Outsourced Payroll Processing for CPA Firms

For a U.S. CPA firm, payroll support may involve checking client-approved inputs, preparing pay-run registers, maintaining payroll records and reconciling payroll liabilities to the accounting ledger. The provider prepares the agreed work; the firm or its authorized client contact retains pay-run approval, payment authority and any filing responsibility not expressly included in the engagement.

This guide explains which payroll preparation tasks can be delegated, how to work with the payroll and accounting systems already in use, what to confirm about U.S. payroll records and jurisdictional requirements, and how to define the review, filing and payment boundaries before the first run.

What CPA Firms Can Delegate

Depending on the engagement, preparation support may include:

• Checking approved hours, salary changes, commissions, deductions and other client-provided payroll inputs
• Preparing a draft payroll register and pre-run summary for the authorized approver
• Maintaining payroll records and organizing supporting reports from the existing payroll system
• Reconciling payroll-register totals, payroll-liability accounts and related accounting entries
• Preparing agreed payroll tax workpapers or returns when expressly included in scope
• Documenting missing inputs, late changes, unusual amounts and unresolved differences for review

The provider does not decide employee-versus-contractor status, compensation policy, benefit eligibility or employment actions. The CPA firm and its client retain those decisions. Pay-run approval, payment initiation and filing authority are identified separately rather than assumed to transfer with preparation work.

How It Works in Common Payroll Software

QuickBooks Online Payroll

Where QuickBooks Online Payroll is linked to the client's accounting company, the actual posting and reporting workflow depends on its configuration and selected settings. Preparation support may include:

• Checking approved payroll inputs against the draft register
• Preparing a pre-run summary and listing missing or unusual items for the approver
• Reviewing payroll reports and the resulting accounting entries after the authorized run
• Reconciling payroll expense and liability balances to the payroll register and payment records

The authorized client contact or payroll approver reviews and submits the run. Preparation access does not require bank credentials, direct-deposit authorization or payment execution rights.

Xero and Connected Payroll Applications

Where a client uses Xero as its accounting ledger and a separate payroll application for pay runs, the preparation workflow should identify which system holds employee records, calculates pay, produces payslips and handles tax submissions. Support may include reconciling the approved payroll register and liability reports to the Xero ledger, using the client's existing integration and access settings.

Gusto

For clients using Gusto, the agreed workflow may include checking approved payroll inputs, preparing the pay run for review, reconciling payroll reports to the accounting ledger and tracking filing confirmations or notices. Filing availability and responsibility depend on the client's subscription, jurisdiction, account setup and agreed scope; do not assume every return is included or completed automatically without checking the account's records.

ADP

ADP access and available reports vary by product, service package and user role. A CPA-firm support workflow may use authorized payroll registers, tax-liability reports and accounting outputs to reconcile payroll totals, accruals and liabilities to the general ledger. The scope should specify the reports available and keep pay-run approval and payment controls with the authorized client contact.

U.S. Payroll Requirements to Confirm With the Responsible Professional

Payroll requirements depend on the employer, employee work locations, pay arrangements and applicable federal, state and local rules. The CPA firm or responsible payroll tax professional should confirm which registrations, withholding rules, deposits, returns and year-end forms apply to each client before processing begins.

• Employee and employer records: Confirm the approved employee data, Forms W-4 and relevant state withholding information supplied for the engagement.
• Federal and state obligations: Identify the payroll tax deposits, returns and year-end reporting that apply to the employer. Do not assume the same filing calendar or requirements for every client.
• Work locations: Employees working in more than one state or remotely from a different state may create registration or withholding questions. The responsible tax professional determines the obligations; preparation support follows the documented instructions.
• Filing responsibility: Specify whether the payroll platform, CPA firm, client or another authorized provider prepares and submits each return, and who reviews and confirms completion.

Payroll pricing depends on the defined processing scope, but cost comparison is a separate buyer question from the CPA firm's recurring workflow. For cost drivers, quote components and bank-access controls, see our payroll cost and red-flags article.

The Questions That Actually Come Up Before Outsourcing Payroll

These are practical questions a CPA firm should settle with the client and payroll provider before the first pay cycle:

“What happens if payroll runs late?”

Set a data cutoff relative to each pay date and identify who supplies, checks and approves late changes. The payroll calendar should allow time for input validation, exception resolution, reviewer approval and payment processing. If records arrive after cutoff, log the affected employee and period, obtain an authorized decision and follow the agreed current-run or next-run procedure.

“Do they have access to our bank account?”

The provider prepares the pay-run information and returns it for review. An authorized client or payroll approver confirms the register and initiates or approves payment through the client's established process. Preparation access does not include bank credentials, direct-deposit authorization or payment execution rights.

“Can they handle equity compensation / RSUs / stock options?”

Equity compensation can require fact-specific tax and payroll treatment. The responsible tax professional determines the applicable treatment and withholding instructions; the preparation provider can process the approved payroll inputs and reconcile the resulting register and liabilities. Do not infer treatment from an equity-platform event alone.

“What if we have employees in multiple states?” (US)

Multi-state processing depends on the employer's registrations, employee work locations and the withholding instructions confirmed by the responsible tax professional. The provider follows the approved state-by-state setup and flags missing or inconsistent information; it does not independently determine registration or tax obligations.

“What about contractor payments?”

Contractor payments follow a separate process from employee payroll. The client or qualified adviser determines worker classification and the applicable reporting treatment. Preparation support follows that determination and organizes the approved payment and reporting records; it does not classify workers.

“What’s the most common mistake in the handoff?”

Three recurring control gaps are unclear input cutoffs, missing approval of pay or employee changes, and failure to reconcile payroll-register totals and liabilities to the accounting ledger. A checklist should name the person responsible for each input, the reviewer, the approval point and the process for resolving differences.

What CPA Firms Should Confirm Before the First Run

• Which payroll software is the team working inside — yours, or theirs?
• Who has bank account access and payment authorization? (should be you)
• What is the timesheet/data submission cutoff?
• What is the review step before submission?
• Who handles payroll tax filings — the payroll team, your accountant, or the software automatically?
• How are payroll GL entries reconciled, and how frequently?
• What is the process for new hires, terminations, and changes mid-period?