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How to get online help with Self Assessment from HMRC by using our digital assistant, community forums, YouTube videos and online tools.
Find software suppliers for tax returns, supplementary pages and attachments.
The commercial software suppliers can submit one or more elements of the…
Register a new partnership for Self Assessment using form SA400.
If you operate as a business, find out if you need to include a COVID-19 grant or support payment on your tax return.
Use this technical documentation for partnership returns if you’re a software developer working with the Self Assessment online service.
Use this technical documentation for individual returns if you're a software developer working with the Self Assessment online service.
Use this technical documentation for individual returns if you're a software developer working with the Self Assessment Online service.
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