> ## Documentation Index > Fetch the complete documentation index at: https://docs.e-invoice.be/llms.txt > Use this file to discover all available pages before exploring further. # Glossary > Find the definition of each Peppol, e-invoicing and e-invoice.be term that this documentation uses. Each entry gives a short definition and a link to the page that uses the term. ## Peppol network ### Peppol An international network for the exchange of electronic business documents. Each participant connects through an access point, and participants on different access points can exchange documents. See [Introduction](/index). ### Access Point A service provider that sends and receives documents on the Peppol network for its customers. e-invoice.be is an access point. See [Introduction](/index). ### SMP Service Metadata Publisher. A registry that holds, for each participant, the document types that the participant can receive and the access point that receives them. e-invoice.be operates an SMP. See [Look up Peppol participants](/guides/lookup-participants). ### SML Service Metadata Locator. The central DNS-based service of Peppol that tells a sender which SMP holds the data of a participant. See [Admin API](/admin-api#peppol-registration). ### Peppol Directory A public, searchable index of Peppol participants. It is built from the business cards that the SMPs publish. See [Look up Peppol participants](/guides/lookup-participants). ### Business card The public company data (for example name and country) that an SMP publishes for a participant. `GET /api/validate/peppol-id` returns `business_card_valid` and, when available, `business_card`. See [Look up Peppol participants](/guides/lookup-participants). ### Peppol ID The address of a participant on the Peppol network. It is also called participant ID. The format is `scheme:identifier`, for example `0208:1018265814`. See [Look up Peppol participants](/guides/lookup-participants). ### Scheme The four-digit code in front of a Peppol ID that tells which register issued the identifier. It is also called ICD (International Code Designator). Belgian companies use `0208`. See [Look up Peppol participants](/guides/lookup-participants). ### Peppol registration The publication of a Peppol ID on an SMP, so that the participant can receive documents. A company that only sends documents does not need a registration. See [Admin API](/admin-api#peppol-registration). ## Company identifiers ### VAT number The tax identifier of a company, with a country prefix, for example `BE1018265814`. In the API it is `vendor_tax_id` and `customer_tax_id`. In Belgium the Dutch name is "btw-nummer" (BTW). See [Create e-invoices](/guides/creating-invoices). ### Enterprise number The company registration number. In the API it is `vendor_company_id` and `customer_company_id`. For a Belgian company it is the CBE number: the ten digits of the VAT number without the `BE` prefix. See [Create e-invoices](/guides/creating-invoices). ### CBE and KBO The Belgian company register. CBE (Crossroads Bank for Enterprises) is the English name and KBO (Kruispuntbank van Ondernemingen) is the Dutch name. The CBE number with scheme `0208` is the Peppol ID of a Belgian company. See [Look up Peppol participants](/guides/lookup-participants). ## Standards and formats ### EN 16931 The European standard that defines the data model of an electronic invoice. See [Validation during development](/guides/validation). ### UBL Universal Business Language. An XML format for business documents. Peppol invoices and credit notes are UBL documents. The API converts JSON to UBL. See [Send UBL documents](/guides/ubl-documents). ### BIS Billing 3.0 The Peppol specification for invoices and credit notes. It applies EN 16931 to UBL and adds Peppol rules. Each document that the API sends must comply with it. See [Validation during development](/guides/validation). ### Schematron A rule language for XML documents. The rules of EN 16931 and BIS Billing 3.0 are published as Schematron rules, and validation reports a failure with the identifier of the rule. See [Validation during development](/guides/validation). ### Tax category code A code from the code list UNCL5305 that gives the VAT treatment of a line or a tax subtotal, for example `S` (standard rate), `Z` (zero rate), `E` (exempt) and `AE` (reverse charge). See [LineItem schema](/api-reference/schemas/line-item). ### VATEX The code list for VAT exemption reasons. A VATEX code tells why no VAT is charged. See [Invoice totals and calculations](/guides/invoice-totals). ### Unit code A code from UN/ECE Recommendation 20 that gives the unit of measure of a line quantity, for example `C62` (one, piece) and `HUR` (hour). See [LineItem schema](/api-reference/schemas/line-item). ## Document types ### Invoice A request for payment from a vendor to a customer. See [Create e-invoices](/guides/creating-invoices). ### Credit note A document that cancels or decreases an invoice. See [Create credit notes](/guides/credit-notes). ### Self-billing A procedure in which the customer issues the invoice or credit note for the vendor. The customer is then the sender of the document on Peppol. See [Self-billing and debit notes](/guides/self-billing). ### Document state The position of a document in its lifecycle: `DRAFT`, `TRANSIT`, `SENT`, `FAILED` or `RECEIVED`. See [Document lifecycle and delivery tracking](/guides/document-lifecycle). ## e-invoice.be terms ### Company The account unit in the app and in the guides. A company has its own API key, Peppol IDs, documents and webhooks. See [Authentication](/authentication). ### Tenant The name of a company in the Admin API and in the reseller pages. A tenant is a company that a [reseller](/reseller-programme) manages. The webhook payload field `tenant_id` identifies the company. See [Admin API](/admin-api#tenant-management). ### Organisation API key The API key of a reseller. It gives access to the Admin API and to all tenants of the reseller. It is different from the API key of one company. See [Admin API](/admin-api#authentication). ### Test mode The mode of a company that has no connection to the Peppol network. Outbound documents go to email and inbound documents are simulated. Test mode is fixed when the company is created. See [Test mode and sandbox companies](/environments#test-mode). ### Sandbox company A company in test mode. Use it for development and tests. A sandbox company cannot be converted into a production company. See [Test mode and sandbox companies](/environments#sandbox-companies). ### Production company A company that sends and receives documents on the Peppol network. See [Go-live checklist](/going-live). ### Simulate inbound The function that puts a document into the inbox of a sandbox company, as if it was received from Peppol. See [Testing received documents](/environments#testing-received-documents). ### Send-only tenant A tenant that sends documents on Peppol and has no Peppol registration through e-invoice.be. See [Admin API](/admin-api#send-only-tenants). ### Mailbox The record of the emails that are sent to the `@outbox.email.e-invoice.be` address of a company. e-invoice.be makes a draft document from the attachment of each email. The Mailbox endpoints list the emails, give access to their attachments and retry a failed email. See [Send invoices by email (Mailbox)](/guides/mailbox). ### Webhook An HTTP request that e-invoice.be sends to your server when a document event occurs. See [Webhooks](/essentials/webhooks). ## Next Steps Send a first document from a sandbox company Find and check Peppol IDs Check a document against the BIS Billing 3.0 rules Move from a sandbox company to a production company