A payroll integration connects your HR system, time tracking and accounting to payroll so the same data is not typed twice. Start with the employee record and approved hours, because errors there change what people are paid. Add finance posting next, and test against a real pay cycle before you go live.
Short version: decide which system owns each field, keep the pay records the law requires, run old and new side by side, and name the person who fixes failures before the pay deadline.
What should a payroll integration connect first?
Connect the employee record first. Name, pay rate, pay basis, department, location and status drive almost everything else in payroll. If a new hire or a pay change reaches payroll late, the error shows up on a paycheck.
Next, connect hours if your staff are paid hourly. Finance posting usually comes third, because it matters a great deal to the books but does not change what anyone is paid.
A sensible order for most mid-size companies looks like this:
- HR system to payroll: hires, exits, pay changes and job changes.
- Time tracking to payroll: approved hours, overtime and leave.
- Payroll to accounting: wages, taxes and deductions by cost center.
- Payroll to benefits: enrollment changes and deduction amounts.
Do these one at a time. Each one needs its own testing, and a phased rollout makes it clear which connection caused a problem.
Which system should own each payroll field?
Most payroll integration trouble comes from two systems that both think they own a field. Someone corrects an address in payroll, the HR system overwrites it that night, and the correction disappears.
We suggest writing a one-page table before anyone builds. List each field, the one system allowed to change it, the systems that only read it, and how fast a change must arrive. Include these at minimum:
- Legal name, address and tax details
- Pay rate, pay basis and effective date
- Employment status, hire date and end date
- Department, location and cost center
- The ID that links one employee across every system
That shared ID deserves extra care. Matching people by name or email breaks when someone marries or changes address. Effective dates need care too: a raise entered today for next month must not reach the current pay run.
Have HR and finance sign the table together. It is a business decision about who is responsible for what, not only a technical one.
What payroll data must your integration keep?
Your integration should never be the only copy of a pay record, and it should not lose the trail behind one. The US Department of Labor's FLSA recordkeeping fact sheet lists what covered employers must keep, including hours worked each day, total hours each workweek, the regular pay rate, overtime earnings, additions and deductions, and total wages for each pay period.
It also sets the time frames. Payroll records must be kept for at least three years, and records used to compute wages, such as time cards and wage rate tables, for two years. The IRS says to keep employment tax records for at least four years after filing the fourth quarter for the year. IRS Publication 15 lists the records that covers, such as withholding certificates and tax deposit dates.
In practice, this gives you three requirements for the build:
- Keep the history. Do not overwrite old rates or hours. Store each change with a date.
- Log every change. Record what moved, when, from which system and who approved it.
- Plan for system changes. If you replace a vendor, make sure the old records can be exported first.
State rules can add to this, so ask your payroll advisor or counsel to confirm your retention schedule. This article is general information, not legal advice.
How do you test a payroll integration before go-live?
Run the new setup side by side with your current process for at least one full pay cycle, and two if you have time. Compare the results employee by employee, not only in total. Totals can match while two people are each wrong by the same amount in opposite directions.
Build your test group from the cases most likely to break:
- A mid-period hire and a mid-period exit
- A pay raise with a future effective date
- Overtime that crosses a pay period
- An employee who works in two locations or cost centers
- A change to a deduction or benefit
Use masked data wherever you can, and limit who can see real pay data during testing. Then have finance confirm that the journal entries from a test pay run match the payroll register.
What happens when a payroll sync fails?
It will fail at some point, usually near a deadline. Decide the response now.
- Stop bad data from moving on, and hold the failed record with the reason attached.
- Alert a named person in the business, not only a shared inbox.
- Retry safely, so one change cannot be applied twice.
- Run a daily check that compares employee counts and key totals across systems.
- Write a manual fallback so payroll can still run if the connection is down on pay day.
Set the cutoff in hours before each pay run. Any change after that point should go through a person, so nothing surprising lands in a run being approved.
Should you use a connector or a custom integration?
Start by asking your payroll vendor what it already supports. Many vendors offer connectors for common HR, time and accounting systems. If one covers your fields and your rules, use it. It will usually cost less to run than custom work.
Custom work earns its cost when you have rules a connector cannot express: multiple legal entities, union pay rules, an in-house system, or a CRM or field app that feeds hours. Our guide to API integration cost explains what moves the budget. If payroll is part of a wider ERP decision, see whether SAP ERP fits a midsize company before you commit to a design.
What should you ask an integration partner?
Whether you hire us or someone else, get clear answers to these questions in writing:
- Which vendor APIs or file formats will this use, and what are their limits?
- Who can see pay data during the build, and where is it stored?
- How will you test against a real pay cycle?
- Who gets the alert when a sync fails near a pay deadline?
- Who owns the code and documentation when the project ends?
Once payroll data flows reliably, the next gain is often in the approvals around it. Our workflow automation team can help with those steps.
Frequently asked questions
It depends on the number of systems and pay rules. One standard connector can be fairly quick to set up, while several custom connections take longer. Plan the schedule around pay cycles, since you need at least one full cycle for parallel testing.
No. It removes retyping and reduces entry errors. People still approve pay runs, handle exceptions and answer employee questions, and those jobs get easier when the data is reliable.
Not always. Hires and exits should move quickly, while most other changes can run on a schedule. What matters more is that every change reaches payroll before the cutoff for the pay run.
Leaving field ownership undecided. When two systems can edit the same field, corrections get overwritten, and the error usually shows up on a paycheck. A signed ownership table prevents most of this.
Sources
- US Department of Labor, Fact Sheet #21: Recordkeeping Requirements under the FLSA
- IRS, Employment Tax Recordkeeping
- IRS, Publication 15 (Circular E), Employer's Tax Guide
Connecting payroll to your other systems?
We can review your HR, time and finance systems with you, map the fields and plan a safe rollout.
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