Taxes, Agencies, and Jurisdictions

Payroll taxes involve three related concepts. Before working with Check's APIs, it helps to understand what each one is in the real world and how they connect.

• Jurisdiction — a geographic region — federal, a state, or a locality within a state — whose government imposes payroll taxes on employers operating there. It's the where of a tax, as opposed to the agency, which is the who you register, pay, and file with.
• Agency — the government body, or an administrator it appoints, that employers actually interact with: who you register with, remit payments to, and file returns with. Examples include the IRS, a state department of revenue, or a local collector such as Berkheimer in Pennsylvania.
• Tax — a specific levy owed within a jurisdiction, such as Federal Income Tax, a state's unemployment insurance tax (SUI), or a locality's Local Services Tax.

These connect in a natural hierarchy: within a jurisdiction, a government levies one or more taxes, and each tax is administered by an agency. A single agency often administers many taxes, and a jurisdiction can have several agencies — for example, a state revenue department for income tax withholding and a separate department for unemployment insurance. Employers never transact with a jurisdiction directly; they register, pay, and file with an agency.

Check exposes Tax and Agency as read-only reference resources, and uses jurisdiction as a consistent code for grouping and filtering them. Both resources are identical across companies and stable across environments.

Jurisdictions

A jurisdiction is represented as a lowercase code:

• fed for the federal government.
• A lowercased ISO 3166-2:US region code for a state or the District of Columbia — essentially the two-letter postal code in lowercase (ny, pa, ca, dc).

A few behaviors are worth calling out:

• Localities roll up to their state. A local tax or agency carries the code of the state it sits in, so pa covers Pennsylvania's state-level and local entries.
• The code is the same everywhere. Every Check resource that needs a jurisdiction uses this same code, so you can group and filter consistently across resources.
• The format extends internationally. Non-US jurisdictions prefix the country (for example, ca_qb for Québec). Today the catalog is US-only.

See Jurisdictions for the complete list of codes. Check is consolidating every resource onto this single canonical code; if you currently rely on older jurisdiction representations such as jur_ IDs, see Jurisdiction Canonicalization.

Taxes

A Tax is a specific levy that can arise when running payroll. Each tax carries the jurisdiction it belongs to, who pays it, whether Check supports it, and dating for the obligation itself.

{
  "id": "tax_8L3JLfsH4X6dp0maBWfW",
  "label": "Federal Income Tax",
  "jurisdiction": "fed",
  "payer": "employee",
  "supported": true,
  "effective_from": "1900-01-01",
  "effective_to": null
}

See the Tax object for the full field reference.

How taxes relate to agencies

In the real world, every tax is administered by an agency. That relationship is not fixed, though: the administering agency for a tax can change over time as governments reappoint collectors, and penalties and interest on a tax can be owed to a different agency than the tax itself. For this reason, Check does not attach an agency directly to a tax. Instead, the relevant agency appears on the resources where an employer actually transacts — today on filings, and on remittances and notices in the future.

Listing taxes

List taxes (GET /taxes) returns the catalog, ordered with federal taxes first, then by jurisdiction, then by label. It supports these filters:

List every tax in Pennsylvania — state and local:

curl -X GET \
  'https://sandbox.checkhq.com/taxes?jurisdiction=pa' \
  -H 'Authorization: Bearer YOUR_API_KEY'

Agencies

An Agency is the operational counterparty Check transacts with on filings and remittances. It is intentionally minimal.

{
  "id": "agc_ukjABgbD0hQ3dfBRyMPD",
  "label": "Internal Revenue Service",
  "jurisdiction": "fed"
}

See the Agency object for the full field reference. As described above, agencies are referenced from the resources where employers transact with them — filings today, remittances and notices in the future.

Listing agencies

List agencies (GET /agencies) supports id, jurisdiction, label_contains, and limit, with the same repeatable, ordering, and pagination behavior as taxes.

Look up an agency by name:

curl -X GET \
  'https://sandbox.checkhq.com/agencies?label_contains=berkheimer' \
  -H 'Authorization: Bearer YOUR_API_KEY'

Both resources are read-only reference data: there are no webhooks, and a single-resource lookup returns a standard 404 on an unknown ID.