Add our free CIS calculators to your site

Free, mobile-friendly and always kept current with UK CIS rules. If you advise or write for construction workers and contractors, drop any of these into your own pages with a single line of HTML. We keep them up to date; you keep your readers on your site.

Built for construction trade associations, contractor bodies, payroll providers, and industry blogs. The only condition is that you leave the small “Powered by Trade Tax Specialists” line in place.

How to embed (2 steps)

1. Paste the calculator. Copy the iframe snippet for the calculator you want and paste it into your page where you want it to appear.
2. Add the resize script once. Paste the small script below anywhere on the same page. It lets each calculator grow or shrink to fit its content, so there is no awkward scrollbar.

Resize script (add once per page)

<!-- Add once, anywhere on the page. Lets the calculators resize to fit. -->
<script>
window.addEventListener("message", function (e) {
  if (e.data && e.data.type === "cis-embed-height") {
    document
      .querySelectorAll('iframe[src*="www.tradetaxspecialists.co.uk/embed/"]')
      .forEach(function (f) { f.style.height = e.data.height + "px"; });
  }
});
</script>

The calculators

CIS Deduction Calculator

Preview the full page →

Work out the CIS deduction, net payment to your subcontractor, and HMRC remittance for any CIS payment.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-deduction-calculator"
  title="CIS Deduction Calculator by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="640"
  loading="lazy"
></iframe>

CIS Gross Payment Status Eligibility Checker

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Check whether you qualify for CIS Gross Payment Status and eliminate the 20% deduction from your payments entirely.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-gps-eligibility-checker"
  title="CIS Gross Payment Status Eligibility Checker by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="680"
  loading="lazy"
></iframe>

CIS Refund Estimator

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Estimate your annual CIS tax refund. See how much HMRC owes you after deductions, expenses and your personal allowance.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-refund-estimator"
  title="CIS Refund Estimator by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="680"
  loading="lazy"
></iframe>

CIS Self-Assessment Annual Calculator

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Calculate your annual Self Assessment tax liability as a CIS subcontractor and see whether you are owed a refund or have tax to pay.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-self-assessment-calculator"
  title="CIS Self-Assessment Annual Calculator by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="720"
  loading="lazy"
></iframe>

CIS Take-Home Pay Calculator

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See your net pay from a single invoice after CIS deduction, with a full breakdown of the labour base, deduction and annualised figures.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-take-home-calculator"
  title="CIS Take-Home Pay Calculator by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="620"
  loading="lazy"
></iframe>

CIS Invoice Splitter

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Split a CIS invoice correctly: calculate the labour element, deduction base, CIS withheld, VAT position and net received from the contractor.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-invoice-splitter"
  title="CIS Invoice Splitter by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="640"
  loading="lazy"
></iframe>

CIS vs PAYE Comparison Calculator

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See how your take-home pay compares as a CIS subcontractor versus a PAYE employee at the same gross earnings.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-vs-paye-comparison"
  title="CIS vs PAYE Comparison Calculator by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="700"
  loading="lazy"
></iframe>

CIS Back Years Tax Refund Calculator

Preview the full page →

Estimate your CIS tax refund for up to four previous tax years. HMRC allows claims going back four years from the current tax year.

Embed code

<iframe
  src="https://www.tradetaxspecialists.co.uk/embed/cis-back-years-calculator"
  title="CIS Back Years Tax Refund Calculator by Trade Tax Specialists"
  style="width:100%;border:0;"
  height="820"
  loading="lazy"
></iframe>

Want a calculator built for your audience?

If you run a construction or trade site and want a co-branded tool or a calculator tailored to your readers, we are happy to help. Get in touch and tell us what you need.

Talk to us about a partnership