Every cost is associated to a supplier. For example, if you bought Furniture at IKEA, then IKEA is your supplier. Your water (and the water bill) are provided by Hidralia (for example).
From some suppliers, you always get the same service offered. For example Avatel (and internet provider) will send you monthly bills and they will always be about your internet connection.
That’s why we introduced default ledgers. When adding a supplier, you can now select an appropriate ledger. See the example below, where the ledger Utilities is set for the supplier Hidralia.

If you have selected a default ledger for a supplier and start adding invoices from that supplier to your account, the ledger you attached to that supplier will automatically be selected. It saves a lot of time when entering invoice data.

If you want to fast-track your invoice adding, start using default ledgers for suppliers. They will save you a lot of time when processing all costs for your property.