If your document expires after you've added it to your Yoti, you can replace it with a new version.
First, go to the My Yoti Tab. Next, click on ID Documents, and then Add ID Document, and Select Country. You can then choose the relevant document type.
If your document expires and you do not update it, you can still use your Yoti. However, there may be some limitations to what you can use it for. For example, you will not be able to open a new bank account without a valid document.