Tax API
10 endpoints in this group.
GET /api/tax/due-dates
Get Due Dates
Parameters
| Name | In | Type | Required | Description |
|---|---|---|---|---|
tax_year | query | — | optional |
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
POST /api/tax/federal
Calculate Federal
Calculate federal income tax liability.
Request body: application/json
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
POST /api/tax/net-income
Calc Net Income
Calculate net LLC income for the tax year (Section 475(f) ordinary income). Includes car deduction (prorated), all LLC deductions, and NOL (80% cap).
Request body: application/json
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
GET /api/tax/payments
List Payments
List estimated tax payments. P0-8: limit capped at 100.
Parameters
| Name | In | Type | Required | Description |
|---|---|---|---|---|
tenant_id | query | — | optional | |
tax_year | query | — | optional | |
limit | query | integer | optional | Page size (max 100). Legacy — prefer ?page_size=. |
page_size | query | — | optional | Canonical page size. Must be one of 25, 50, 100. When supplied, overrides ?limit=. |
cursor | query | — | optional | Opaque pagination cursor from a previous page's next_cursor. |
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
POST /api/tax/payments
Log Payment
Request body: application/json
Responses
| Code | Description |
|---|---|
201 | Successful Response |
422 | Validation Error |
POST /api/tax/quarterly-estimate
Quarterly Estimate
Compute estimated quarterly tax payment.
Implements:
- YTD P&L annualization based on days_elapsed
- Full SE tax (Schedule SE) — no longer stubbed to 0
- NOL carryforward with 80% TCJA cap
- Child tax credit with phase-out
- Safe-harbor comparison (Method 1 vs Method 2) — picks lower
- Penalty risk traffic light (green / amber / red)
- State tax estimate
Request body: application/json
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
POST /api/tax/safe-harbor
Safe Harbor
Calculate IRS safe-harbor payment.
Method 1: 100% of prior-year tax (110% if prior AGI > $150,000). Method 2: 90% of current-year projected tax. Recommended: whichever is LOWER (IRS allows either).
Request body: application/json
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
POST /api/tax/se-tax
Calc Se Tax Endpoint
Calculate Schedule SE self-employment tax. Returns se_tax, deductible_half, and se_income_subject.
Request body: application/json
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
POST /api/tax/send-reminder
Send Reminder
Send quarterly tax payment reminder email.
Parameters
| Name | In | Type | Required | Description |
|---|---|---|---|---|
tenant_id | query | — | optional | |
quarter | query | integer | required |
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |
GET /api/tax/wash-sales
List Wash Sales
Parameters
| Name | In | Type | Required | Description |
|---|---|---|---|---|
tenant_id | query | — | optional | |
tax_year | query | — | optional | |
symbol | query | — | optional | |
account_ids | query | — | optional | |
window_days | query | integer | optional | |
include_substitutes | query | boolean | optional |
Responses
| Code | Description |
|---|---|
200 | Successful Response |
422 | Validation Error |