One Sign Pte. Ltd. · Singapore
We build software, run business email and websites, and supply the certificates that keep them trusted. One team, based in Singapore, that you can call when something needs fixing.
Lead service
Private, managed mail hosting for companies that want their mail under their own name and in a region they choose. We set up the mailboxes, the filtering and the DNS records, move your existing mail across, and stay responsible for it afterwards.
Need more than mailboxes? We also run dedicated mail servers and mail apps under your own company brand. Custom mail services
Services
Most clients start with one of these and add others over time. Each links to a page describing what is included and how we work on it.
Mailboxes on your own domain with webmail, IMAP/SMTP and mobile access, migrated and supported by us.
Read moreInbound filtering for spam, phishing and malware, with sender authentication set up correctly.
Read moreWindows applications, background services and integrations between the systems you already run.
Read morePortals, internal tools and customer-facing applications that run in the browser.
Read moreCompany websites that are clear, fast and easy to keep up to date.
Read moreManaged hosting for websites and applications, with certificates, backups and updates looked after.
Read moreRegistration, renewal and transfer of domains, with the DNS records for your email, website and SSL set up correctly.
Read moreAssistants, document processing and automation built into your business systems, with review steps where they matter.
Read moreCloud PBX and call centre with numbers, extensions, IVR, queues and recording, plus AI voice agents that answer and route calls.
Read moreDV, OV and EV, wildcard and multi-domain certificates from GlobalSign and Sectigo, including our One Sign–branded issuing CA.
Read moreCertificates for signing Windows software and PDF documents, delivered on hardware tokens where CA policy requires it.
Read moreOneSigner, our own software for signing PDFs and Windows code automatically with USB hardware tokens.
Read moreSupport for foreign companies researching, entering or investing in the Vietnamese market, with our partner company in Vietnam.
Read moreVietnam Desk
For foreign companies that want to research, enter or invest in Vietnam. With our partner company in Vietnam we provide market briefings, find and check local partners, arrange meetings and site visits, and introduce you to licensed law and accounting firms for the formal work.
Products
Alongside client work we develop and maintain our own products. They have their own site at onesign.sg.
onesign.sg
A Windows service and API that automates PDF signing and Windows code signing with the USB hardware tokens a company already owns: YubiKey, SafeNet, ePass and similar. Private keys stay on the token; files stay on your own infrastructure.
How we work
Whether the job is a mail migration or a new application, the sequence is the same, and the people who scope it are the people who deliver it.
We look at what you run today, what is not working, and what a good result would be for you.
A written scope with what is included, what is not, the timeline and the cost, before any work starts.
We build or set up in stages you can check, and move live systems only when you have agreed the change.
After handover we stay responsible: updates, renewals, questions and fixes go to the same team.
Company
One Sign Pte. Ltd. is a technology company incorporated in Singapore in 2019. We started as a certificate provider and reseller of SSL/TLS, code-signing and document-signing certificates, and grew into software development and hosting for the businesses we were already serving.
Our signing product, OneSigner, came out of that certificate work: customers kept asking for a way to use the hardware tokens they already owned in automated systems.
Contact
Write to us with a short description of what you run today and what you want to change. We reply with questions or a proposal, usually by email first and a call if it helps.
Existing clients can raise support tickets in the client portal.