| Account number verification. [message #198310] |
Fr, 04 Februar 2005 05:25 |
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Sort codes can be checked for accuracy, but what about account numbers
at UK banks.
I ask because I signed up to ebay today and they needed a sort code and
account number. What if someone gave a real sort code but made up the
account number. Could the number be checked; whether the specific
number itself or the algorithm?
TIA.
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| Re: Account number verification. [message #198313 ] |
Fr, 04 Februar 2005 07:24 |
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"BigMomma" <bigmomma [at] mommaisbig.co.uk> wrote in message
news:ctutin$4pa$1 [at] news6.svr.pol.co.uk...
> Sort codes can be checked for accuracy, but what about account numbers
> at UK banks.
>
> I ask because I signed up to ebay today and they needed a sort code and
> account number. What if someone gave a real sort code but made up the
> account number. Could the number be checked; whether the specific
> number itself or the algorithm?
>
> TIA.
Best to ask this in
uk.people.consumers.ebay
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| Re: Account number verification. [message #198314 ] |
Fr, 04 Februar 2005 07:44 |
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On Fri, 04 Feb 2005 04:25:56 +0000, BigMomma
<bigmomma [at] mommaisbig.co.uk> wrote:
>Sort codes can be checked for accuracy, but what about account numbers
>at UK banks.
>
>I ask because I signed up to ebay today and they needed a sort code and
>account number. What if someone gave a real sort code but made up the
>account number. Could the number be checked; whether the specific
>number itself or the algorithm?
I believe the reason eBay ask for this information is to set up a
direct debit for the seller to pay his charges from. If you give
incorrect information then direct debit would fail and they'd be back
to you asking for payment by some other method.
Chris
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| Re: Account number verification. [message #198331 ] |
Fr, 04 Februar 2005 12:38 |
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BigMomma wrote:
>
> Sort codes can be checked for accuracy, but what about account numbers
> at UK banks.
>
> I ask because I signed up to ebay today and they needed a sort code and
> account number. What if someone gave a real sort code but made up the
> account number. Could the number be checked; whether the specific
> number itself or the algorithm?
http://www.afd.co.uk/tryit/ has various checking services including:
Bank Lookup
Bank Search
Bank Account Validation
the last of which allows entry of sort code & a/c number, so presumably
ebay can do the same sort of thing?
I did a quick check on the Validation and it came back with the correct
results when I entered true details and false details
Allan
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| Re: Account number verification. [message #198964 ] |
Fr, 04 Februar 2005 19:46 |
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In message <42035EC1.A4F3E96B [at] me.freeserve.com>, Allan Gould
<allang [at] me.freeserve.com> writes
>
>I did a quick check on the Validation and it came back with the correct
>results when I entered true details and false details
<Devils advocate mode on> How could you be SURE they were false details?
In other words, you could input details that weren't your which could
have been valid for somebody else.
--
John Boyle
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| Re: Account number verification. [message #198966 ] |
Fr, 04 Februar 2005 20:21 |
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> Allan Gould wrote
> >I did a quick check on the Validation and it came back with
> >the correct results when I entered true details and false details
>
"john boyle" wrote
> <Devils advocate mode on>
> How could you be SURE they were false details?
> In other words, you could input details that weren't
> your which could have been valid for somebody else.
Perhaps an old account of his which he's now closed?
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| Re: Account number verification. [message #198967 ] |
Fr, 04 Februar 2005 20:32 |
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In message <cu0hv0$h6r$1 [at] sparta.btinternet.com>, Tim <me [at] home.uk> writes
>> Allan Gould wrote
>> >I did a quick check on the Validation and it came back with
>> >the correct results when I entered true details and false details
>>
>"john boyle" wrote
>> <Devils advocate mode on>
>> How could you be SURE they were false details?
>> In other words, you could input details that weren't
>> your which could have been valid for somebody else.
>
>Perhaps an old account of his which he's now closed?
AIUI, it doesnt validate the existence of an account ar attribute a
particular sort code and account number to an individual, just that the
account number is a member of the set of valid account numbers that
could exist.
(This is just my theory and I am quite willing for to be disproved).!!
--
John Boyle
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| Re: Account number verification. [message #198970 ] |
Fr, 04 Februar 2005 21:11 |
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"BigMomma" <bigmomma [at] mommaisbig.co.uk> wrote in message
news:ctutin$4pa$1 [at] news6.svr.pol.co.uk...
> Sort codes can be checked for accuracy, but what about account numbers
> at UK banks.
>
> I ask because I signed up to ebay today and they needed a sort code and
> account number. What if someone gave a real sort code but made up the
> account number. Could the number be checked; whether the specific
> number itself or the algorithm?
We use software like this:
http://www.eiger.co.uk/htmlfiles/bankwizardint.html
It's updated with a regular feed of information from the banks. Not a
complete list of accounts, but details of which ranges of accounts are
associated with which sort codes, etc.
--
Smorgo (Steve Morgan)
Hello: '01 VFR 800 FI, '86 V8 110
Goodbye: '01 NT650V
E-Mail address is spam-trapped. Use my first name at wormpurple dot com
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| Re: Account number verification. [message #198976 ] |
Sa, 05 Februar 2005 02:30 |
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john boyle wrote:
> AIUI, it doesnt validate the existence of an account ar attribute a
> particular sort code and account number to an individual, just that
the
> account number is a member of the set of valid account numbers that
> could exist.
I don't know, I've tried putting my own account number with one digit
wrong and it tells me it's invalid, presumably that would be within a
range of account numbers? I thought the site might be using the Luhn 10
formula, my sort code together with my account number at one bank does
match the Luhn 10 formula as its part of my switch card number. I
thought by entering a false account number that matches Luhn 10 it
would say it was valid but it doesn't. Unless theres some formula or
method I don't know about, I think the site must have some real time
way of checking if an account number is valid or not.
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| Re: Account number verification. [message #199042 ] |
So, 06 Februar 2005 00:22 |
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On 4 Feb 2005 17:30:33 -0800, "Marx Peterson" <marxpeterson [at] yahoo.com>
wrote:
>john boyle wrote:
>> AIUI, it doesnt validate the existence of an account ar attribute a
>> particular sort code and account number to an individual, just that
>the
>> account number is a member of the set of valid account numbers that
>> could exist.
>
>I don't know, I've tried putting my own account number with one digit
>wrong and it tells me it's invalid, presumably that would be within a
>range of account numbers? I thought the site might be using the Luhn 10
>formula, my sort code together with my account number at one bank does
>match the Luhn 10 formula as its part of my switch card number. I
>thought by entering a false account number that matches Luhn 10 it
>would say it was valid but it doesn't. Unless theres some formula or
>method I don't know about, I think the site must have some real time
>way of checking if an account number is valid or not.
They use a modulus 10 or modulus 11 check. A 6 digit number (for
example 113558) is made into a 7 digit number by inserting one
additional "check" digit, usually at the end or beginning. The check
digit is calculated by applying a formula (or using a table) to each
of the original 6 digits, one at a time, resulting in 6 new
(temporary) numbers. The temporary numbers are (usually) added
together and their sum is subtracted from the next highest multiple of
10. So, a sum of 57 would be subtracted from 60 and the check digit
would be 3. The final account number would then become 1135583.
Modulus 10 checks give you a 90% chance of picking up a single keying
error (including number reversal) so some still slip through. Modulus
11 checks are better. Some Banks add a check digit to both ends of the
account number - one based on the original (say 6 digit) account
number itself and the other based on the new 7 digit account number
*and* the sort code, so you end up with an 8 digit (or more) account
number. That method gives Banks a pretty good chance of quickly
spotting keying errors or "made up" account numbers.
Account number range and other checks are done by the Banks themselves
but these would only be of use to outsiders if the Banks chose to
publish the ranges, unused account numbers etc., which I don't think
they do. Hope that helps.
--
Dave
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| Re: Account number verification. [message #199048 ] |
So, 06 Februar 2005 02:27 |
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In message <1107567033.954644.86610 [at] g14g2000cwa.googlegroups.com>, Marx
Peterson <marxpeterson [at] yahoo.com> writes
>john boyle wrote:
>> AIUI, it doesnt validate the existence of an account ar attribute a
>> particular sort code and account number to an individual, just that
>the
>> account number is a member of the set of valid account numbers that
>> could exist.
>
>I don't know, I've tried putting my own account number with one digit
>wrong and it tells me it's invalid, presumably that would be within a
>range of account numbers? I thought the site might be using the Luhn 10
>formula, my sort code together with my account number at one bank does
>match the Luhn 10 formula as its part of my switch card number. I
>thought by entering a false account number that matches Luhn 10 it
>would say it was valid but it doesn't. Unless theres some formula or
>method I don't know about, I think the site must have some real time
>way of checking if an account number is valid or not.
>
I dot know what Luhn is but is it based on a modulus check? In any event
you are checking a card number, which is not the same as an account
number check because cards carry more digits than the basic sort code &
account number (6+8).
Bank account numbers are made up of 8 digits (although one well known
bank suppresses a digit) the first few of which are used as various
identifiers by the bank, e.g. if the 3rd digit was a 9 for one very well
known high street bank this meant it was a staff members account.
The whole account number had to satisfy a modulus check so that, in the
old days, when the account numbers were being input by a clerk on a
mechanical punched tape machine, the machine could spot an account
number as being not a member of the set of feasible account numbers.
Different branches had different moduli.
Also, the first digit was a 'balancing' number, but dot ask me how this
worked.
All of this meant that account numbers weren't sequential, there would
be irregular gaps in the run of numbers.
So, in summary, and having done some more research since my original
post, AFAICS, those online sites DONT perform an account specific check,
just a 'is it possible' type check.
--
John Boyle
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