Berlin – November 03, 2026 -- IT service providers, software companies and SaaS vendors without an ISO 27001 certification can be dropped during supplier qualification at large clients, before price, offer or references are weighed, according to Joachim Reinke, information security expert and founder of einfachISO.

Large buyers screen vendors on formal proof before negotiations begin

Corporations and larger mid-sized companies often check suppliers against formal requirements ahead of contract talks. These include insurance, data protection rules and financial indicators, and in some cases certifications. Reinke says the costliest lost contract can be one management never learns about, because the company was filtered out before selection started.

The screening matters most for vendors that process sensitive customer data or access business-critical systems. Buyers cannot audit every candidate themselves, so they rely on standardized proof such as ISO 27001, which confirms an independent review of a company's information security management system.

Certification does not prove higher security, but internal measures cannot replace it

Uncertified vendors can also run high security standards. Large clients nevertheless often demand formal evidence, because they can hardly verify internal controls. Reinke compares it to a driver's license: if the job requires one, claiming to drive well without it does not help.

Certification cannot be fast-tracked once a tender lands

The process starts with building an information security management system. That covers assigning responsibilities, assessing risks, implementing security measures and producing documentation. An internal audit, a management review and the certification procedure follow.

Duration depends on company size, existing security level and how consistently measures are implemented, and Reinke declines to give a standard timeline. A tender that demands a valid certificate within days cannot be met without prior groundwork.

Sales strategy, not only IT policy, should drive the decision

Companies serving only clients that do not ask for such proof need not start certification. Those targeting larger B2B accounts, corporate clients or demanding tenders may treat it as part of their sales infrastructure. Reinke advises executives to weigh the business opportunities that stay out of reach without the certificate, not just its costs, and to ask what future customers will require.