| UUID | uuid | string | | Universally Unique Identifier. |
| Index | i | integer | | Line number inside the list of charges (calculated). |
| Key | key | cbc.Key | | Key for grouping or identifying charges for tax purposes. A suggested list of keys is provided, but these may be extended by the issuer. |
| Code | code | cbc.Code | | Code to used to refer to the this charge by the issuer |
| Reason | reason | string | | Text description as to why the charge was applied |
| Base | base | num.Amount | | Base represents the value used as a base for percent calculations instead of the invoice’s sum of lines. |
| Percent | percent | num.Percentage | | Percentage to apply to the sum of all lines |
| Amount | amount | num.Amount | | Amount to apply (calculated if percent present) |
| Taxes | taxes | tax.Set | | List of taxes to apply to the charge |
| Extensions | ext | tax.Extensions | | Extension codes that apply to the charge |
| Meta | meta | cbc.Meta | | Additional semi-structured information. |
