API · Manage · Filings
Create a filing.
Canonical — and only — filing submission endpoint. type discriminates the payload shape; see /concepts/filings for per-type payloads. Covers every state filing, BOI, IRS forms (966, 1120, 1120-W), and SEC filings (Form D, blue-sky notices). Entity lifecycle verbs (/dissolve, /qualify, /convert, /registered_agent) emit their own filings as side effects — do not double-submit via this endpoint.
Returns 202 Accepted. On completion, emits one of: filing.submitted, filing.accepted, filing.rejected. Subscribe via `POST /v1/webhook_endpoints` to consume.
Sub-agent rail. This endpoint dispatches a browser-automation sub-agent to the relevant government website when type is annual_report, franchise_tax, or boi_report (DE SOS for the first two; FinCEN BOI E-Filing System for the third). The 202 carries the Filing id; subscribe to sub_agent_session.completed for sub-agent visibility, or just wait for filing.accepted for the customer-facing terminal. Other filing types remain on the direct API rail.
Pre-conditions: entity must be in a state that accepts the filing's type. See lifecycle › What you can call in each state for the full matrix. Returns 422 invalid_filing_type_for_state otherwise.
Last updated
Query Parameters
dry_runbooleanOptionalIf true, simulate the mutation and return the would-be resource, any cascaded
resources, and a fee estimate — without side effects. Available on every mutation.
Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
typestringRequiredDiscriminator for payload shape. Does not include action-driven filings
(certificate_of_incorporation, certificate_of_dissolution, ein_application,
foreign_qualification, registered_agent_change, conversion,
certificate_of_merger) — those are emitted as side effects of their
corresponding entity verbs and cannot be created directly through this endpoint.
"certificate_of_amendment""annual_report""franchise_tax""final_franchise_tax""boi_report""boi_update""form_966""form_1120""form_1120w""form_d""blue_sky_notice""stock_split""custom"payloadobjectRequiredResponse Body
application/json
application/problem+json
application/problem+json
application/problem+json
application/problem+json
application/problem+json
Request
curl -X POST "https://api.mattermode.com/v1/entities/{id}/filings" \ -H "Content-Type: application/json" \ -d '{ "type": "certificate_of_amendment", "payload": {} }'const body = JSON.stringify({ "type": "certificate_of_amendment", "payload": {}})fetch("https://api.mattermode.com/v1/entities/{id}/filings", { method: "POST", headers: { "Content-Type": "application/json" }, body})package mainimport ( "fmt" "net/http" "io/ioutil" "strings")func main() { url := "https://api.mattermode.com/v1/entities/{id}/filings" body := strings.NewReader(`{ "type": "certificate_of_amendment", "payload": {} }`) req, _ := http.NewRequest("POST", url, body) req.Header.Add("Content-Type", "application/json") res, _ := http.DefaultClient.Do(req) defer res.Body.Close() body, _ := ioutil.ReadAll(res.Body) fmt.Println(res) fmt.Println(string(body))}import requestsheaders = { "Authorization": "Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc", "Matter-Version": "2026-06-10", "Idempotency-Key": "ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b",}payload = { "type": "certificate_of_amendment", "payload": {}}resp = requests.post( "https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/filings", headers=headers, json=payload,)resp.raise_for_status()print(resp.json())import java.net.URI;import java.net.http.HttpClient;import java.net.http.HttpRequest;import java.net.http.HttpResponse;import java.net.http.HttpResponse.BodyHandlers;import java.time.Duration;import java.net.http.HttpRequest.BodyPublishers;var body = BodyPublishers.ofString("""{ "type": "certificate_of_amendment", "payload": {}}""");HttpClient client = HttpClient.newBuilder() .connectTimeout(Duration.ofSeconds(10)) .build();HttpRequest.Builder requestBuilder = HttpRequest.newBuilder() .uri(URI.create("https://api.mattermode.com/v1/entities/{id}/filings")) .header("Content-Type", "application/json") .POST(body) .build();try { HttpResponse<String> response = client.send(requestBuilder.build(), BodyHandlers.ofString()); System.out.println("Status code: " + response.statusCode()); System.out.println("Response body: " + response.body());} catch (Exception e) { e.printStackTrace();}using System;using System.Net.Http;using System.Text;var body = new StringContent("""{ "type": "certificate_of_amendment", "payload": {}}""", Encoding.UTF8, "application/json");var client = new HttpClient();var response = await client.PostAsync("https://api.mattermode.com/v1/entities/{id}/filings", body);var responseBody = await response.Content.ReadAsStringAsync();curl --request POST 'https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/filings' \ --header 'Authorization: Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc' \ --header 'Matter-Version: 2026-06-10' \ --header 'Idempotency-Key: ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b' \ --header 'Content-Type: application/json' \ --data '{ "type": "certificate_of_amendment", "payload": {}}'const response = await fetch("https://api.mattermode.com/v1/entities/ent_Nq3KcAbc/filings", { method: "POST", headers: { "Authorization": "Bearer sk_test_4eC39HqLyjWDarjtT1zdp7dc", "Matter-Version": "2026-06-10", "Idempotency-Key": "ee7c3a9b-3f1a-4d8e-9b2a-7c5e1f0a2d4b", "Content-Type": "application/json", }, body: JSON.stringify({ "type": "certificate_of_amendment", "payload": {} }),});if (!response.ok) { throw new Error(`Matter API ${response.status}: ${await response.text()}`);}const data = await response.json();console.log(data);Response
application/json{
"id": "string",
"object": "filing",
"entity_id": "ent_Nq3KcAbc",
"type": "certificate_of_amendment",
"jurisdiction": "US-DE",
"status": "preparing",
"payload": {},
"submitted_at": 1745539200,
"accepted_at": 1745539200,
"rejected_reason": "string",
"state_confirmation_number": "string",
"document_ids": [
"string"
],
"fees": {},
"cancellation_window_ends_at": 0,
"metadata": {},
"created": 1745539200,
"updated": 1745539200,
"livemode": false
}{
"type": "https://mattermode.com/docs/errors/invalid_request",
"title": "Invalid request",
"status": 400,
"code": "invalid_request",
"detail": "Request body could not be parsed as JSON.",
"doc_url": "https://mattermode.com/docs/guides/errors#invalid_request",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/authentication_required",
"title": "Authentication required",
"status": 401,
"code": "authentication_required",
"detail": "No bearer token was supplied. Pass `Authorization: Bearer sk_live_...` on every request.",
"doc_url": "https://mattermode.com/docs/guides/errors#authentication_required",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/invalid_state_transition",
"title": "Invalid state transition",
"status": 409,
"code": "invalid_state_transition",
"detail": "Entity ent_Nq3KcAbc is in state `dissolved`; `dissolve` is not a valid transition.",
"doc_url": "https://mattermode.com/docs/guides/errors#invalid_state_transition",
"request_id": "req_Qw9xYz8A",
"current_state": "dissolved",
"attempted_transition": "dissolve",
"allowed_transitions": []
}{
"type": "https://mattermode.com/docs/errors/dissolution_prerequisites_missing",
"title": "Dissolution prerequisites missing",
"status": 409,
"code": "dissolution_prerequisites_missing",
"detail": "Voluntary dissolution requires `board_resolution_id` and `stockholder_consent_id`, or `auto_generate_resolutions: true`.",
"doc_url": "https://mattermode.com/docs/guides/errors#dissolution_prerequisites_missing",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/valuation_stale",
"title": "409A valuation stale",
"status": 409,
"code": "valuation_stale",
"detail": "Active 409A val_AbCd1234 is older than 12 months or superseded by a material event. Issuing ISOs at the prior strike risks IRC §409A violation. Refresh via POST /entities/{id}/valuations/{id}/refresh_request.",
"doc_url": "https://mattermode.com/docs/guides/errors#valuation_stale",
"request_id": "req_Qw9xYz8A"
}{
"type": "https://mattermode.com/docs/errors/validation_failed",
"title": "Validation failed",
"status": 422,
"code": "validation_failed",
"detail": "One or more fields failed validation. See `errors[]`.",
"doc_url": "https://mattermode.com/docs/guides/errors#validation_failed",
"request_id": "req_Qw9xYz8A",
"errors": [
{
"field": "founders[0].equity",
"code": "out_of_range",
"message": "Equity must sum to 100% across all founders."
}
]
}{
"type": "https://mattermode.com/docs/errors/rate_limit_exceeded",
"title": "Rate limit exceeded",
"status": 429,
"code": "rate_limit_exceeded",
"detail": "Request rate exceeded for this key. Retry after `retry_after` seconds or honor the `Retry-After` header.",
"doc_url": "https://mattermode.com/docs/guides/errors#rate_limit_exceeded",
"request_id": "req_Qw9xYz8A",
"retry_after": 30
}