There is no need to “close” the year in Swipe. You can simply use the date filter to view data from any specific time period, including previous year.
To begin invoicing from serial number 1 for the new financial year, you can add a new prefix.
Please refer to the below mentioned article/video to change the Prefix:
Article - https://community.getswipe.in/t/how-to-add-prefixes-for-current-financial-year-25-26-on-web/2106
Video - https://youtu.be/oNij2nYTQ7E