Why Your First Payslip Is Smaller Than the Offer Letter

The figure in an offer letter is annual and gross. What arrives is monthly and net, and the first one is frequently lower still for reasons that correct themselves.

Gross to net involves several deductions

Income tax is deducted at source, calculated against an allowance spread across the year rather than applied only once the allowance is exhausted.

Social security contributions are separate from income tax and calculated on a different basis, which is why the two figures on a payslip do not track each other.

Pension contributions are commonly deducted too, often automatically unless actively declined, and they reduce take-home pay while increasing total compensation.

The tax code drives the number

A tax code tells the employer how much of your allowance to apply. A wrong code produces a wrong deduction, and wrong codes are common at the start of a job.

Starting without a code from a previous employer often means an emergency or temporary basis is applied, which usually deducts more than is ultimately due.

The overpayment is normally corrected automatically once the correct code arrives, with the excess repaid through a later payslip rather than separately.

The first month is often a part month

Starting mid-month means the first payslip covers only the days worked, so it is smaller for a straightforward reason unrelated to tax.

Some employers also run a cut-off several days before payday, which can push the first payment into the following month entirely.

Asking about the cut-off before starting is worth doing, because a six-week gap between last pay and first pay is a real cash flow problem for someone living alone.

Reading the payslip line by line

A payslip shows gross pay, each deduction separately, and net pay. The deductions should be checkable rather than accepted as a single total.

Year-to-date figures appear alongside, and they are what reveal whether deductions are tracking correctly across the whole year rather than in one month.

Keeping payslips matters for the same reason as keeping any record: reconstructing a year of pay without them is difficult and occasionally necessary.

Budget on net, and on the lowest month

Any budget built on the gross annual figure divided by twelve will fail, because the actual monthly amount is materially lower.

Variable elements make this worse. Overtime, bonuses and commission raise some months and should not be treated as the baseline.

Building the budget around the lowest reliable net month means every better month produces a surplus rather than every worse month producing a shortfall.