Labour at an automobile maintenance shop (certified / designated shops): overtime, placing qualified staff, and concurrent duties

Bottom line first: The core of labour at an automobile maintenance shop is whether you can keep a maintenance supervisor and a vehicle inspector placed full-time with their working hours met, the overtime, holiday work and premium wages of the mechanics, and the shifts for the busy periods when vehicle inspections concentrate. The maintenance supervisor is appointed from holders of a class-1 or class-2 automobile mechanic skills certificate (Ordinance for Enforcement of the Road Transport Vehicle Act, Article 62-2-2), and a designated shop (a private inspection site) also appoints a vehicle inspector. Overtime and holiday work require a 36 Agreement (Labour Standards Act, Article 36) and premium wages (Article 37); busy periods call for variable working-hours systems (Articles 32-2 and 32-4). The certification and designation applications belong to a Gyoseishoshi, the property to a real-estate agent, and tax to a tax accountant, each contracted separately as an independent business entity.

This page sets out not the certification and designation requirements themselves, but the design of working hours, staffing and social insurance needed to keep meeting them. Whether certification or designation can be obtained, and the application documents, are the area of the transport branch office and a Gyoseishoshi; this article focuses on labour.

How does placing qualified staff such as a maintenance supervisor and a vehicle inspector affect labour?

A certified shop (certification of an automobile specified-maintenance business, Road Transport Vehicle Act Article 78) places a maintenance supervisor; a designated shop (designation of a designated automobile maintenance business, Article 94-2) also places a vehicle inspector. Both are placement requirements for "at least one qualified person", and for labour the question is whether that person is full-time with working hours met, and whether the team breaks down if they are absent.

Qualified staff	Basis and requirement for appointment	Labour point to watch
Maintenance supervisor	Appointed per business site from a person who passed the class-1 or class-2 automobile mechanic skills certificate and engages in specified maintenance (Ordinance for Enforcement of the Road Transport Vehicle Act, Article 62-2-2); legal training and technical training apply	If lost to resignation or leave, the certification's basis is affected. Tends toward long hours by also supervising the actual maintenance and the records
Vehicle inspector	Appointed at a designated shop, issues the certificate of conformity to safety standards based on the in-shop inspection (Article 94-4 etc.)	Bears the final responsibility for the inspection; continuity of duty and grasping working hours are especially important

What matters first for labour is stable employment and shifts that keep qualified staff full-time with their hours met. A structure with only one qualified person collapses its premise when that person takes paid leave, falls ill or resigns, so training a substitute qualified person and designing the duty roster are labour tasks. Where a maintenance supervisor doubles as the shop manager and handles the actual work and the supervision of juniors, whether they are a manager/supervisor under Labour Standards Act Article 41(2) becomes an issue, judged by the actual working reality, not the job title. The line for managers/supervisors is set out in Manager/supervisor or a manager in name only. Whether a qualified person can be appointed, and the judgement of the certification and designation requirements themselves, are the work of the transport branch office and a Gyoseishoshi, governed by a different law from Shakai Hoken Roumushi work.

How do you manage the mechanics' overtime, holiday work and premium wages?

To have mechanics work beyond statutory working hours (8 hours a day, 40 a week) or on a statutory holiday, you must conclude a labour-management agreement on overtime and holiday work (a 36 Agreement) and file it with the head of the Labour Standards Inspection Office (Labour Standards Act Article 36). The limit hours are in principle 45 a month and 360 a year; even with a special clause you cannot exceed 720 hours a year, an average of 80 hours (including holiday work) over several months, under 100 hours in a single month, and may exceed 45 hours a month only 6 times a year. Premium-wage rates are as follows.

Category	Premium rate (Labour Standards Act Article 37)
Overtime (over statutory hours)	25% or more
Overtime exceeding 60 hours a month	50% or more (applied to SMEs too from 1 April 2023)
Night work (in principle 22:00–05:00)	25% or more (added if it overlaps overtime)
Holiday work (statutory holiday)	35% or more

The maintenance industry is not among the industries subject to the special overtime-cap rule for vehicle drivers (such as the 960-hours-a-year frame applied from April 2024); the principal cap applies as it is. The design of the 36 Agreement's limit hours and special clause is set out in How far can a 36 Agreement allow overtime. The actual application to working hours (whether standby time, travel time and training time count as working hours) can differ by individual circumstances (unverified).

What can you use for busy-period (concentrated inspections, year-end) shifts (variable working hours)?

Vehicle inspections concentrate at month-end and year-end (March), an industry with a large gap between busy and slack. A variable working-hours system allots longer scheduled hours in busy periods and shorter in slack periods, keeping the average within 40 hours a week.

System	Basis	Where it fits
Monthly variable working hours	Labour Standards Act Article 32-2	When there are peaks within a month, such as month-end inspection concentration. Set in work rules or a labour-management agreement
Yearly variable working hours	Labour Standards Act Article 32-4	When there are peaks across a year, such as a spike at the March year-end. A labour-management agreement and filing are required

If you adopt yearly variable working hours, even a worksite with fewer than 10 regular workers cannot use the 44-hour-a-week special rule and calculates on 40 hours a week, with limits on working days, consecutive working days and daily/weekly hours over the target period. Choosing a system is set out in Choosing variable working hours and flextime. Which system fits your busy-and-slack pattern turns on the wave of orders and how the roster is built.

When do part-time and short-hour mechanics need social insurance?

Even a part-time mechanic or pit worker becomes an insured person under health insurance and employees' pension insurance if their weekly scheduled working hours and monthly scheduled working days are three-quarters or more of a regular worker at the same establishment. A short-hour worker below this three-quarters still joins if they meet the requirements of the expanded coverage for short-hour workers.

Category	Guide to joining
Three-quarters rule	Insured if weekly scheduled hours and monthly scheduled days are three-quarters or more of a regular worker
Expanded coverage for short-hour workers	At a specified covered establishment with more than 51 insured persons on a constant basis, insured if weekly scheduled hours are 20 or more, monthly wage is 88,000 yen or more, employment is expected for over 2 months, and the person is not a student (expanded to 51+ employees from October 2024)

The idea of social insurance for short-hour workers is in Social insurance for short-hour workers and the three-quarters rule, and the course of expanded coverage in How far will the expansion of social-insurance coverage go. Judging the insured status of a part-timer whose hours rise only in busy periods can differ where the contractual scheduled hours and the reality diverge (unverified). For the social insurance and special workers'-accident enrolment of field-type industries such as construction, see also Social insurance in construction and special workers'-accident enrolment for sole proprietors.

What should you watch in the link between maintaining certification/designation and labour management?

Certification and designation rest on placing qualified staff, equipment and a management structure. A labour failure becomes a risk to maintaining the certification and designation. Points to watch:

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• A one-person structure for the maintenance supervisor or vehicle inspector collapses its premise if that person resigns or is away long-term. Train a substitute qualified person and leave no gap in the roster
• Turnover from long hours links directly to a shortage of qualified staff. Put the 36 Agreement, variable working hours and premium wages in order and grasp working hours
• Work rules are mandatory to prepare and file at 10 or more regular workers (Labour Standards Act Article 89). Put the qualified staff's concurrent duties, allowances and work forms into the rules. The duty is set out in From how many employees are work rules mandatory

Who handles each procedure differs with the qualification.

Procedure	In charge
Judging the certification/designation requirements, certification and designation applications to the transport branch office	Gyoseishoshi (四葉行政書士事務所, a business entity independent of this office)
36 Agreement, work rules, variable working hours, social insurance, working-hour management	Shakai Hoken Roumushi (四葉社会保険労務士事務所)
Confirming the use district, floor area and frontage road of the shop property	Real-estate agent
Tax and depreciation	Tax accountant

四葉社会保険労務士事務所 accepts labour work as an independent business entity, and where another professional such as a Gyoseishoshi (四葉行政書士事務所) or a real-estate agent is needed, we introduce them under a contract you conclude directly, separately. This office takes no referral fee.

What can 四葉社会保険労務士事務所 do?

What this office takes on is the design of labour so a certified or designated shop can employ mechanics stably while maintaining certification and designation.

• Preparing the employment contracts, rosters and working-hour management that support the continuity of the maintenance supervisor's and vehicle inspector's duty
• Preparing and filing the 36 Agreement, and designing premium wages for overtime, holiday, night and over-60-hours-a-month work
• Designing monthly and yearly variable working-hours systems matched to the inspection concentration and year-end
• The social-insurance acquisition and loss of status for part-time and short-hour mechanics, and confirming the expanded-coverage requirements
• Preparing work rules, wage rules and notice of working conditions

The certification and designation applications belong to a Gyoseishoshi, the shop property to a real-estate agent, and tax to a tax accountant. 四葉社会保険労務士事務所 accepts work as an independent business entity, and where another professional is needed, we introduce them under a contract you conclude directly, separately. There is no referral fee.

Consultations are free of charge. Fees are set out in the fee schedule; see also our services and how a consultation proceeds.

Frequently asked questions

Q. What qualification does a maintenance supervisor need?
A. Per business site, you appoint a person who has passed the class-1 or class-2 automobile mechanic skills certificate and engages in specified maintenance (Ordinance for Enforcement of the Road Transport Vehicle Act, Article 62-2-2). The appointment is notified with a document proving the pass. After appointment, legal training and technical training are required. A one-person maintenance-supervisor structure collapses its premise if that person leaves, so training a substitute qualified person and designing the roster are labour tasks.

Q. How much is the premium wage for mechanics' overtime?
A. Overtime is 25% or more, overtime exceeding 60 hours a month is 50% or more (SMEs too from 1 April 2023), night work is 25% or more, and work on a statutory holiday is 35% or more (Labour Standards Act Article 37). Overtime beyond statutory hours and holiday work require concluding a 36 Agreement and filing it with the head of the Labour Standards Inspection Office (Article 36). The maintenance industry is not subject to the special cap for vehicle drivers; the principal cap applies.

Q. How can you legally build the long hours during the inspection-concentration period?
A. Use a variable working-hours system that allots longer scheduled hours in busy periods and shorter in slack periods, keeping the average within 40 hours a week. Month-end inspection concentration fits the monthly system (Labour Standards Act Article 32-2); a spike at the March year-end fits the yearly system (Article 32-4). The yearly system cannot use the 44-hour-a-week special rule and calculates on 40 hours a week, with limits on working days and consecutive working days. Which system fits turns on the wave of orders and how the roster is built.

Q. When do pit-worker part-timers need social insurance?
A. If weekly scheduled hours and monthly scheduled days are three-quarters or more of a regular worker, they become insured under health and employees' pension insurance. Even below three-quarters, they join if, at a specified covered establishment with more than 51 insured persons on a constant basis, they meet 20+ weekly hours, a monthly wage of 88,000 yen or more, employment expected over 2 months, and not being a student (expanded to 51+ employees from October 2024). Judgement where hours rise only in busy periods differs by individual circumstances.

Basis for this article

• Road Transport Vehicle Act (Act No. 185 of 1951) Article 78 — certification of an automobile specified-maintenance business (certified shop). The amendment enforced on 1 April 2020 (Reiwa 2) expanded the former "disassembly maintenance" into "specified maintenance", which includes electronic-control-device maintenance
• Road Transport Vehicle Act Article 94-2 — designation of a designated automobile maintenance business (designated shop / private inspection site). A designated shop can issue the certificate of conformity to safety standards through a vehicle inspector based on the in-shop inspection (Article 94-4 etc.)
• Ordinance for Enforcement of the Road Transport Vehicle Act (Ordinance of the Ministry of Transport No. 74 of 1951) Article 62-2-2 — matters to be observed by an automobile specified-maintenance business. Per business site, a maintenance supervisor is appointed from a holder of the class-1 or class-2 automobile mechanic skills certificate who engages in specified maintenance, to supervise the specified maintenance and the records. The maintenance supervisor has legal training and technical training (Ministry of Land, Infrastructure, Transport and Tourism / regional transport bureau maintenance-supervisor training materials, accessed 1 October 2026)
• Labour Standards Act (Act No. 49 of 1947) Articles 32-2 (monthly variable working hours), 32-4 (yearly variable working hours), 36 (overtime and holiday work), 37 (premium wages for overtime, holiday and night work), 41(2) (managers/supervisors) and 89 (duty to prepare and file work rules)
• The overtime cap (in principle 45 hours a month, 360 a year; even with a special clause within 720 hours a year, an average of 80 hours over several months, under 100 hours in a single month, exceeding 45 hours a month only 6 times a year) applies from April 2019 for large firms and April 2020 for SMEs. The 50%-or-more premium for over-60-hours-a-month overtime applies to SMEs too from 1 April 2023 (Ministry of Health, Labour and Welfare materials on the overtime cap and the raised premium for over-60-hours overtime, accessed 1 October 2026)
• Health Insurance Act (Act No. 70 of 1922) and Employees' Pension Insurance Act (Act No. 115 of 1954) — the three-quarters rule and the expanded coverage for short-hour workers (at a specified covered establishment with more than 51 insured persons on a constant basis: 20+ weekly hours, monthly wage of 88,000 yen or more, employment expected over 2 months, not a student; expanded to 51+ employees from October 2024. Japan Pension Service "Expansion of social-insurance coverage", accessed 1 October 2026)
• The actual application to working hours (treatment of standby, travel and training time), the choice of a variable working-hours system, and the judgement of insured status for short-hour workers differ by the individual working reality. This article does not conclude on the individual case (unverified)

This article is general information. Individual determinations are made by a qualified professional after a consultation, in light of individual circumstances. 四葉社会保険労務士事務所 can advise on the employment contracts, rosters and working-hour management that support the continuity of the maintenance supervisor's and vehicle inspector's duty, the design of the 36 Agreement and premium wages, variable working hours matched to inspection concentration and year-end, the social insurance and expanded-coverage requirements for part-time and short-hour mechanics, and preparing work rules and wage rules. The certification and designation applications are handled by a Gyoseishoshi (四葉行政書士事務所), the shop property by a real-estate agent, and tax by a tax accountant. 四葉社会保険労務士事務所 accepts work as an independent business entity, and where another professional is needed, we introduce them under a contract you conclude directly, separately; there is no referral fee. Frequently asked questions are collected in the FAQ. Written by Joji Uramatsu (Shakai Hoken Roumushi, Gyoseishoshi, Registered Real Estate Transaction Specialist).