Katalog firm
- Certas AG
- Certax (Brentwood)
- Certax Accountant Clacton on Sea
- Certax Accounting
- Certax Accounting
- Certax Accounting (Birmingham North & Sandwell) Limited
- Certax Accounting (Edinburgh) Ltd
- Certax Accounting Birmingham Central
- Certax Accounting Central & East Norwich Ltd
- Certax Accounting Limited
- Certax Accounting Midlands
- Certax Accounting Wirral