Money received in advance from shareholders before it is actually called-up by the directors is :

When a shareholder pays a portion or all of the uncalled capital advance early, it represents a liability for the company until the call is officially made. The journal entry passed to record this receipt is:
$$\text{Bank A/c}\text{Dr.}$$
$$\text{To Calls-in-Advance A/c}$$
Hence, the money is credited to the calls in advance account.