Knowledge Base - TaxCalc

	Known issues in the latest released version of TaxCalc Below is a list of notable issues that have been reported in recent versions of TaxCalc since their release. Other issues may exist that have not...
	02 Apr, 2026 Views: 50083

	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...
	27 Mar, 2026 Views: 209990

	How do I increase/decrease my payments on account towards the following tax year? You can't increase payments on account towards the following tax year – you can only reduce them. You can choose to pay more on account, but HMRC...
	27 Mar, 2026 Views: 24876

	How much tax will I need to pay in January? The information you provide within the SA302 calculation will determine how much tax is due. This calculation will then apply any tax already...
	26 Mar, 2026 Views: 3238

	How do I complete the CT600 for a long period of accounts? (Business users) If your accounts cover a period of more than 12 months, you'll need to complete the CT600 for two periods, as follows: Prepare the accounts for...
	26 Mar, 2026 Views: 10030

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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...
	27 Mar, 2026 Views: 209990

	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: 140119

	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: 112302

	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: 108054

	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: 94524

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