This depends on the range of products and suppliers you use and if this data is already available in Once format or spreadsheets. Some customers have got up and running after just a few hours, for others it can take several days. 

Once is delivered with just a small example catalogue of products and prices. When you first sign up for Once we discuss with you what data you need and what we can deliver from our ever-growing list of supplier data available in Once format. Our support team will assist in building your catalogue and give full training for how you can add and edit your own data.  We also offer paid services for catalogue builds if you don't have the time or resources.

It is not essential that you have all your products or prices included as you can easily type any missing data on the app. Many users only include their most commonly sold items.