Your situation is not clear. Are you keeping the books of this client as an accountant or bookkeeper? Or is the client your customer, buying a subscription for something from your organization?
My answers assume the client is a customer of your organization and is buying the subscription from you.
If you are using accrual basis accounting, you first need to consider the terms of the subscription. If the customer has, for example, purchased a one-year, non-cancellable magazine subscription and is owed delivery of all issues as they come out, you might consider the full amount as having been earned when invoiced. You would not split the income by year in that case. But if they have subscribed to some service that can be cancelled, and for which you would be liable to refund the undelivered portion, the sales invoice needs to be split into two line items, one posted to a current income account and the other to a liability account for prepaid items. During the future accounting period, use a journal entry to transfer the appropriate amount from the prepaid liability account to the income account. The receipt from the customer in payment of your sales invoice does not enter the picture. There could be situations in between, as well.
If you are using cash basis accounting, the concept of splitting income recognition into different accounting periods does not apply. So there is no need for multiple line items on the sales invoice and no journal entry, regardless of the subscription terms. The income is earned when received.