Custom fields
Custom fields let you attach your own attributes to Kontier records: an internal account code on a customer, a contract reference on a subscription, a cost centre on an invoice.
What they are for
Keeping your identifiers next to the record they describe, so a webhook payload or an export already carries what your systems need to match on. Without them you maintain a mapping table, and mapping tables drift.
What they are not for
Custom fields are storage, not behaviour. Nothing in Kontier reads them to decide anything: they do not affect pricing, tax, dunning or document templates.
If you want a value to change what is charged, it needs to be real configuration rather than a custom field. Pricing is decided by prices, tax by tax rules.
Do not put secrets in custom fields
They are readable by anyone who can read the record, they appear in exports and webhook payloads, and they are not encrypted at the field level.
Reference
| Topic | When you need it |
|---|---|
| Customers | The most common place to attach one |
| Webhooks and events | Where custom fields show up downstream |
| Accounting export | Carrying your codes into finance |