Maximum Rebate
HMRC Self Assessment Specialists
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OverpaymentSense™

Check whether HMRC may owe you money from previous tax years — and prepare an organised Overpayment Relief claim pack. Built for CIS subcontractors and self-employed taxpayers.

Free refund checker Evidence prompts HMRC-ready letters No rebate, no fee
2–3 minutesto run the free refund check
£500–£1,500typical “sweet spot” claim range
20% or 30%our fee — only on rebates you receive

Run the free refund check

Answer a few questions and receive an estimated refund range. We'll then prepare and handle your claim for you.

● OverpaymentSense™ Refund Checker

Could HMRC owe you a refund?

Check whether you may be owed additional tax relief from previous returns.

Your CIS & income figures

Rough figures are fine — this is an indicative check only.

The 20% deductions taken by contractors, across the years above.
Gross self-employed income before expenses.
Optional — helps us spot under-claimed relief.
Please select at least one tax year and enter your CIS and income figures.
Estimates are indicative only and do not guarantee any refund. Figures are calculated from the information you provide using standard allowable-expense assumptions; your actual entitlement depends on your records and HMRC review.

How Maximum Rebate works

We prepare everything for you — there's nothing to file yourself. The route depends on the tax year, and you only ever pay a percentage of what you actually get back.

ELECTRONIC AMENDMENT · FASTEST

Tax Return Amendment

For recent years that can still be amended electronically with HMRC. We prepare and submit the amendment on your behalf.

  • Our fee: 20% of any rebate received
  • Typically settles in 2–4 weeks
  • You sign our secure Signaturely agreement, then we handle the amendment end to end
Start my free check
OVERPAYMENT RELIEF · BY POST

Overpayment Relief Claim

For older years that must be claimed by post under Overpayment Relief. We prepare the full claim and covering letter for you.

  • Our fee: 30% of any rebate received
  • Typically settles in around 6–7 months
  • We post the prepared claim to you; you check it, confirm it's correct, then sign and send it to HMRC
Start my free check
No rebate, no fee. Our fee only applies to money you actually receive. Every client signs our agreement before we proceed: electronic amendments are authorised via Signaturely; overpayment relief claims are prepared by us and submitted by you once you've reviewed and approved everything.
Maximum Rebate prepares your claim; HMRC reviews and decides the outcome. Timescales are typical, not guaranteed. Fees are charged only on rebates received — 20% for electronic amendments, 30% for postal overpayment relief.