Two separate things, happening at once
The first is arithmetic: a first paycheck usually covers a partial pay period, because you started partway through one. If the period runs the 1st to the 15th and you started on the 8th, you are paid for eight days, not fifteen.
The second is structural: deductions do not shrink in proportion. A percentage deduction scales with your gross, but a fixed one does not — and a one-off deduction hits a small paycheck far harder than a full one. Together they can turn a paycheck you expected to be $3,650 into $1,509.
The same job, two paychecks
A $5,000 monthly gross, a 22-working-day period, 22% income tax, 5% pension, and one one-off equipment deduction of $150 in the first cycle:
| Line | Full period | First period (10 of 22 days) |
|---|---|---|
| Gross pay | $5,000 | $2,273 |
| Income tax (22%) | −$1,100 | −$500 |
| Pension (5%) | −$250 | −$114 |
| One-off equipment | — | −$150 |
| Net pay | $3,650 | $1,509 |
The first paycheck is 41% of a normal one. Roughly 45% of that gap is the partial period, and the rest is the one-off deduction landing on a smaller base. Neither is an error, and only one of them is permanent.
Which part is actually lost
The unpaid days are not lost — you simply had not worked them yet when the period closed. They appear in the next cycle, which is why the second paycheck is often slightly larger than a normal one.
What is gone is any genuine one-off: equipment, uniform, a training fee, or a recovery for leave you had not accrued. Those are worth checking line by line, because they are the only part of the gap that does not come back.
Why the tax percentage looks wrong
Tax is withheld per paycheck, not recalculated annually. A partial period produces a smaller gross, which can fall into a different withholding band than your normal pay — so the effective percentage on a first payslip can be higher or lower than it will be later.
This usually evens out across the year. It only becomes a real problem if the withholding assumption is wrong for your actual annual pay, which shows up as a surprise at tax time rather than in month one.
Where the cycle fits in
How big the partial period is depends entirely on your pay cycle. On a weekly cycle the worst case is six days short; on a monthly cycle it can be three weeks. That is one more reason the pay period structure matters more than people expect — the same start date produces very different first paychecks depending on the cycle.
What to check on the payslip
- The period dates. Confirm which days the payment covers. This single line explains most of the gap.
- One-off deductions. Anything labelled equipment, uniform, advance or recovery is a genuine reduction, not a timing effect.
- The hourly rate used. If the payslip implies a rate, compare it to your real one — the arithmetic is in what an hour is worth.
- Whether breaks were treated as unpaid. A payslip that pays you for break time will disagree with your own record; see are lunch breaks paid.
Once you know your payday, the paycheck countdown turns the wait into a number of days, hours and shifts. The full topic — all four cycles and the biweekly drift — is when the money arrives.