Hong Kong profits tax e-filing goes digital with the Business Tax Portal.

Hong Kong’s move towards digital tax filing has introduced new systems and requirements that many businesses are still becoming familiar with. The Inland Revenue Department (IRD) launched the Business Tax Portal (BTP) in July 2025, and mandatory e-filing of profits tax returns now applies to certain multinational groups, with broader expansion planned over the coming years. This article explains what the BTP means for businesses’ filing obligations now, and what to expect as e-filing expands.

What is the Business Tax Portal

The BTP is one of three new tax portals the IRD launched under eTAX on 22 July 2025, alongside the Individual Tax Portal (ITP) and the Tax Representative Portal (TRP). Where the ITP was built around individual taxpayers and absorbed the profiles of existing eTAX users, the BTP was designed specifically for businesses, offering a multi-user platform to handle tax return filing, business registration and other compliance matters electronically.

In practical terms, this changes how a company approaches its profits tax return. The legacy eTAX system centred on a single login tied to one user, which suited individual filers but was a poor fit for companies where several people might need to view or act on the same filing. The BTP allows multiple authorised users within one business to access tax and business registration functions under one account, with different roles and permissions assigned as needed.

Which companies e-file for 2025/26

Mandatory e-filing applies to Hong Kong entities that form part of an in-scope multinational enterprise (MNE) group. An MNE group falls into scope where its annual consolidated revenue reaches at least EUR 750 million in at least two of the four fiscal years preceding the year in question. Entities meeting this test are required to e-file their profits tax returns for the year of assessment (YA) 2025/26 onwards, regardless of where the group’s ultimate parent entity is based, and irrespective of whether the entity previously held an exemption from filing.

According to the Inland Revenue Department, the first phase of mandatory e-filing has already come into effect, and entities within its scope receive their notice to file either through the BTP message box or by other means the IRD specifies.

This requirement was introduced alongside Hong Kong’s implementation of the global minimum tax framework, which took effect for fiscal years beginning on or after 1 January 2025. Without going into the mechanics of how the global minimum tax itself is calculated, the practical consequence is that the IRD now needs standardised, machine-readable data from the largest multinational groups operating in Hong Kong, and mandatory e-filing is how that data gets delivered.

Voluntary e-filing and extension eligibility

Businesses that fall outside the mandatory population for 2025/26 can still choose to e-file through the BTP on a voluntary basis, an option that has been available since 2023. This comes with the same one-month filing extension available to mandatory e-filers, though the process differs. Businesses required to e-file mandatorily receive the extension automatically if they notified the IRD before March 2026, while voluntary e-filers need to apply for it, generally at least seven working days before the return is due.

Preparing for full mandatory e-filing

The IRD has set full-scale mandatory e-filing as its target for 2030, moving progressively from the largest businesses towards smaller entities. A second phase is expected around 2028, extending mandatory e-filing to businesses above a turnover threshold that has yet to be finalised.

For businesses not yet in mandatory scope, this signals a gradual but firm direction of travel rather than a distant possibility. Smaller businesses can use the years ahead to register for a BTP account, review how their current accounting and tax data would translate into an electronic filing format and consider voluntary e-filing as a way of testing internal processes before any mandatory deadline applies.

What this means for businesses

Hong Kong’s shift to e-filing is not a one-off system change but a multi-year transition that will eventually reach every business filing a profits tax return. The direction is set, even where dates and thresholds for smaller businesses are still being finalised. Treating e-filing readiness as a planning question now, rather than a compliance deadline to react to later, puts businesses ahead of a change that is coming regardless of pace.