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Use supplementary pages SA103L to record income as an underwriting member of Lloyd’s on your SA100 Tax Return.
Use this technical documentation for partnership returns if you’re a software developer working with the Self Assessment online service.
Research to track the 2021 to 2022 Self Assessment advertising campaign and understand its effectiveness.
Use supplementary pages SA101 to record less common types of income, deductions and tax reliefs on your SA100 Tax Return.
Self assessment: finality and discovery.
Research into helping HM Revenue and Customs understand why some customers don’t file their Self Assessment return.
Use this technical documentation for individual returns if you're a software developer working with the Self Assessment Online service.
Use supplementary pages SA110 to record the results of your tax calculation on your SA100 Tax Return.
Individual returns technical specifications for Self Assessment Online software developers.
Pre and post evaluation of the Self Assessment campaign 2013 to 2014.
Call HMRC to order Self Assessment forms
Use supplementary pages SA102MS to record employment income on your SA100 Tax Return if you're a member of the Senedd Cymru — Welsh Parliament.
Use supplementary pages SA902 to record partnership income on the SA900 Trust and Estate Tax Return.
Use this guidance for support if you're a software developer working with the Self Assessment Online service.
Research to explore how HMRC customers are likely to respond to digital Self Assessment services and why, to inform service design.
Use supplementary pages SA102 to record employment income on your SA100 Tax Return.
Research to explore how Self Assessment customers perceived their initial correspondence from HMRC after it had begun a compliance check.
Use supplementary pages SA907 to declare charity status on the SA900 Trust and Estate Tax Return.
Use supplementary pages SA102MSP to record employment income on your SA100 Tax Return if you're a member of the Scottish Parliament.
Don’t include personal or financial information like your National Insurance number or credit card details.
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