An ISIN (International Securities Identification Number) uniquely identifies a security and is universally recognizable. ISINs are used for numerous reasons including clearing and settlement. Some banks allow their investor clients to invest in a range of securities, e.g. a hedge fund, directly, via an ISIN code.
The process is:
The investor orders its bank to subscribe to the fund and provides its bank with the ISIN number and or name of the fund.
The bank, acting as a nominee, subscribes on behalf of the investor and signs a subscription agreement which is processed by the fund's administrator.
The bank withdraws the amount of the subscription from the investor's bank account and wires the corresponding amount to the bank account of the fund.
The nominee bank then books the position on the investor's security portfolio.
The benefits are:
An investor can see the value of their investment on their account statement.
Their bank handles the majority of the process for them and they're not required to personally sign a subscription agreement or provide KYC documents.
If the fund is performing well, a private banker might also recommend it to some of their other clients who have similar profiles.