From June 1, 2022, there has been some changes in the required documents for permanent residence applications from work visas such as "Engineer/Humanities/International Services". Tax certificates and residence certificates are no longer required for guarantors of permanent residence applications.
Until now, when asking your friend or acquaintance to be a guarantor for permanent residence status, a tax payment certificate and certificate of residence containing private information such as income was required, which was a psychological obstacle for many people. Compared to before, the number of required documents for the applicant himself/herself has increased overall, but for the guarantor, the documents have become less of a burden.