How this is calculated
This estimator adds together several common categories of unclaimed employment expense: uniform, tools or protective clothing not reimbursed by an employer, professional body fees and subscriptions relevant to your job, and a flat rate allowance for working from home under an employer arrangement, then applies your marginal tax rate to the total.
Tax relief on employment expenses is not a pound-for-pound refund of the cost; HMRC gives back the tax you would otherwise have paid on that amount of income, so a higher rate taxpayer recovers more from the same spending than a basic rate taxpayer.
This is different from the tax refund calculator elsewhere on this site, which reconciles an entire year's PAYE deductions against actual liability. This estimator is aimed specifically at unclaimed expense reliefs that are easy to overlook.
What typically qualifies
Uniforms and protective clothing that you must wear for work and launder yourself, professional subscriptions to bodies on HMRC's approved list, and a proportion of home costs where your employer requires you to work from home regularly, all typically qualify for relief.
Costs that would have been incurred anyway, such as normal commuting, or expenses already reimbursed by your employer, do not qualify, since relief is only available for costs incurred wholly, exclusively and necessarily for the job and not otherwise recovered.
Claiming these amounts
Claims under £2,500 for a tax year are usually made through form P87, and can typically be backdated up to four years if the expense pattern was similar in earlier years. Anyone who already files a self-assessment return should include these expenses there instead of using a separate form.
Where an employer has an approved flat rate expense agreement for a particular trade or uniform allowance, HMRC's published flat rate figure can be used instead of itemising actual laundry and replacement costs individually.
What this means for your company
Treat the result as a planning figure for the 2026/27 tax year. If it changes what you were about to do, take a director's salary, a dividend, a large asset purchase or a filing decision, check it against your own accounts first. We can review the position with you and confirm the tax treatment before you commit.
Frequently asked questions
How is expense tax relief actually paid?
It is not a direct refund of the cost. HMRC applies your marginal tax rate to the eligible expense total and either adjusts your tax code, going forward, or refunds the tax difference directly if claimed for a past year.
Can I claim work from home relief if I choose to work from home myself?
Generally no. The flat rate relief is intended for situations where your employer requires you to work from home, for example because there is no suitable office space, rather than a personal choice to work remotely.
What if my employer has already reimbursed some of these costs?
You cannot claim tax relief on costs your employer has already reimbursed, since that would effectively be relief on the same expense twice; only unreimbursed costs are eligible.
How far back can I claim these expenses?
HMRC generally allows claims for the past four tax years, so it is worth reviewing whether similar unclaimed costs applied in earlier years as well as the current one.