Are there any costs and fees for adding, holding or withdrawing money from the “Cash with fixed interest” section?

There are no fees for adding, holding, or withdrawing money from the Interest Rate Pocket’s “Cash with fixed interest” section.

With the Interest Rate Pocket, you won't be charged any account management fees for additional Money Pockets regardless of whether you are on the Prime, Plus, or Standard plan.

To learn about costs of Money Market Funds, read this article.