Free, indicative tax tools from Montrogue Tax Advisors. Choose a calculator below to get started.
HMRC Tax Deadline Calendar
Interactive calendar of key HMRC filing and payment deadlines for 2026/27. Filter by sole trader, limited company, landlord, employer, VAT-registered and CIS to see the dates that apply to you.
Statutory Residence Test Calculator
Estimate your UK residence status under HMRC’s RDR3 Statutory Residence Test — automatic overseas and UK tests, plus the sufficient ties test.
Fostering Allowance Taxable Profit
Estimate the taxable profit from your fostering income using HMRC’s Qualifying Care Relief (foster carer’s relief) for 2025/26.
MTD for ITSA Enrollment
Find out if and when you must register for Making Tax Digital for Income Tax Self Assessment as a sole trader or landlord, using the £50,000, £30,000 and £20,000 qualifying income thresholds.
Foreign Income & Gains (FIG) Regime
Check whether you qualify for the new 4-year FIG regime (the replacement for the non-dom remittance basis from 6 April 2025), see how many years of relief you have remaining, and get an indicative annual UK tax-saving estimate on foreign income and gains.
R&D Tax Relief Eligibility
Check whether your company qualifies for UK R&D tax relief — the merged scheme (from 1 April 2024), the Enhanced R&D Intensive Scheme (ERIS) for loss-making R&D-intensive SMEs, or legacy SME/RDEC — with an indicative benefit estimate.
Tax Code Checker
Understand what your UK PAYE tax code means for 2025/26 — L, M, N, T and K codes, Scottish (S) and Welsh (C) prefixes, emergency W1/M1/X codes and the BR, D0, D1, NT and 0T codes — with an indicative income tax estimate if you enter your salary.
High Income Child Benefit Charge
Estimate how much Child Benefit you must pay back if the higher earner’s adjusted net income exceeds £60,000, with full clawback at £80,000, and see the extra effective marginal rate the taper creates.