National insurance number requested from some banks but not others

Andrew1974

I smell tuna fish here. Why are posts being made by ARCHIVED USER?

Ergates

The NINO, being external and consistent, can be very useful to help a bank correctly identify and link customers *within" their own systems. They don't need to verify the NINO against some external system to do this.

It is usually the case that a banks different systems were all built (or bought in) at different times, over the course of many years. One result of this is that they all hold customer name/address data slightly differently. This means that when a customer holds multiple different accounts within the same bank, it can be hard to accurately link them together. For instance, is the "Mr John Smith" in the current accounts system the same as the "John H Smith" in the ISA system? And what about the "J Smith" in the loans system? Even if the addresses match can you be 100% sure - they might be father and son.

Banks spend lots of time and money on complicated fuzzy matching systems to try to get around this, but they're still only 100% accurate.

Adding an external and consistent ID with the account information can be a big help. J Smith with NINO AB123456C is almost certainly the same as John Smith with NINO AB123456C.