HMRC has said that the reason some of its GOV.UK content "does not yet fully meet the needs of specialist users" is due to the transition not yet being complete.
It also confirmed that HMRC manuals would be moving to the new portal, with a link back to the old HMRC versions.
The website transition has received criticism from accountants in regard to content quality, accessibility, navigation and many other issues.
This is something HMRC said it would be blogging about shortly on its working with tax agents blog.Some AccountingWEB members have raised concerns that some content they have come across is misleading, which could be dangerous for both agents and the general public.
HMRC's response to the question of content quality was that the mainstream, or entry level guidance, has been written by GDS and fact checked by HMRC subject experts.
"Mainstream content is regularly tested with users, and this evidence shows that in general, GOV.UK content meets the needs of most of our customers well.
"We are aware, however, that GOV.UK does not yet fully meet the needs of more specialist users - this is because transition from hmrc.gov.uk is not yet complete. We are currently migrating more detailed and specialist content, and expect that this will help to address these concerns," said a spokesperson.
But the Revenue said that where someone finds content is unsatisfactory or if something isn't working well, there is a link on every page for users to inform GOV.UK of the issue.
It did provide assurance, however, that manuals and specialist guidance and publications including tax tables' words will remain the same. However, the presentation may change.
HMRC manuals' transition has been tested with a prototype of GOV.UK manuals formet earlier this year, the spokesman said. They then invited feedback via the HMRC working with tax agents blog.
Based on this feedback, the Revenue said it is working on the next stage of development and would link back to the original manuals until they are ready to migrate to GOV.UK.