Who must e-file now
The IRD is phasing in mandatory e-filing of profits tax returns for corporations and unincorporated businesses, excluding sole proprietorships[1]. The first phase applies to returns for a year of assessment beginning on or after 1 April 2025, that is 2025/26 onwards, and covers the BIR51 and the BIR52[1].
An entity is caught if it is a "Part 4AA entity" of a multinational enterprise group for the matching fiscal year[1]. Those groups are the ones with annual consolidated revenue of EUR 750 million or more in at least two of the four fiscal years immediately before the tested year[2][1]. A typical owner-managed Hong Kong company is nowhere near that line.
| Taxpayer | Filing requirement |
|---|---|
| Part 4AA entity of an in-scope multinational group | Must e-file the BIR51 or BIR52, and keeps doing so in later years |
| Other corporations and partnerships | Paper, electronic or semi-electronic filing |
| Sole proprietorships | Report in the BIR60; excluded from the mandatory e-filing programme |
| Supplementary forms, any filer, years of assessment 2020/21 to 2026/27 | Must be submitted electronically as XML through the BTP or TRP |
| Voluntary e-filers | A further 1 month on application |
Once in, always in
An entity required to e-file for one year must e-file for every later year, even if it no longer meets the conditions, including when it leaves the group or the group falls out of scope[1]. Paper is still allowed in listed exceptions, such as an entity being wound up or amalgamated, one that has notified its cessation, accounts covering more than 12 months, or a 2025/26 return issued on or before 31 March 2026[1]. Even then, all required supplementary forms go in electronically[1].
Everyone else: three filing modes
For 2025/26 returns the IRD lists three modes[3]:
- Paper: the 4-page paper return, with supplementary forms uploaded as XML and supporting documents on paper[3].
- Electronic: an e-return through the Business Tax Portal (BTP) or Tax Representative Portal (TRP), with XML supplementary forms and supporting documents in iXBRL.
- Semi-electronic: everything submitted online, then a 1-page simplified return printed, signed and sent on paper. This mode is not open to entities that must e-file[3].
Corporations and partnerships can e-file returns for the years of assessment 2022/23 to 2025/26[2][5]. A paper filer who uploaded supplementary forms must print the Control List (IR1477) with its QR code, have it signed by the person who signs the return, and send it with the return[3].
Why some choose e-filing anyway
The IRD grants a further 1 month on application to a taxpayer that will e-file through the BTP, counted from the day after the block extension date or the normal due date, whichever is later. The application must reach the IRD at least 7 working days before the return is otherwise due[3]. If a paper return is filed after that extension was granted, the extension is void and the IRD may consider penalty action[3]. The IRD offers its iXBRL taxonomy package and data preparation tools free of charge for preparing the supporting documents[3].
Sole proprietors
A sole proprietor files the BIR60, which can be filed online through the eTAX Individual Tax Portal. For 2025/26, e-filing gave sole proprietors an automatic extension to 4 September 2026[6].
The IRD is extending mandatory e-filing in phases, so check its page on the current phase below before relying on this summary for a later year.