Sometimes the issue is not on your end at all. During peak filing periods (quarterly deadlines), HMRC’s API servers experience heavy traffic. If the server response time exceeds the timeout limit set by the TaxCalc software, the connection drops. This "timeout" is frequently logged as Error Code 35.
: Fully close TaxCalc and all background processes, then relaunch. Run as Administrator : Right-click the TaxCalc shortcut and select Run as Administrator
Sometimes the issue is not on your end at all. During peak filing periods (quarterly deadlines), HMRC’s API servers experience heavy traffic. If the server response time exceeds the timeout limit set by the TaxCalc software, the connection drops. This "timeout" is frequently logged as Error Code 35.
: Fully close TaxCalc and all background processes, then relaunch. Run as Administrator : Right-click the TaxCalc shortcut and select Run as Administrator
