Verify Canadian Social Insurance Number (SIN) structure
Verify Canadian Social Insurance Number (SIN) structure, Modulo 10 Luhn checksum, regional ESDC office allocation, temporary resident status (starts with 9), and known test numbers
Request
- x-api-key: <your-api-key>
- Content-Type: application/json
Response
{
"isValid": true,
"sinDetails": {
"firstDigit": "<first digit>",
"formattedPrint": "PL61 1090 1014 0000 0712 1981 2874",
"masked": "<masked>",
"normalized": "PL61109010140000071219812874",
"provinces": [
"<province>"
],
"rawInput": "PL61109010140000071219812874",
"regionName": "Ada Lovelace"
},
"status": "success",
"tokensDeducted": 1,
"validationResult": {
"isFirstDigitValid": true,
"isFormatValid": true,
"isKnownTestNumber": true,
"isLuhnValid": true,
"isTemporaryResident": true,
"reason": "checksum ok"
}
}What it does
Verify Canadian Social Insurance Number (SIN) structure, Modulo 10 Luhn checksum, regional ESDC office allocation, temporary resident status (starts with 9), and known test numbers
Request
Body
| Field | Type | Required | Description |
|---|---|---|---|
sin | string | yes | Canadian Social Insurance Number string (e.g. "000 000 000", "000-000-000", or "000000000") |
Example request
{
"sin": "046 454 286"
}Response
| Field | Type | Description |
|---|---|---|
isValid | boolean | |
sinDetails | object | |
↳ firstDigit | string | |
↳ formattedPrint | string | |
↳ masked | string | |
↳ normalized | string | |
↳ provinces | array<string> | |
↳ rawInput | string | |
↳ regionName | string | |
status | string | |
tokensDeducted | integer | |
validationResult | object | |
↳ isFirstDigitValid | boolean | |
↳ isFormatValid | boolean | |
↳ isKnownTestNumber | boolean | |
↳ isLuhnValid | boolean | |
↳ isTemporaryResident | boolean | |
↳ reason | string |
Example response
{
"isValid": true,
"sinDetails": {
"firstDigit": "<first digit>",
"formattedPrint": "PL61 1090 1014 0000 0712 1981 2874",
"masked": "<masked>",
"normalized": "PL61109010140000071219812874",
"provinces": [
"<province>"
],
"rawInput": "PL61109010140000071219812874",
"regionName": "Ada Lovelace"
},
"status": "success",
"tokensDeducted": 1,
"validationResult": {
"isFirstDigitValid": true,
"isFormatValid": true,
"isKnownTestNumber": true,
"isLuhnValid": true,
"isTemporaryResident": true,
"reason": "checksum ok"
}
}Errors
Every error answers with the same envelope: an HTTP status, a machine code and a sentence.
400 | The body or a parameter failed validation. The details array names the field. |
401 | No key, a revoked key or a wrong header. Send x-api-key. |
402 | The wallet cannot cover this call. Top up or wait for the monthly grant. |
404 | The resource does not exist, or it is not yours. Both answer identically and cost nothing. |
429 | Over the per-minute quota of your tier. Back off and retry. |
5xx | Upstream refused or timed out. The call is not billed. |
Code
curl -X POST 'https://app.castomapi.com/v1/verify/sin' \
-H 'x-api-key: <your-api-key>' \
-H 'Content-Type: application/json' \
-d '{"sin": "046 454 286"}'const res = await fetch('https://app.castomapi.com/v1/verify/sin', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"sin": "046 454 286"})
});
const data = await res.json();
console.log(data);import { request } from 'node:https';
// Node 18+ has fetch built in
const res = await fetch('https://app.castomapi.com/v1/verify/sin', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"sin": "046 454 286"})
});
const data = await res.json();
console.log(data);import requests
res = requests.post(
'https://app.castomapi.com/v1/verify/sin',
headers={'x-api-key': '<your-api-key>'},
json={"sin": "046 454 286"},
timeout=30,
)
print(res.json())<?php
$ch = curl_init('https://app.castomapi.com/v1/verify/sin');
curl_setopt_array($ch, [
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => ['x-api-key: <your-api-key>', 'Content-Type: application/json'],
CURLOPT_POSTFIELDS => json_encode(['sin' => '046 454 286']),
]);
$data = json_decode(curl_exec($ch), true);
print_r($data);Cost and limits
This operation needs no API key and costs nothing: called without a key it answers 200 and deducts zero tokens, up to 10 requests a minute per IP address.
Rate limits per minute
| No key | 10 |
| Free | 60 |
| Pro | 300 |
| Enterprise | 1200 |
Questions
What does Verify Canadian Social Insurance Number (SIN) structure cost?
This operation needs no API key and costs nothing: called without a key it answers 200 and deducts zero tokens, up to 10 requests a minute per IP address.
How do I authenticate?
Send your key in the x-api-key header. One key covers every metered endpoint; there is nothing to enable per endpoint.
Can I send an Authorization: Bearer token instead?
Not for a metered endpoint — those take the x-api-key header and nothing else. Bearer tokens belong to the account side: the dashboard and account APIs accept a JWT session, and castomapi-auth issues those through a standard OAuth2 handshake, with authorization code, client credentials and refresh grants. The auth service page covers it.
What are the limits?
10 requests a minute per IP with no key at all, 60 a minute on the free tier, 300 on Pro, 1200 on Enterprise. Above the no-key tier the quota is per account, across every endpoint.
OpenAPI: https://app.castomapi.com/docs/json