Different banks have given me same customer ID

JudgeDekker

Hello. I have opened a few online easy access savings accounts over the years with banks such as Marcus, Tesco's, Virgin, Wyeland etc. Typically I open one, then switch to a new one when the bonus rate runs out. Recently I noticed the the Customer ID I have just been given from one bank has the same first 6 characters as the Customer ID I was given by another. I checked, and actually FOUR banks have given me customer IDs with the same first 6 characters. Four completely different institutions, not part of the same banking group.

How can this be, please? It surely can't be a coincidence. Could it be that they all outsource the process of generating a customer ID to the same provider, and that provider has an algorithm based on my name and address for the first few digits? Or is there hacking going on? Should I be worried? Thanks

[Deleted User]

There's obviously no hacking going on. Banks don't spend their time hacking other banks' customer ID systems.

It could be either be a coincidence, or it could be that the first part of relatively generic, or similar/same systems used across the providers.

Certainly nothing to be worried about.

eskbanker

I believe there's some sharing of backend systems by multiple smaller providers, which leads to customer IDs in similar formats - if I recall correctly there's a common system used by Newcastle and West Brom building societies and Charter Savings Bank among others, maybe Birmingham Midshires too. Which ones are you referring to?

edgex

Are they variations on your name?

RG2015

Just out of interest, which were the four banks?

JudgeDekker

I'd be particularly interested to hear if this has happened to anyone else. Thanks.

[Deleted User]

We’d particularly like to hear some examples and the names of the banks

Tom99

Yes I have the same NatWest/Kent Reliance etc.

Its my DOB - DDMMYYxxxx

JudgeDekker

The four banks that I noticed it for are Chartered Savings, Bradford and Bingley, Ford Money and Wyeland. The customer ID in each case is a 'random' string of 10 characters. Except that it appears to not be random, because five of the first six characters are the same for all four.

The only thing I can think of is that they all use the same software to generate a Customer ID, and that part of the string generated is based on your name or National insurance number or something. But if that's the case I would have thought this would be a known thing, but I didn't find any mention of it by googling.

eskbanker

JudgeDekker wrote: »

The four banks that I noticed it for are Chartered Savings, Bradford and Bingley, Ford Money and Wyeland. The customer ID in each case is a 'random' string of 10 characters. Except that it appears to not be random, because five of the first six characters are the same for all four.

The only thing I can think of is that they all use the same software to generate a Customer ID, and that part of the string generated is based on your name or National insurance number or something. But if that's the case I would have thought this would be a known thing, but I didn't find any mention of it by googling.

I'm even more convinced now that this is the result of the use of a shared underlying system by these providers, and have it in the back of my mind that it's associated with Newcastle Building Society but can't remember where I saw that (on an old thread on here somewhere).

I have also had accounts with three of these and remember the same customer ID format applying for each, with at least the first three characters being the same - I don't know about the algorithm used to derive these IDs from customer-specific data but wouldn't expect this to be widely publicised (for obvious reasons!) and don't see it as suspicious in any way....

Edit: Found the old thread (from 2011): https://forums.moneysavingexpert.com/discussion/comment/40054196#Comment_40054196

I think the shared system may be called OFIS, as this appears in various URLs used by the institutions concerned, including Ford Money, West Brom, Bradford & Bingley, etc, as you'll see if you search the forum using this term.

sal_III

Does it really matter if they use the same provider/software on the backend or the same algorithm? Ultimately you have unique IDs for each of them.

It's most likely a hash of your name, DoB or NINo which is common practice.

The same way you usually get FirstName.LastName@Company.com work e-mail address. It's not a grand conspiracy or hacking...