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## VanHeusen (5 Oct 2008)

TarfHead said:


> That is not the only information they ask you for. You are also required to provide your 365 Online 6 digit ID.



Maybe we are using different BoI 365 *phone* banking, but I am pretty sure that the automated system IDs me by asking for the 8 digit account number and then three random digits from my password. 
BoI 365 *online* 6 digit ID is required for BoI 365 *online *banking.


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## mathepac (5 Oct 2008)

TarfHead said:


> ...
> With regard to to moving to 10 or 12 digit account numbers, the IT costs would be prohibitive. ...



That old chestnut - "the computer system can't handle it without spending mega bucks". In reality, the IT cost or complexity of storing, accessing, checking or reproducing an 8, 10, 12, 16 or even greater digits (or characters) for A/C references are minimal. There wouldn't even be a need to convert existing 8-digit A/C numbers to the new format, unless duplicates were a problem. 

The IBAN system used in Europe already caters for 12 character A/C numbers (Andorra for crying out loud) or 16 character (Czech Republic). The real costs would be in retraining people and changing all those little pre-printed withdrawal and lodgment dockets. My statements have my IBAN already printed on them each month, so there is no reason(or excuse) I can see to invent a better mouse-trap in order to ensure uniqueness.


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## TarfHead (5 Oct 2008)

mathepac said:


> .. In reality, the IT cost or complexity of storing, accessing, checking or reproducing an 8, 10, 12, 16 or even greater digits (or characters) for A/C references are minimal..



So, the costs of changing every program and database that stores account number as an 8 digit number would be minimal ? Please explain - you could have the secret of alchemy. If you are advocating the migration of using the current 8-digit account number to IBAN for all account-number based processing, please explain how that could be done with minimal cost.


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## TarfHead (5 Oct 2008)

VanHeusen said:


> Maybe we are using different BoI 365 *phone* banking, but I am pretty sure that the automated system IDs me by asking for the 8 digit account number and then three random digits from my password.
> BoI 365 *online* 6 digit ID is required for BoI 365 *online *banking.



So, I made the error of citing Online ID when I should have cited password ? Doesn't invalidate my point. If you were the 'owner' of an account number that has been re-used, you would have been broken out of the call to talk to an agent.

Your account is not always unique. Simple as !

Maybe next time I shouldn't post to AAM when on my 4th can of beer .


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## VanHeusen (6 Oct 2008)

TarfHead said:


> If you were the 'owner' of an account number that has been re-used, you would have been broken out of the call to talk to an agent.



At 1:00 AM? Or on a Sunday? I doubt it. 
Or would they perhaps play a message: "Hello, this is 365 phone. We screwed up and assigned you a duplicate account number, therefore you cannot avail of a service that we advertise as available 24/7 because our call center is closed past midnight. Thank you for calling."



TarfHead said:


> Your account is not always unique. Simple as !



Yup, you are right. It would defeat the purpose of using account numbers as identifiers for the phone service, it would defeat the purpose of having an automated phone system, but hey, it is possible.


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## Mpsox (6 Oct 2008)

It is theoretically possible for 2 people to have the same account number, however, it would be unusual

Most banking systems look not just at the account number but also at the 6 digit sort-code. Their systems will perform a mathimatical algorithim calculation for the 14 digits in the sort code and account number and providing the answer to that equation is a speicific number, the overall sort-code and account number is validated. It would be statistically feasible therefore for 2 people to have the same account numbers at different branches. Highly unusual however, not heard of it happening in Ireland but have heard of it in the UK where they use a similer system


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