In your list of jobs, clients, suppliers, quotes, expenses and invoices, you can pin items to make sure they appear the top of your list. For this, simply click on the three dots at the end of the line and select 'Pin'.
After selecting this option and refreshing the page, the line will turn yellow and move up in your list.
To unpin an item, click again on the three dots and select 'Unpin' (and refresh the page).
Note that when you pin a client at the top of your list, this client will appear first in all dropdown menus in LSP.expert (e.g. when you select the client when creating a new job).
