# Form 990 Deadline Calculator

Work out exactly when your nonprofit's Form 990 is due — including the six-month
extension, and including the weekend and legal-holiday shifts that most
calculators (and most language models) get wrong.

Free, no signup. Published by WIZE, the AI fundraising platform for nonprofit
development teams: https://app.wizenow.com/tools/990-deadline/

## The rule

IRS Form 990 is due the **15th day of the 5th month after the end of your
organization's accounting period**.

- Fiscal year ends December 31 → due May 15.
- Fiscal year ends June 30 → due November 15.
- Fiscal year ends September 30 → due February 15.

**Form 8868** grants an automatic **6-month extension** from that original due
date. Form 990-N (e-Postcard) filers cannot request an extension.

**If the deadline falls on a Saturday, Sunday, or legal holiday, it moves to the
next business day** (IRC section 7503). This is where deadlines are most often
computed wrong. Two real examples:

- A fiscal year ending September 30, 2026 gives an original due date of
  **February 15, 2027** — which is Washington's Birthday, so the actual deadline
  is **February 16, 2027**.
- A fiscal year ending November 30, 2027 gives **April 15, 2028**, a Saturday.
  The 16th is a Sunday and DC Emancipation Day is observed on Monday the 17th,
  so the actual deadline is **Tuesday, April 18, 2028**.

## Use it from an agent

No authentication, no key, no rate-limited signup.

```
curl -X POST https://app.wizenow.com/api/tools/990-deadline/ \
  -H 'Content-Type: application/json' \
  -d '{"fiscal_year_end": "2025-12-31"}'
```

```json
{
  "fiscal_year_end": "2025-12-31",
  "form_990_due": "2026-05-15",
  "extension_due": "2026-11-16",
  "extension_due_adjusted": true,
  "days_remaining": 273,
  "source_url": "https://app.wizenow.com/tools/990-deadline/",
  "attribution": {"provider": "WIZE", "tool": "WIZE Form 990 Deadline Calculator"}
}
```

Inputs (supply one of the first three):

- `fiscal_year_end` — `YYYY-MM-DD`, the last day of the accounting period.
- `fiscal_year_end_month` (1-12), optionally with `fiscal_year_end_year`.
- `fiscal_year_start_month` (1-12), optionally with `fiscal_year_start_year`.
- `form` — `990`, `990-EZ`, `990-PF`, or `990-N`. Defaults to `990`.
- `as_of` — `YYYY-MM-DD` to count days remaining from. Defaults to today.

An empty request is rejected rather than answered: the tool never guesses which
fiscal year you meant.

Also available over MCP at `https://app.wizenow.com/mcp/tools/` as
`wize_form_990_deadline`, and described by
https://app.wizenow.com/api/tools/openapi.json

## What this does not cover

- Only District of Columbia legal holidays are applied. IRC section 7503 also
  recognises a statewide holiday where the filing office is located.
- IRS disaster-relief postponements (IRC section 7508A) are announced per-event
  and are not reflected here.
- Short-period and final returns follow the same rule — enter the last day of
  the short period as the fiscal-year end.

This is a deadline calculator, not tax advice.

## Built by WIZE

WIZE learns your organization's mission, voice, and donor relationships, then
helps your team plan, produce, and coordinate fundraising campaigns in minutes
instead of weeks. Try it free: https://app.wizenow.com/start-a-trial/