Authentication (API key)
Számla Agent requests must be authenticated. You can use either an Agent key (recommended) or a username and password (the latter is only recommended for self-billing / invoicing on behalf of others).
Recommended: Agent key
We recommend using an Agent key instead of a username and password. Use the <szamlaagentkulcs> tag in your XML. (Self-billing and invoicing on behalf of a third party are exceptions.)
To generate an Agent key, the owner or administrator of the account needs to log in to the Számlázz.hu website and scroll down to the bottom of the dashboard. There is a section called Számla Agent kulcsok (= Számla Agent Keys). Click the key icon on the right side to generate a key. The key is generated immediately and is ready to use. You can copy it by clicking the icon next to it.

Provide the key in the <szamlaagentkulcs> tag. You can also supply the key in the <felhasznalo> and <jelszo> tags if you use an old webshop that cannot use <szamlaagentkulcs> (both tags should contain the same key).
The key is for API use only; you cannot log in to the Számlázz.hu website with it. The system accepts the key only in lowercase – if you send it with uppercase letters, authentication may fail.
Alternative: username and password
In Számlázz.hu, multiple users can access a single company. You can create a separate user specifically for Számla Agent with billing permissions only. The e-mail address for this user should be monitored by people who can act on errors, as error messages are sent to that address. The user used for Számla Agent must have access to a single invoicing account only – for multiple companies you need a separate user per company, otherwise you will get an error.