What IAP does

iAP (株式会社アイエーピー) is a privately held, founder-led Japanese professional services firm headquartered in Chiyoda-ku, Tokyo, that delivers bilingual accounting, payroll, HR, tax, and cross-border M&A support primarily to foreign-affiliated companies operating in Japan and Japanese firms with international operations. The company is led by Representative Partner Shoji Matsushita (松下 省治), a US CPA whose prior senior finance roles at Sun Microsystems, Dell, and Citigroup anchor its credibility with multinational clients. All partners are bilingual in English and Japanese, with additional French and Chinese capability, and the team includes US CPAs, Japanese certified tax accountants (税理士), social insurance specialists (社労士), and MBAs.

The firm's service portfolio centers on end-to-end accounting outsourcing (daily bookkeeping through monthly closing, tax filing, and financial reporting), bilingual payroll and HR outsourcing (salary calculation, social insurance procedures, labor management, attendance tracking via the Jobcan-certified platform), international tax and foreign-affiliated accounting (US GAAP/IFRS conversion, multi-currency consolidation, English-language head-office reporting), and international M&A support (valuation, buyer identification, and cross-border transaction execution). Delivery is built on established third-party cloud and ERP systems — QuickBooks, Xero, Yayoi Accounting (弥生会計), Money Forward Cloud, and SAP — combined with on-site, remote, and hybrid staffing models and an on-demand / pay-as-you-go engagement model.

Commercially, iAP generates revenue primarily through professional services fees billed monthly (subscription model ranging from tens of thousands of yen for bookkeeping-only to ¥100,000–¥800,000+ per month for full accounting department outsourcing) and on a usage basis for US CPA, tax accountant, social insurance specialist, and MBA-level advisory work. Customer mix spans foreign multinationals (Bosch Engineering, KG and Company with 10 affiliated entities across Japan, Malaysia, Estonia, and the US), Japanese corporates, mid-market firms, and specialized verticals such as social welfare corporations. The firm is wholly owned and controlled by its founders with no disclosed external funding, has obtained Privacy Mark (Pマーク) certification in 2023, and operates as a member of the INPACT Alliance international accounting firms network.

Name

IAP

Legal name

株式会社アイエーピー

Website

https://i-ap.net

Company type

Private

Operating status

Operating

Headcount range

5,001–10,000 employees

Short description

iAP is a Tokyo-based, founder-led bilingual professional services firm providing accounting, payroll, HR, tax, and cross-border M&A outsourcing to foreign-affiliated companies in Japan and Japanese firms with international operations, staffed by US CPAs, tax accountants, and social insurance specialists.

Ownership category

akta.pro rank

Product category

Accounting & HR Outsourcing Services

NAICS

Accounting, Tax Preparation, Bookkeeping, and Payroll Services (54121)

SIC

Services-Engineering, Accounting, Research, Management (8700)

akta.pro primary industry

Benefits Deductions & Payroll Integration Administration (BPAAAHAF)

akta.pro secondary industry

Expense Management & Reimbursements Administration (BPACAIAH)

Keywords

• Accounting outsourcing
• Payroll services
• HR outsourcing
• International tax services
• Foreign company accounting

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Accounting/Bookkeeping Outsourcing: Daily bookkeeping, journal entries, accounts receivable/payable management, monthly/quarterly closing, and tax filing services provided by professional bilingual staff.
2. HR and Payroll Outsourcing: Salary calculation, social insurance procedures, labor management, and human resources administration services including attendance management.
3. International Business Support: English-language head office reporting, US GAAP/IFRS conversion, consolidated reporting package preparation, and international tax services for foreign-affiliated companies.
4. M&A Support: International BPO/outsourcing network for domestic and foreign M&A transactions including valuation, buyer identification, and deal support.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels3 records

Core offering

IAP (株式会社アイエーピー) provides outsourced accounting, payroll, HR, international tax, and cross-border M&A support to foreign-affiliated companies in Japan and Japanese companies with overseas operations. Services are delivered by a bilingual team (Japanese, English, French, and Chinese) on either retainer or on-demand engagement models, using cloud accounting platforms such as QuickBooks, Xero, Yayoi, Money Forward, and SAP to support both Japanese statutory compliance and U.S. GAAP/IFRS reporting.

Product overview

iAP (株式会社アイエーピー) is a bilingual accounting and back-office BPO firm offering a portfolio of interconnected outsourcing services primarily targeting foreign-affiliated companies in Japan and Japanese firms with international operations. The core offering is the Accounting Outsourcing Service (経理アウトソーシング), which provides end-to-end bookkeeping, month-end closing, tax filing, and financial reporting using professional accounting tools. This is paired with the International Tax/Foreign-Affiliated Accounting service (国際ビジネス・外资系経理), which extends to IFRS/US GAAP head-office reporting, multi-currency consolidation, and cross-border tax compliance — giving clients who need both Japanese statutory compliance and English-language group reporting a single team to work with. The Payroll & HR Outsourcing (給与計算アウトソーシング) and Human Resources & Labor Management Outsourcing (人事・労務管理アウトソーシング) services are closely integrated, sharing the same bilingual social insurance specialists and CPA team to offer combined payroll, social insurance, attendance management, and HR advisory from a single provider. An International M&A Support (国際M&Aサポート) service addresses cross-border transaction needs, and a Tax Filing Service and System Services sub-product provide specialized inputs into the core accounting workflow. The On-Demand Service model underpins the entire portfolio, enabling clients to engage specific services (e.g., payroll alone, accounting alone, or the full stack) on a flexible, as-needed basis rather than committing to a fixed scope.

Differentiator

Problem solved

Functional benefit

Products and services

• Accounting Outsourcing Service Outsourced bookkeeping, monthly closing, and financial statement preparation for foreign-affiliated companies in Japan and Japanese SMEs, delivered by a bilingual accounting team using cloud accounting platforms such as QuickBooks, Xero, Yayoi, Money Forward, and SAP.
• International Tax / Foreign-Affiliated Company Accounting Support International tax and accounting support for foreign-affiliated companies with a Japanese presence, including withholding tax, transfer pricing support, and cross-border reporting aligned with Japanese statutory requirements and U.S. GAAP/IFRS where applicable.
• Payroll & Social Insurance Outsourcing Outsourced payroll calculation, salary disbursement, year-end tax adjustment, and social insurance (shakai hoken) and labor insurance administration for foreign-affiliated companies and Japanese SMEs operating in Japan.
• Human Resources & Labor Management Outsourcing Outsourced HR operations and labor management support, including employment contract administration, HR policy support, and labor-issue advisory for foreign-affiliated companies and Japanese SMEs in Japan.
• International M&A Support Cross-border M&A advisory and integration support for foreign-affiliated companies in Japan and Japanese companies expanding overseas, including due diligence, accounting integration, and post-close finance setup.
• Social Welfare Corporation Accounting Support Specialized accounting and tax filing support for Japanese social welfare corporations (社会福祉法人), addressing the unique statutory accounting and reporting requirements of that sector.
• Tax Filing Service Statutory corporate and personal tax filing services for foreign-affiliated companies and Japanese SMEs, covering corporate tax returns, consumption tax, and individual income tax filings where applicable.
• System Services Implementation, configuration, and operational support for accounting and payroll systems, including cloud platforms (QuickBooks, Xero, Yayoi, Money Forward) and enterprise platforms (SAP) used by clients.

Quantifiable outcome

• No resignation risks from single-person accounting departments
• +3 more outcomes

Named customers8 records

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

Feature4 records

Partnerships

One partnership is on record.

• INPACT Alliance (International Accounting Firms Network)coreStrategic or Co-development PartnerInternational accounting firms network providing cross-border service capabilities for clients with global operations and M&A needs.

Scale indicators2 records

Recent moves6 records

Expansion highlights6 records

Regional players

• Aoba Accounting Outsourcing: Japan-focused accounting and back-office BPO serving SMEs and foreign-affiliated companies with bilingual staff. Most direct Japanese domestic comparable to iAP's core accounting outsourcing offering, though typically without iAP's deeper international tax/M&A extension.

Direct peers

• Vistra: International corporate services and BPO provider with operations in Japan offering accounting, payroll, tax compliance, and HR outsourcing for inbound foreign companies. Closely comparable to iAP's full-stack bilingual accounting/HR outsourcing model for foreign-affiliated clients.
• RGF Professional Recruitment Japan: Bilingual recruitment and BPO subsidiary of Recruit Holdings focused on placing and supporting bilingual professionals in Japan, including accounting and HR functions. Comparable to iAP in serving foreign-affiliated companies with bilingual professional staffing and outsourced accounting/payroll services.
• TMF Group: Global BPO firm providing accounting, payroll, tax, and HR services to foreign-affiliated companies across 125+ jurisdictions, with established Japan presence. Directly comparable to iAP's core offering of bilingual accounting and payroll BPO for foreign-owned entities in Japan.

Broad incumbents

• BDO Japan: Member of BDO International, providing audit, accounting, tax, and advisory services in Japan including IFRS/US GAAP conversion and foreign-affiliated client support. Comparable to iAP's international accounting and cross-border tax practice, though BDO is much larger and operates broader advisory services.
• Pasona Group: Major Japanese HR services and BPO company providing outsourced payroll, social insurance, and HR administration to international and domestic clients. Comparable to iAP's payroll and HR outsourcing service line, though Pasona is significantly larger and broader.
• Crowe Japan: Member of Crowe Global, providing audit, tax, advisory, and BPO services to foreign-affiliated and mid-market companies in Japan. Comparable to iAP on serving foreign-affiliated clients requiring bilingual accounting and US GAAP/IFRS reporting, though at a larger scale.
• HLB International Japan: Member of HLB International, providing audit, tax, and advisory services to cross-border clients in Japan. Comparable to iAP on serving foreign-affiliated clients needing bilingual advisory and cross-border accounting, though as a network rather than a single integrated BPO.
• FTI Consulting Japan: Global advisory firm providing corporate finance, restructuring, tax, and cross-border transaction support including in Japan. Comparable to iAP's International M&A Support service and international tax advisory, though FTI is much larger and diversified across advisory services.

Emerging players

• Yayoi (K.K. Yayoi): Leading Japanese cloud accounting and payroll software provider (Yayoi Accounting, Yayoi Payroll) increasingly offering bundled BPO and advisory services. Comparable to iAP on the payroll and accounting software layer; represents a competitive threat as Yayoi expands into services rather than remaining a pure software provider.

Market position

Strengths4 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• Facebookfacebook.com/IAP-Inc-112300800519034
• LinkedInlinkedin.com/company/iap

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about IAP