Payroll budget: building it and tracking variances

Quick answer. Building a reliable payroll budget means starting from headcount in full-time equivalents, applying an average salary per category, adding bonuses and employer contributions, then factoring in hires, departures, raises and seniority drift. Monthly tracking splits the variance into a headcount effect, a price effect and a structure effect.

In a service SME, payroll is almost always the largest cost item. A budget built in haste, with a flat contribution rate and no calendar of movements, often drifts by several points within the first half-year. The owner finds out at year-end, when it is too late to react. This article sets out a construction method and a monthly variance review, to turn payroll from a cost you endure into a line you steer.

Payroll is the sum of gross compensation paid plus employer contributions. Before budgeting, you need to know what you are adding up, because the figure changes noticeably depending on the scope you keep.

The weight of employer contributions deserves particular attention. It is made up of several contributions: health, capped and uncapped pension, family allowances, unemployment, AGIRC-ARRCO supplementary pension and work accidents, among others. This weight varies sharply with pay level, because the general reduction in contributions, now a degressive general reduction, heavily lightens the charges on salaries near the minimum wage. Using a single contribution rate across the whole payroll is the most common mistake we see in budgets submitted by owners.

The construction logic is bottom-up: you start from the detail of people, roll up to the masses, then project the year's movements. Here is the procedure we apply.

1. List headcount in full-time equivalents, by category and department, separating permanent, fixed-term and part-time contracts.
2. Set the average gross salary per category (employees, supervisors, managers) and add recurring bonuses and the estimated variable share.
3. Add employer contributions by salary band, accounting for the degressive general reduction on low salaries, without applying a uniform average rate.
4. Factor in expected movements: hires, departures, individual and general raises, and seniority drift, each dated to the month.
5. Phase the budget monthly along the real calendar of arrivals, departures and bonus payments.
6. Then compare actuals to budget every month, computing the overall variance before breaking it down.
7. Break the variance into effects to drive the decision: hiring, pay policy or skills mix.

Seniority drift, often forgotten#

Seniority drift, known in French payroll as GVT (glissement vieillesse technicité), is the mechanical effect of seniority and promotions on payroll. Even without a general raise being decided, the mass grows: an employee gaining a seniority step, a promotion granted, a coefficient change. Many budgets ignore it and end up in structural overrun. Seniority drift differs from the general raise, which is an employer decision, whereas drift is partly suffered.

The carry-over effect, the other trap#

A raise granted mid-year does not weigh the same the following year. The carry-over effect measures the full-year impact of a measure taken during the period. A 3 percent increase applied on 1 July costs only half a year in year N, but a full year in N+1. Ignoring the carry-over effect understates the next year's budget, even though no new decision was taken.

An overall variance between budget and actuals teaches nothing until it is broken down. Three main effects explain the variation, and each calls for a different response.

To these three effects you can add notions useful for reading variations over time: the level effect, which compares the mass at a given date, and the mass effect, which compares the cumulative total over the year. Two companies can show the same salary at year-end with very different annual masses, depending on when raises were paid.

Monthly tracking checklist#

• Reconcile the month's payroll actuals with the phased budget
• Identify the overall variance, in value and as a percentage
• Break it down into headcount, price and structure effects
• Check actual movements against planned movements
• Monitor the cost of low salaries and the general reduction
• Update the year-end projection
• Document significant variances and the related decision

In the files we follow, the quality of a payroll budget depends less on the precision of the initial calculation than on the regularity of the tracking. A rough budget reviewed every month beats a sophisticated budget never confronted with actuals. The value of monthly tracking is to turn a year-end surprise into a series of small, controlled adjustments. The role of an outsourced finance director or an accountant here is to install the rhythm and the reading grid, not just to produce a figure.

The risk most often overlooked is not a salary overrun, but the illusion of a stable contribution rate. Applying a single employer contribution percentage to the whole mass distorts both the budget and the variance analysis: a hire at the minimum wage does not cost, in contributions, the same percentage as a senior manager, because of the degressive general reduction. Until the breakdown by band is done, the price effect and the structure effect remain unreadable.

The starting support can be a simple spreadsheet, as long as it clearly separates volumes (headcount in full-time equivalents) and values (average salaries, contributions). As the scope grows, or when the owner wants to cross payroll with monthly revenue, a steering tool such as a Power BI dashboard makes the tracking more reliable and automated. The point is not the tool itself, but the ability to replay the variance breakdown without re-keying, month after month.

The general reduction in contributions has moved to a single degressive general reduction. This change alters how employer contributions are lightened on low salaries, and therefore the real cost of a hire near the minimum wage. A budget built on the previous relief logic may over- or under-estimate the cost of the hires concerned. To understand the mechanism and its thresholds, see our analyses of the single degressive general reduction and the panorama of hiring aids, which may reduce the budgeted cost of certain hires.

A service SME budgets its payroll using a flat contribution rate and forgets seniority drift. By mid-year, the variance is several points. The breakdown reveals that the headcount effect is nil (hires happened as planned), but the price effect drifts: seniority drift and two unbudgeted promotions explain most of it. The fix is not a hiring freeze, since hiring was not the cause, but the integration of drift into the year-end projection and the next budget. Without the breakdown, the owner might have wrongly suspended useful hires.