Defaults for new items, the units and decimals every item is measured in, and the two settings that decide how rate lists behave.
Item preferences decide what a new item starts out as, so you fill in less on the form every time. Two of them change more than a default: whether the item form opens in variants mode, and whether rate lists apply per document or per line.
Settings
Go to Settings›Finance›Items.
Items settings. The Defaults section decides what a new item starts out as.
Defaults
Preference
What it does
Worth changing when
Create new items as services
New items open with Type set to Service instead of Goods.
You sell mostly labour rather than stock.
Create new items with variants
The item form opens in variants mode rather than as a single item.
Most of your catalogue comes in sizes or grades.
Allow duplicate item names
Chooses what an import matches on. It does not gate saving an item.
Your SKUs are complete and you want imports keyed on them.
General
Preference
What it does
Worth changing when
Quantity decimal places
How many decimals a quantity accepts, up to the three that are stored.
You sell by weight or length rather than by the each.
Dimension unit
The unit item dimensions are measured in.
Your catalogue is specified in inches rather than centimetres.
Weight unit
The unit item weights are measured in.
Your carrier bills in pounds rather than kilograms.
Barcode scan field
Which field a scanner types into when it reads a code.
Your labels carry the SKU rather than a separate barcode.
Inventory defaults
Preference
What it does
Worth changing when
Default valuation method
Pre-selected on new tracked items.
You have standardised on one method across the catalogue.
Default inventory account
The stock account new tracked items post to.
Stock sits in one account for everything you hold.
Rate lists
Preference
What it does
Worth changing when
Enable rate lists
Turns the rate list field on across sales documents.
You price the same item differently for different customers.
Apply rate list at line item level
Lets a single line take a different rate list from the rest of the document.
One order genuinely mixes contract and standard pricing.
Update selling price when a quote is sent
Writes a quote's edited price back onto the item as its new selling price.