ADP TotalSource: registry status and platform lock-in

This offer differs from its peers in one structural way that shapes every other answer: the co-employment service runs on the parent company's payroll platform rather than on a system built only for co-employed clients. That has an obvious upside. Payroll engineering, tax filing infrastructure and reporting are mature, tested at very large scale, and unlikely to break during a growth year. It also has an unglamorous downside that buyers underweight at signature — your payroll data, integrations and reporting all sit inside one vendor's ecosystem, so an exit is a platform migration, not merely the end of a service agreement.

Both public registries carry this provider. Federal certification governs how the employment tax wage base is treated when a client transfers in or out part-way through a year, and independent accreditation covers the remittance and solvency review. With those settled, the commercial question is the fee shape. Public disclosure describes a per-head monthly charge, which behaves very differently from a payroll-percentage fee: it is predictable, it does not inflate when you give raises, and it becomes relatively expensive on a low-wage, high-headcount payroll where many small salaries each attract the same fixed charge. Seasonal and high-churn employers should ask specifically whether a mid-month joiner or leaver is billed as a full month, because that single answer moves the annual total more than the headline rate.

Ask the exit questions while the provider still wants your signature. Which data exports are contractual rather than discretionary, in what format, and how quickly. Whether the general ledger mapping and historical pay records travel with you. How the unemployment insurance account transfers in each state where you employ people, and who files the final returns. Whether the benefit plan year can be broken mid-term or whether you must wait for renewal. Those terms decide whether leaving costs a month of admin or most of a year, and they are negotiable exactly once.

Scale cuts both ways on service. A very large operator brings filing infrastructure that rarely fails and a compliance function that tracks statutory change across every state without being asked, which is worth real money to an employer hiring in unfamiliar jurisdictions. It also brings pooled support rather than a named team for smaller clients, so the answer to an unusual question can take longer to reach someone qualified to give it. Before signing, ask what the escalation path looks like for a payroll error discovered on a pay date, what the contracted response window is, and whether your account tier changes if headcount falls below a threshold during a slow year.

How to check this yourself

Test any quote against the employer cost model, compare registry entries with the Insperity page and the TriNet page, and browse the provider register for the full set. The duty split is explained under how co-employment allocates employer duties, high-churn payrolls should read the food service vertical, the platform-versus-co-employer distinction is covered in the Gusto classification answer, and the category starts at the PEO hub.

What this doesn't cover

What is published and checkable, nothing further. No rate, no ranking, no paid placement, and no view on service quality, which varies by client and cannot be read from a register. Benefit premiums and workers' compensation pricing are underwritten on your own census and are not published anywhere in advance. Contract terms described here are the ones to ask about, not terms we have seen in your agreement.