> ## Documentation Index > Fetch the complete documentation index at: https://docs.lastaccountingcompany.com/llms.txt > Use this file to discover all available pages before exploring further. # Send an e-invoice > Issues a `maventa_einvoice` draft and transmits it over the e-invoice network: allocates the invoice number, stores the invoice, books the sale when LAC keeps the ledger, and queues the Finvoice send. For a partner-profile draft, the tenant's Maventa connection is only the material-handler transport: the partner stays the Finvoice seller and payment beneficiary, receives a bookkeeping PDF copy, and the invoice has no tenant ledger effect. The e-invoice network is the only buyer-delivery channel LAC transmits on. A partner-profile send also emails its seller a bookkeeping copy. Drafts on any other channel are refused with 409; `pdf_download` drafts are issued through `POST /invoices/{invoice_id}/finalize` instead. Requires a write-scoped key. ## OpenAPI ````yaml /openapi.yaml post /invoices/{invoice_id}/send openapi: 3.1.0 info: title: LAC Customer API version: '2026-07-15' description: > Last Accounting Company (LAC) is an AI-native accounting firm for Finnish SMBs: continuous reconciliation, daily close, real-time dashboards, and full Vero reporting. This API is the same surface the LAC customer portal UI uses. It gives you programmatic access to your books (read-only general-ledger views), financial statements, documents, invoicing, payroll, source-system connections, and the message channel to Björn, the accounting agent. ## Authentication Every request carries `Authorization: Bearer `. Two token kinds are accepted: - **Portal API key** (`lac_sk_...`) — minted in portal Settings → API access. Keys have a scope of `read` or `write`. Read-scoped keys are refused on all mutating methods (POST/PATCH/DELETE). Write-scoped keys act as the `operator` role: they can never use payroll endpoints (reads included), change company settings, grant access, approve or return an invoice, or manage API keys. Payroll and company settings require an interactive admin or existing broad approver. Invoice decisions require the matching invoice review permission. Write-scoped keys can prepare draft partner seller profiles. An interactive company admin must review the evidence and activate a profile or change an active profile. - **Firebase ID token** — the interactive session token used by the portal UI itself. API keys are pinned to a single company, so the `customer_id` parameter (query string on GETs, body field on writes) can always be omitted when authenticating with an API key. Interactive tokens with access to multiple companies use `customer_id` to select one. ## Conventions - All field names are `snake_case` on the wire. - Monetary amounts are **integer cents** (fields suffixed `_cents`). - Rates and percentages are **basis points** (fields suffixed `_basis_points`; 10000 = 100%, e.g. Finnish standard VAT 25.5% = 2550). - Quantities on invoice lines are decimal strings (e.g. `"1"`, `"2.5"`). - Dates are `YYYY-MM-DD`; periods are `YYYY-MM`; ranges accept `YYYY-MM`, `YYYY-Qn`, `YYYY`, `all`, `this_month`, or `last_6_months`. ## Limits - Document uploads: at most 20 files and 25 MB per request. - Sheet pagination: `limit` is capped at 200 rows per page (0 = unpaginated). ## Errors Errors return a JSON envelope `{"error": "...", "detail": "..."}` with a conventional HTTP status code (401 missing/invalid token, 403 insufficient scope or role, 404 not found, 422 validation failure). More at [docs.lastaccountingcompany.com](https://docs.lastaccountingcompany.com). contact: name: Last Accounting Company url: https://docs.lastaccountingcompany.com servers: - url: https://api.app.lastaccountingcompany.com/portal description: Production (note the /portal base path). security: - apiKey: [] tags: - name: Company description: Company profile, identity, overview, and agent status. - name: Onboarding description: Saved customer onboarding facts, source inventory, and opening statements. - name: Books description: >- Read-only windows into the canonical general ledger: the spreadsheet-style Books/VAT sheet, financial statements, and analytics. There is no cell-edit or batch-edit API — the books are maintained by LAC. The one write here is a row declaration: your answer about a row (no receipt exists, private, a split, or a different booking), recorded as evidence for Björn. - name: Dimensions description: >- Project, cost-centre, department, and customer-defined reporting lenses over posted general-ledger lines. Provider catalogs are read-only; local axes and values are available for bank/file-only books. - name: Documents description: Receipt/invoice/contract uploads and per-file ingest metadata. - name: Messages description: The chat channel to Björn, the accounting agent. - name: Work log description: >- Append-only work-hours log (date, minutes, note). Hours are records for invoicing and payroll evidence; they do not post to the books. Kilometres are not logged here — vehicle travel is submitted as an expense claim in the portal, where statutory reimbursement rates apply. - name: Filings description: Filing authorization, review requests, and produced output packages. - name: Invoicing description: >- Sales invoicing — drafts, partner seller profiles, e-invoice sending, PDF finalizing, credit notes, reminders, recurring templates, and the invoice-customer register. LAC sends buyer invoices on the e-invoice network only. A partner-profile invoice also sends its legal seller a bookkeeping PDF copy. - name: Payroll description: >- Payroll workspace — employees, tax cards, employer settings, draft runs, and payslips. Every payroll operation (reads included) requires an interactive admin or existing broad-approver session and is NOT available to API keys. - name: Payments description: >- Contextual review and named-human release for source-bound purchase, payroll, and reimbursement payments. There is no manual payment composer and no bank file: a batch that cannot be delivered directly to the bank fails closed rather than becoming the customer's manual task. - name: Connections description: >- Source-system connections (bank, settlement providers, commerce, accounting systems, inbox/Gmail, Google Sheets) and service-connection requests/confirmations. PayPal consent can start through this API and returns a URL that a company admin must open. Other browser-interactive consent flows remain portal-only. - name: Imports description: Historical import runs (e.g. migrated books) and their artifacts. - name: API keys description: >- Manage portal API keys. These endpoints require an interactive admin session (Firebase token) and are NOT available to API-key bearers, which receive 403. - name: Lens description: >- Typed, display-ready read models over the books: the transactions window (full row universe, three-state status, keyset pagination), the per-row booking view, data coverage, and the connections catalog. - name: Accounting description: >- The accountant's read models: general ledger, journal entries, context cards, the filings strip with previews, and the SQL explorer. Every endpoint here requires LAC staff access or the company admin role; other bearers receive 403. paths: /invoices/{invoice_id}/send: post: tags: - Invoicing summary: Send an e-invoice description: >- Issues a `maventa_einvoice` draft and transmits it over the e-invoice network: allocates the invoice number, stores the invoice, books the sale when LAC keeps the ledger, and queues the Finvoice send. For a partner-profile draft, the tenant's Maventa connection is only the material-handler transport: the partner stays the Finvoice seller and payment beneficiary, receives a bookkeeping PDF copy, and the invoice has no tenant ledger effect. The e-invoice network is the only buyer-delivery channel LAC transmits on. A partner-profile send also emails its seller a bookkeeping copy. Drafts on any other channel are refused with 409; `pdf_download` drafts are issued through `POST /invoices/{invoice_id}/finalize` instead. Requires a write-scoped key. operationId: sendInvoice parameters: - $ref: '#/components/parameters/InvoiceIdPath' requestBody: required: false content: application/json: schema: $ref: '#/components/schemas/CustomerIdBody' responses: '200': description: Updated invoice. content: application/json: schema: $ref: '#/components/schemas/PortalInvoice' '401': $ref: '#/components/responses/Unauthorized' '403': $ref: '#/components/responses/Forbidden' '409': description: >- The draft is not on the e-invoice channel, its VAT treatment needs human review, or the company requires invoice approval and this draft has none that matches it as written. components: parameters: InvoiceIdPath: name: invoice_id in: path required: true schema: type: string schemas: CustomerIdBody: type: object description: Optional company selector for write requests. properties: customer_id: type: string description: Target company. Optional for API keys. PortalInvoice: type: object description: >- One sales invoice, sales draft, or purchase invoice. Amounts are integer cents; interior fields beyond the stable ones vary by status. properties: id: type: string status: type: string delivery_channel: type: string document_type: type: string enum: - invoice - credit_note original_invoice_id: type: string original_invoice_number: type: string original_invoice_date: type: string format: date correction_reason: type: string credited_cents: type: integer format: int64 paid_cents: type: integer format: int64 description: Live allocated payment amount in integer cents. open_cents: type: integer format: int64 description: Amount still outstanding in integer cents. can_cancel_before_sending: type: boolean description: >- True only when this issued Maventa invoice has one queued intent, no provider attempt or id, no payment or earlier correction, and an active original journal. The write route repeats these checks under the outbound and journal locks. seller_name: type: string description: Customer-facing seller name captured for this invoice. seller_legal_name: type: string description: Registered legal seller name captured for this invoice. seller_business_id: type: string description: Seller Business ID captured for this invoice. seller_iban: type: string description: Payment account captured for this invoice. seller_profile_id: type: string description: Partner seller profile id; empty for the tenant's own sale. posts_ledger: type: boolean description: >- False for a partner sale. Such an invoice is excluded from this company's journal, VAT facts, receivables, aging, and overdue controls. partner_copy_status: type: string enum: - not_required - no_contact_email - pending - sending - sent - failed - ambiguous description: Delivery state of the partner's bookkeeping PDF copy. partner_copy_error: type: string description: Latest partner-copy delivery error. pdf_available: type: boolean description: Whether the exact issued PDF is registered as retained evidence. pdf_document_id: type: string description: Canonical evidence-document id for the issued PDF. pdf_sha256: type: string pattern: ^[0-9a-f]{64}$ description: SHA-256 of the exact bytes returned by the PDF endpoint. pdf_size_bytes: type: integer format: int64 description: Size of the retained PDF in bytes. approval_status: type: string enum: - none - awaiting - approved - rejected description: >- Where this draft stands with its approver, for a company whose `invoice_approval_policy` is `required`. Meaningful only while the row is a draft; an issued invoice carries an empty value because approval no longer applies to it. Changing a draft resets this to `none`: the approval was for the invoice as written. approval_requested_by: type: string description: Who asked for approval. approval_request_id: type: string pattern: ^[0-9a-f]{32}$ description: Stable identity of the current approval request. approval_decided_by: type: string description: Which approver approved it or sent it back. approval_reason: type: string description: Why an approver did not approve it. approval_created_by: type: string description: Who created the draft; this person cannot decide it. approval_revision: type: string pattern: ^[0-9a-f]{64}$ description: Material sales invoice revision that approve or return must echo. approval_returned_revision: type: string pattern: ^[0-9a-f]{64}$ description: >- Material revision that was returned. A new request needs a different current revision. review_revision: type: string description: >- Current commercial/source review revision of a purchase invoice; accounting-only coding is excluded. review_next_action: type: string enum: - verify - approve - returned - approved - ready_for_payment - payment_in_progress - paid - source_unavailable - payment_details_missing review_can_decide: type: boolean description: Whether this person may perform the next purchase review action. review_history: type: array items: type: object additionalProperties: true review_evidence: type: array items: type: object required: - document_id - document_type - name properties: document_id: type: string document_type: type: string name: type: string content_type: type: string has_original: type: boolean description: >- Whether a retained supplier-invoice source document is available; explicit receipt/supporting attachments do not qualify. customer: $ref: '#/components/schemas/Party' lines: type: array items: $ref: '#/components/schemas/InvoiceLine' additionalProperties: true Party: type: object description: >- An invoicing counterparty (the customer you invoice), with e-invoice routing and per-party defaults. Rates in basis points (25.5% = 2550). required: - name properties: id: type: string description: Party id. Include on upsert to update an existing party. name: type: string business_id: type: string description: Finnish business ID (Y-tunnus), e.g. `1234567-8`. vat_number: type: string description: EU VAT number, e.g. `FI12345678`. address_line1: type: string postal_code: type: string city: type: string country_code: type: string description: ISO 3166-1 alpha-2, e.g. `FI`. email: type: string einvoice_address: type: string description: E-invoice (verkkolasku) address, e.g. an OVT identifier. einvoice_operator: type: string description: E-invoice operator/intermediator code. default_payment_terms_days: type: integer default_vat_code: type: string default_vat_rate_basis_points: type: integer description: Default VAT rate in basis points (25.5% = 2550). default_invoice_language: type: string InvoiceLine: type: object description: >- One invoice line. Money in integer cents; VAT rate in basis points; quantity is a decimal string. required: - description - quantity - unit_price_cents - net_cents - vat_cents - gross_cents properties: description: type: string quantity: type: string description: Decimal quantity as a string, e.g. `"2.5"`. unit_price_cents: type: integer description: Unit price in integer cents. vat_rate_basis_points: type: - integer - 'null' description: VAT rate in basis points (25.5% = 2550); null when not applicable. vat_code: type: string description: VAT treatment code. net_cents: type: integer description: Line net amount in integer cents. vat_cents: type: integer description: Line VAT amount in integer cents. gross_cents: type: integer description: Line gross amount in integer cents. Error: type: object description: Standard error envelope. properties: error: type: string description: Machine-readable error message. detail: type: string description: Human-readable detail. responses: Unauthorized: description: Missing or invalid bearer token. content: application/json: schema: $ref: '#/components/schemas/Error' Forbidden: description: >- Insufficient scope or role — e.g. a read-scoped key on a mutating method, or an API key on an interactive-session-only endpoint. content: application/json: schema: $ref: '#/components/schemas/Error' securitySchemes: apiKey: type: http scheme: bearer bearerFormat: lac_sk_... description: >- Portal API key minted in portal Settings → API access. Scope `read` or `write`; pinned to one company. Send as `Authorization: Bearer lac_sk_...`. ````