Zammad's means run higher on ticketing core (6.0 to 1.0), omnichannel (6.8 to 0.3), knowledge and self-service (4.2 to 0.2), integrations (4.0 to 0.0), sovereignty (6.3 to 3.5) and pricing transparency (6.8 to 0.0); OTRS publishes no prices, and pricing was not weighted against it. The split: customer data protection (3.8 to 2.8), one judge leaning OTRS, five lean Zammad. OTRS's case there is legal posture — German contracting entity, named external data protection officer, stated retention periods — scored 2–4 on the credit those practices earn; Zammad's captures show no tenant DPA, retention period or audit log evidenced. OTRS's other scores rest on legal pages where we found no public information on queues, routing, SLAs, APIs or connectors. Weighted totals per judge run Zammad 5.3–5.6 against OTRS 0.5–2.2. Zammad's gaps: only GitHub/GitLab and Grafana/Elasticsearch named as integrations; telephony appears in no tier's channel list and carries no price.
Choose OTRS if
Your contract must sit with a German-registered vendor — OTRS's legal entity jurisdiction is DE, and the imprint names OTRS GmbH, Oberursel (Amtsgericht Frankfurt am Main HRB 143059, VAT DE453344897).
You need a named external data protection officer documented before signature — OTRS's privacy-policy captures show one.
Your compliance gate is stated retention periods in a published privacy policy — OTRS's captures state them.
Your reviewers credit data-protection practices evidenced on the vendor's own site — on customer data protection, where OTRS scores spread 2–4, one judge leaned OTRS.
Choose Zammad if
You need core ticketing evidenced — states, assignment, escalations, SLAs, macros, templates and automation rules are named in Zammad's captures; ticketing core means 6.0 to 1.0, with 6 judges leaning Zammad.
Your customers reach you on many channels — email, web form, SMS, chat, Telegram, Facebook and WhatsApp are priced per tier into a unified ticket view (omnichannel 6.8 to 0.3).
You must budget before pilot — Zammad publishes €7/€16/€25 per agent per month plus a metered €0.03 per AI call, with VAT treatment stated (pricing transparency 6.8).
Your residency requirement is EU-only — Zammad's data residency attribute reads EU only and its subprocessor exposure reads none.
You want the self-hosted option — Zammad is offered cloud or self-hosted, and its sovereignty scores of 6–7 credit that option (sovereignty means 6.3 to 3.5).
Read this comparison as one judge. Each weighs the same scores by what they care about.
The Agent Advocate
Has answered tickets for six years and judges every tool by the hundredth reply, not the first. Wants search that finds the old thread, macros that save real keystrokes, and one screen rather than four tabs. Treats agent-activity dashboards as a smell.
OTRS
Zammad
This judge's pick
Criterion by criterion
Ticketing, queues & SLA
OTRS
The evidence proves the category label — 'Customer Service & Helpdesk' on the homepage — and nothing else: no queue, no routing rule, no SLA timer, no macro, not a word on whether search reaches ticket bodies. I judge by the hundredth reply, and I can't put a routing model in front of a team that this sheet doesn't show. One point for the label, and that's charity.
Zammad
States, assignment, escalations, macros, templates, automation rules and SLAs with reporting are all on the page — but SLAs only start at Professional, and nowhere does the evidence say one word about search across ticket bodies, which is the first thing I judge. No merge/split, no business-hours policies, no per-agent resolution reporting either.
Channels in one queue
OTRS
The word 'helpdesk' is the only reason to believe email lands anywhere; no chat, phone, portal, messenger or social channel appears in any of the six captured pages. I can't even confirm one shared queue, let alone a customer switching channels mid-issue without starting over.
Zammad
Email, web form, SMS, chat, Telegram, Facebook and WhatsApp are listed per tier plus a telephony integration, and the evidence promises all communication in one structured ticket view with history — that's genuinely one queue. Docked because call logging, messenger consent handling and a requester-visible portal for their own tickets are all unevidenced, and chat/Telegram only start at Professional while messengers wait for Plus.
Knowledge base & deflection
OTRS
The only knowledge content anywhere is 'viewing FAQs' on OTRS's own website — that's their marketing, not a help centre my customers could search. No article workflow, no agent suggestions, no deflection reporting: as this sheet shows it, answers live in agents' heads and old tickets, which is the definition of the floor.
Zammad
A help centre and a knowledge base — multilingual from Plus upward — positioned explicitly for customers solving issues 'without opening a ticket'. But there's no evidence of article suggestions before submission or while answering, no review dates, no versioning, and no deflection reporting: deflection here is a claim, not a number the team can act on.
Customer data protection
OTRS
The GDPR practice on display is real but entirely about OTRS GmbH's own website: stated retention periods (trial data 3 years, emails 10 years for tax), a named external DPO, and a long subprocessor list with SCCs for the US ones. Nothing executes on the product side — no agent roles, no queue visibility, no ticket redaction, no audit of who opened which ticket, and no signable DPA confirmed in the Trust Center. The vendor polices its own cookies well; the ticket archive is silent.
Zammad
GDPR rights including deletion and portability are published, individual roles and permissions exist, and the archive sits in an ISO27001-certified German data centre with 2FA and SSL — but that's vendor posture plus coarse roles. No published DPA, no stated retention period for the ticket archive, no audit log of who opened which ticket, and nothing on attachment handling or redaction.
Integrations & API
OTRS
The only integrations named anywhere are the vendor's own marketing stack — Google Tag Manager, HubSpot, 6sense, LinkedIn pixels — which serve their ads, not my tickets. No CRM connector, no API docs, no webhooks, no SSO: as far as this sheet goes, context gets copied in by hand.
Zammad
Open APIs and 'ready-to-use integrations', but the only names on the evidence are GitHub/GitLab and Grafana/Elasticsearch — no CRM, no shop, no order management, no webhooks, SSO, SCIM or documented rate limits anywhere. Being open source with the code freely available softens the blow since I could build it myself, but inspectable is not documented.
European sovereignty
OTRS
The imprint puts the contracting entity squarely in Germany — OTRS GmbH, Oberursel, registered at Amtsgericht Frankfurt, VAT DE-numbered — and third-country processing is at least named with SCCs. But hosting for customer instances is stated nowhere (the pipeline marks residency unknown), and the published subprocessor list is website trackers, not the product chain, so I can't tell a buyer where the ticket archive would sleep. German entity gets it above the 3 anchor; unproven hosting keeps it well short of 5.
Zammad
Zammad GmbH at Marienstraße 18 Berlin, commercial register Charlottenburg HRB 163946 B, made and hosted in Germany in an ISO27001 data centre, with a self-hosted option for buyers who want the archive on their own iron — that's a chain I could defend to a customer. It falls short of 8 because no data-centre provider is named and there's no published subprocessor list for the product itself; the only subprocessors disclosed are website analytics (Matomo, Moosend), not the service chain.
Pricing transparency
OTRS
Three separate homepage captures and a full legal sweep, and not one euro figure, tier name or per-agent price appears anywhere. I can't compute an annual invoice for eight agents from what I was shown, which means every tier is a sales conversation as far as this sheet goes.
Zammad
I can compute the invoice from public pages: €7/€16/€25 per agent per month, agent caps of 5/35/unlimited, channels mapped to tiers, storage and attachment limits, support hours, even the metered AI fee of €0.03 per call, with VAT treatment stated. What keeps it under 8 is that billing period detail and minimum term aren't stated, and a 50-agent team needing WhatsApp is silently forced to the top tier by the cap alone.
Sovereignty, side by side
Dimension
OTRS
Zammad
Legal entity
Incorporated in DE
Incorporated in DE
Ownership
Not determined
Not determined
Data residency
Not determined
EU only
Subprocessors
Not determined
Not determined
Facts, side by side
Only facts both products carry under the same definition — anything else would not be a fair row.