Taxcalc Error Code 35 Jun 2026

Running an older version of TaxCalc can cause handshake failures with modern security protocols (TLS).

HMRC frequently changes its API endpoints and submission schemas (e.g., for Making Tax Digital – MTD). If you are running a TaxCalc version older than 2-3 years, the software may attempt to send data in a format HMRC no longer accepts, causing a runtime error labeled as Code 35. taxcalc error code 35

Disclaimer: This article is for informational purposes. TaxCalc and IRIS are trademarks of their respective owners. Always refer to official support channels for software-specific guidance. Running an older version of TaxCalc can cause