Knowledge Base - TaxCalc

	How do I claim relief for Research and Development from 1 April 2024? For accounting periods starting on or after 1 April 2024, the merged R&D expenditure credit (RDEC) and enhanced R&D intensive support (ERIS)...
	04 Mar, 2026 Views: 3662

	How do I enter a Research and Development Expenditure Credit (RDEC) on my CT600 - accounting periods starting before 1 Aril 2024 The research and development expenditure credit (RDEC) replaced the large company scheme in April 2016 to continue to encourage investment in...
	04 Mar, 2026 Views: 8111

	How do I use excess pension contribution allowance carried forward from previous years? TaxCalc automatically offsets your pension contribution allowance against your pension contributions for the current year. If contributions have...
	04 Mar, 2026 Views: 4611

	HMRC Simple Assessments - why am I or my client receiving one? From 2025, HMRC began issuing Simple Assessment letters, which provide detailed calculations for any tax owed by customers for income received in...
	04 Mar, 2026 Views: 547

	How to enter Voluntary Class 2 NIC for Self-Employment, Partnerships and Lloyds If your profits (self-employment, Partnership and Lloyds) are less than the Small Profits Threshold, (* £6,845 for 2025/6) and you want to make...
	04 Mar, 2026 Views: 11293

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	TaxCalc Release Notes 2026 Below are the Release Notes for TaxCalc 2026 releases. Click to see the Release Notes for 2013-2019 > 2020-2024 > 2025 Please note we phase...
	13 Feb, 2026 Views: 207571

	What is a 1046 authentication error? When you receive a 1046 error message in TaxCalc (as shown above) after attempting to file tax return, it will be due to one of the following: ...
	13 May, 2025 Views: 139712

	Update to refunds made by HMRC On 1st April 2015, HMRC updated their system to change the way they allocate repayments of overpaid tax. HMRC will only process the refund using...
	14 Feb, 2023 Views: 112119

	Useful HMRC links and contact numbers Personal Tax How to pay HMRC – Different ways to pay your Income Tax or Capital Gains Tax Online Services Helpdesk – Help signing up for...
	28 Jun, 2017 Views: 107298

	How do I download TaxCalc? To download and install TaxCalc on a new computer, or update it on a computer that already uses TaxCalc, we recommend viewing our video tutorial...
	25 Oct, 2022 Views: 92623

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