Account # on letter or not?

continualdiamond

Im currently writing a letter to my bank regarding being overdrawn and seeing if the fee they charge can be waived as haven't been overdrawn in 3 years.

Anyway, should i put my bank account # at the top of the letter so they know which customer is sending the letter or for security reasons is it not a good idea?

oldagetraveller

They usually state somewhere to quote your account number in all correspondence. Don't see how it can be a security issue as your account number plus sort code, is printed on cheques and other bits of personal banking paperwork which others could see.

oldwiring

I wonder if the security asoect may show a litlle paranoia. In my time, now long past- in a bank, I have seen elevated spheres caused by muddles with names- things like farher and som habing the same intials or even name. The account number gives far more positive identifiacation, and, moreover, is mathematically constructed , so that keying errors result in rejection. For me it's the account number and sort code every time

oldwiring

Al_Mac wrote:

Even more fun, father and son with same name and a joint account

:rotfl: :rotfl: :rotfl:

I think you have sadistic tendencies!

magyar

oldwiring wrote:

I wonder if the security asoect may show a litlle paranoia. In my time, now long past- in a bank, I have seen elevated spheres caused by muddles with names- things like farher and som habing the same intials or even name. The account number gives far more positive identifiacation, and, moreover, is mathematically constructed , so that keying errors result in rejection. For me it's the account number and sort code every time

I have to say I didn't know that! Do you mean if I get one digit wrong or something there's an algorithm it uses to check it's right?

oldwiring

My bank does a modulus 11 check on the account no ( or part) and a modulus 10 check on the sort code and account number together. The two checks together make it extremely hard to make a muck up. Freqently modulus checks rely on prime nos. e.g 23 97.

Mikeyorks

magyar wrote:

I have to say I didn't know that! Do you mean if I get one digit wrong or something there's an algorithm it uses to check it's right?

No - there's an 'algorithm' to check it's wrong ..... so there's less likelihood of it going to someone elses account if one digit is wrong or there's transposition.

The modulus checks (there's many variants) were put in place when all references were 'data captured' by keying. So it's also a mechanism to protect against high speed data entry operators transposing stuff. Less logical reason for check digit protection now - as most bulk capture is done by Optical / Intelligent Character Recognition. But as repair work is still done by data operators / and people still write them - it's a discipline that thankfully persists on most key references.

Gosh - quite taken me back to my programming days:rolleyes:

magyar

Thanks all! I'm afraid I don't have the slightest idea what you're all on about but it all sounds very clever...

Mikeyorks

It's one of those background security checks that most people are unaware of. There's a fairly basic explanation here of one of the simpler modulus. The check digit can be anywhere in the reference - it doesn't need to be at the end - but it has to be to a standard everyone who needs to validate it understands.

It's deployed on all sorts of references (Bank accounts / ISBNs / bar codes / Credit Cards / Gas & Elec refs / HMRC refs etc etc) - to minimise errors caused by people getting a digit wrong / transposing figures - or writing a figure indistinctly on a paying in slip.

http://www.school-resources.co.uk/checkdigit.htm

oldwiring

I will give an example of the system used by my bank for ordinary accounts. The numbers quoted are fictitious.
The account number allocated has 7 digits with the last one being the check.
The first digit is multiplied by 7, the second by 6 and so on until the last which is multiplied by 1. Let the first 6 digits be 2 3 4 5 6 7. Applying the respective multipliers to each digit gives 14 18 20 20 18 14. The sum of these is 104. As the next number above 104 that is divisible by 11 (see my earlier post and reference to modulus 11), the required check digit is 6 (110-104). I tell you it’s very hard indeed to make a keying error, especially transpositions - the most common, and have the same check digit. Subsequently the account numbers were insufficient and were extended to 8 digits by adding the new one to the front. For this post we’ll say the new digit is 7. The sequence is 7 2 3 4 5 6 7 and then 6 (the old check digit). Assume the sort code to be 5 0 5 5 3 2 and then take all 14 digits. Multiply every other number by 2 the first by 2, the second by 1 and so on. If any resulting number is over 10, add that number’s digits together (e.g. 15 =6). If the sum of the new sequence is a multiple of 10 it passes. The sum in my example is 50. It passes the second test.

I think you will agree that the two tests together reduce greatly the chance of error.