HMRC has provided a method of sending information relevant to the completion of a Tax Return called Application Program Interfaces or APIs. This is the first part of their overall Digital transformation project known as Making Tax Digital.
This allows TaxCalc to request information held by HMRC and pull it into the SA100 Tax Return. HMRC APIs provide the following information:
Please note that if no information is received but should be received or the information is incorrect then it is likely that HMRC do not have the correct records relating to the individual taxpayer. Please ensure that you check the documentation received and make any corrections necessary before submitting the Tax Return to HMRC.
The data on HMRC's system is available for use within the API function for approximately 2 years. If you were trying to use the fetch facility for returns from 2021 or before, this is likely to return an error and the details would need to be manually entered on the return. If the taxpayer holds a Personal Tax Account then details can be obtained via this method which may encompass details going back to 2017.