# GST/HST Filing Period

> Solarium docs, Reports. All requests are `POST https://api.trysolarium.com/graphql/` with `Authorization: Bearer <api key>` and a JSON body `{"query": ..., "variables": ...}`. Every query and mutation takes an `organizationId` (find it with `myOrganizations`). Index of all pages: https://trysolarium.com/llms.txt

Canadian organizations. The organization's GST/HST filing period by its filing frequency (monthly, quarterly or annual — calendar months/quarters/years). offset 0 is the latest period that has already ended (the return you'd file now); -1 is the one before it, 1 is the period in progress. Returns the dates to pass to gstHstReturn plus the due date (null for annual filers, whose deadline depends on the filer).

### Arguments

| Name | Type | Required | Description |
| --- | --- | --- | --- |
| `organizationId` | `UUID!` | Yes | Organization ID |
| `offset` | `Int` | No | Periods from the latest ended one (default 0) |

### Request

```graphql
query {
  filingPeriod(organizationId: "a1b2c3d4-...", offset: 0) {
    frequency
    label
    startDate
    endDate
    dueDate
    offset
  }
}
```

### Response

```json
{
  "data": {
    "filingPeriod": {
      "frequency": "quarterly",
      "label": "Q3 2026",
      "startDate": "2026-07-01",
      "endDate": "2026-09-30",
      "dueDate": "2026-10-31",
      "offset": 0
    }
  }
}
```