Embedded payroll is payroll processing that a vertical SaaS or financial platform offers inside its own app, built on a payroll provider’s API. The provider calculates pay, files and pays taxes and moves the money. The platform owns the customer experience and, depending on the setup, part of the funding risk. Payment speed decides how much: faster payroll means money leaves before the employer’s debit has cleared.
What the provider runs and what the platform runs
Gusto Embedded is a useful worked example because its documentation spells out the split. It covers regular and off-cycle payroll, contractor payments and the federal, state and local filings and payments that go with them.
| Layer | Provider (Gusto Embedded) | Platform |
|---|---|---|
| Payroll math and tax filing | Calculates payroll, files and pays taxes | Collects accurate company and employee data |
| User interface | Optional pre-built Flows or React SDK | Builds its own screens if it uses the API directly |
| Money movement | Debits the employer and pays employees by ACH | Sets payment speed and fast-payment limits |
| Funding risk | Collects failed debits first | Can inherit unpaid debts after 90 days on faster speeds |
| Approval | Commercial, security and implementation reviews before production | Applies and passes those reviews |
Gusto also lists product partnerships a platform can add, including health insurance through SimplyInsured, on-demand pay through Clair, workers’ compensation through NEXT Insurance, 401(k) plans through Guideline and accounting sync with Xero and QuickBooks Online.
Ways to build
Gusto offers four approaches: the API, a React SDK, pre-built Flows, or a mix of them.
- API: the most control and the most work. The platform must surface the validations and error handling the API returns.
- React SDK: components with built-in business logic, limited to supported props and styling.
- Flows: hosted screens opened in a new tab or an iframe. A flow link expires after 1 hour of inactivity and 24 hours after creation, and can be regenerated with saved data intact.
Gusto recommends Flows for complex steps such as state tax setup and importing external payrolls, and says a few functions are only available through Flows. Most platforms therefore end up with a hybrid build.
Payment speed is a credit decision
Gusto Embedded supports next-day, 2-day and standard 4-day payroll. In each case the employer runs payroll by 4 p.m. PT.
| Speed | Run payroll | Employees paid by direct deposit |
|---|---|---|
| Next-day (opt-in partners only) | Thursday | Friday |
| 2-day | Wednesday | Friday |
| 4-day | Monday | Friday, if the employer debit succeeded |
On 4-day payroll, Gusto knows whether the employer’s debit succeeded before employees are paid. On faster speeds it is not. Gusto’s documentation states that it starts paying employees before it has confirmed a cleared debit from the company’s bank account.
If that debit fails, the company goes into collections. Gusto says that if the company does not pay, the liability transfers to the platform after 90 days. In effect, a platform that switches on fast payroll is extending short-term credit to its customers.
The controls that limit exposure
The main control is fast_payment_limit. It caps the total of all payrolls a company can run on next-day or 2-day speed in a 24-hour window. Anything above the limit drops to 4-day processing. If a payroll is moved for that reason, the user must cancel it and the platform must raise the limit before it is run again.
Gusto suggests several practices around that limit:
- explain payment speed and its tradeoffs to employers inside the product;
- connect the employer’s bank account through Plaid, which also shows a last cached balance that can inform limits;
- let customers ask support for temporary or permanent limit increases;
- consider pay frequency, since more frequent pay runs mean smaller payrolls.
Next-day speed is only available to partners that opt in, and Gusto does not allow it when AutoPilot is enabled. A company’s default speed comes from the configuration agreed with Gusto’s implementation team.
Reverse wires and partner-funded payroll
Not every payroll is funded by an ACH debit of the employer. Gusto’s API exposes reverse wire transactions: debits Gusto initiates to pull funds from a partner’s bank account to cover payroll or contractor payment obligations. A company can also be configured for a partner-owned disbursement rail.
Both settings change who funds payroll on the day. A platform that uses them needs the same controls a lender would apply: limits per customer, monitoring of failed collections and a reserve for losses. Onboarding those business customers is covered in connected account onboarding, and the wider platform model in embedded finance for vertical SaaS.
