Self-Assessment pre-population API

Members may have heard that HMRC is trialling a new Self-Assessment pre-population API which will enable agents to download from HMRC information about their clients’ employment and pension income based on RTI data into their SA software. A recent article about this appeared on AccountingWeb

HMRC has provided us with the following update:

API Update

  • We are running a small-scale trial of an improved SA Pre-Population API.
  • The improvements are based on feedback from software providers, tax agents and VCG members and include things like: PAYE data in April, not September; private pensions by provider; private pensions not as employments; state pension; tax-free allowances.
  • Around ten software providers are involved.
  • We have released a "sandbox" test service to the software providers and some of them are actively developing changes to their software to use the new API.
  • We hope to put the small-scale trial into production in December, but this is not guaranteed.
  • In the small-scale trial, software providers will make the new API available to a small subset of their end users. The majority of users will remain on the existing version of the API for the upcoming SA peak.
  • We do not yet have a date for when the service will exit the trial and go fully live. The AccountingWeb article suggests we will go live from April 6th 2019 but this date hasn't come from us.
  • The private trial doesn't include integration with the new agent services account. We are hoping to add this but it isn't confirmed.

If you have any comments or queries relating to the above, please contact us at atttechnical [at]

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