---
updatedAt: 2025-11-06T07:01:58.000Z
agentTools:
  projectIndex: https://docs.billit.be/llms.txt
---

# Header values

What you can put in the header information of the API

# To Billit

Below you can find all accepted header values that have a usage with the API

| Header Name         | Header Value                     | Header Usage                                                                                                                                                     |
| :------------------ | :------------------------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| PartyID             | INT - A party ID                 | To define the context, the ID of your company.  When you use multiple companies, then make sure that in the header of your API the correct company is addressed. |
| ContextPartyID      | INT - A party ID                 | To combine when you are using application as an accountant                                                                                                       |
| ApiKey              | "Secret ID'                      | To be authenticated with the API                                                                                                                                 |
| Authorization       | "Access token"                   | To be authenticated with the API                                                                                                                                 |
| Idempotent-Key      | "Unique client generated string" | To make unique requests                                                                                                                                          |
| StrictTransportType | "true"                           | To make transportTypes strict (no fallback to alternative method if the primary method is not available)                                                         |

# From Billit

| Header Name      | Header Value             | Header Usage          |
| :--------------- | :----------------------- | :-------------------- |
| Billit-Signature | String (Time +Encrypted) | To verify the webhook |