January 15, 2026
South Korean Tax Season Timeline for Cold Wallet Holders
Key dates and documentation windows in 2026
South Korean individual income tax filing for the prior calendar year typically opens in late May, but preparers begin requesting documentation months earlier. Cold wallet holders who wait until April often discover that assembly timelines conflict with preparer intake deadlines.
January: ideal assembly start
Most assembly engagements begin in January when holders have closed the prior calendar year mentally and can list wallet activity with reasonable completeness. Two to four weeks of assembly time fits comfortably before preparer document requests arrive in late February.
January intake also leaves room for gap resolution when exports are incomplete. On-chain tracing for missing entries rarely completes in under a week when address derivation paths are complex.
February: preparer coordination
Accountants and tax offices begin requesting transaction documentation in February. Holders with assembled reference logs can respond immediately. Holders still gathering exports enter queue backlogs at assembly practices — including ours — where February volume typically doubles January volume.
If your preparer asks for specific column formats, communicate those requirements during intake rather than after draft delivery. Reformatting is faster than reassembly.
March: rush constraints
March requests are accepted when capacity allows, but rush engagements may skip optional review stages. Missing exports discovered in March rarely resolve before filing support deadlines without accepting documented ambiguities in the final package.
Cross-border holders
U.S. citizens and other expatriates in South Korea often face parallel documentation requests. Begin assembly once you know both jurisdictions’ reporting years align on the same transaction set. Dual-format deliverables require additional normalization time — budget an extra week.
Practical recommendation
Schedule intake in the first half of January. Deliver exports within three business days of the intake call. Review draft logs within five business days of receipt. This rhythm matches what most Incheon-area preparers expect when supporting cold storage clients.