Payroll setup document checklist: what to collect from a new payroll client
Setting up payroll for a new client, or taking it over from another provider, comes down to having the right numbers before the first pay date. Missing a state account number or an employee's withholding form means guessing, and guesses in payroll turn into amended filings later. This guide lists what to collect from the business and its employees, and a way to gather it without a chain of emails.
A note on scope: this is a general starting list, not tax or legal advice. Requirements vary by state and by payroll system. FilesDue collects the documents; it does not run payroll.
Documents from the business
Tax accounts
- EIN confirmation letter from the IRS.
- State withholding account number and any notices showing it, for each state where employees work.
- State unemployment account number and current rate notice.
- Local tax account details, if the business is in a city or county with payroll taxes.
Pay setup
- Pay schedule (weekly, biweekly, semimonthly, monthly) and the first pay date with you.
- Business bank account details for payroll funding, typically a voided check or bank letter.
- Benefit and deduction details — retirement plan contributions, other pre-tax or after-tax deductions, and any wage garnishment orders.
- Workers' compensation policy information, if your setup includes it.
If switching providers mid-year
- Payroll registers for the year to date, or a year-to-date summary for each employee.
- Quarterly federal payroll returns (Form 941) filed so far this year.
- State quarterly withholding and unemployment returns filed so far this year.
- Prior-year Form 940 and W-2/W-3 copies, for reference.
- Payroll tax deposit history, so deposits and filings can be reconciled.
Documents for each employee
- Form W-4 (federal withholding) and the state withholding form, where the state has one.
- Direct deposit authorization with bank details, if paid by direct deposit.
- Pay rate and status — hourly or salary, exempt or non-exempt, hire date, and job title.
- Full legal name, address, and taxpayer ID as they should appear on the W-2.
Form I-9 is generally kept on file by the employer rather than sent to the payroll provider. Follow your engagement and the employer's policy on whether you handle it.
Contractors
- Form W-9 from each contractor, so 1099s can be issued at year-end.
- A list of contractors paid so far this year with amounts, if you are taking over mid-year.
Why payroll setup stalls
- State account numbers are buried in old mail, and new businesses may not have registered yet.
- Employee forms depend on each employee, so the owner is waiting on several people at once.
- The old provider has the history, and reports have to be exported before access ends.
- The first pay date doesn't move, so every missing item adds pressure.
A simple setup process
- Send one request to the owner for the business items, with a due date well before the first pay date.
- Make each state or account its own item so a missing number is obvious.
- Mark mid-year items optional for brand-new employers, so they can be marked N/A.
- Send a separate request for each employee's forms if the owner prefers employees upload directly, or let the owner collect and upload them.
- Let reminders run and check progress on the dashboard.
How FilesDue handles this
Build a payroll setup checklist from the items above, or start from the Bookkeeping onboarding template (which includes Business formation docs, bank statements, and an optional Payroll reports item) and add items like “State unemployment rate notice” and “Form 941 (Q1–Q3).” To send employee requests in one go, paste a CSV with each name and email (plus optional template, title, due date, and note), up to 50 rows per batch, within your plan's active-request limit.
Each person gets one upload link and doesn't need an account. Reminders go out on day 2, 5, and 9 after you create the request, then weekly, and each one lists only what is still missing. If a form is unreadable or unsigned, send the item back with a short reason and the person is asked for a new file.
Tips for payroll onboarding
- Ask for state notices as scans or PDFs, so the account number and rate can be checked against the source.
- Ask the old provider's reports to be exported as PDFs before the client loses access.
- Set the due date at least one full pay period before the first payroll you will run.
- Keep an optional “Other payroll notices” item for letters from tax agencies.
Frequently asked questions
Do employees need an account to upload? No. They use the link you send.
What does it cost? Solo is $15/mo with 25 active requests; Pro is $29/mo with no limit on active requests. See pricing.
Do you have a year-end checklist too? Yes. See the year-end bookkeeping checklist.