# Line item and unit code problems

Every e-invoice line needs enough structured information for the recipient system to understand what was sold and how the amount was calculated.

## What you may see

- Item name is required
- Invoiced quantity is required
- Unit of measure is required
- Unit code is not in the standard list
- Line extension amount is required
- Price amount must be non-negative
- Calculated line amount does not match
- Line service period end date is before start date

## What this means

Every e-invoice line needs enough structured information for the recipient system to understand what was sold and how the amount was calculated.

## What to check

- Description or item name
- Quantity
- Unit of measure
- Unit price
- Net line amount
- VAT category and rate
- Service period, if the line covers a period