How MI5, MI6 and GCHQ compare as UK intelligence employers: remit, sites, vetting, pay transparency and eligibility, plus which one actually fits your background.
The three agencies split by function, not seniority: MI5 handles domestic security, MI6 gathers intelligence overseas, and GCHQ covers signals intelligence and cyber. All three require British citizenship and DV clearance, and since November 2022 none of them require a British parent, a rule that’s still quoted as current in a lot of other guidance.
How the three agencies compare
| MI5 | MI6 | GCHQ | |
|---|---|---|---|
| Remit | Domestic security | Overseas human intelligence | Signals intelligence, cyber |
| Main UK base | London | London | Cheltenham |
| Other sites | Regional presence | None published | Bude, Manchester |
| Published starting salary | £40,428 (IODP) | Not published | Not published |
| Typical process length | 6–9 months (up to 12 for IODP) | 6 months to 12 months, by role | 6–9 months |
| Standard clearance | DV | DV | DV |
MI6 and GCHQ don’t publish a headline salary the way MI5 does through its IODP programme; see each guide below for what’s known and from where.
What’s identical across all three
Eligibility is now unified. British citizenship is required (dual nationality is fine if one component is British), the parental nationality rule was dropped by all three agencies in the same November 2022 announcement, and UK residency requirements sit at roughly seven of the last ten years across the board. Discretion norms are also shared: none of the three want you discussing your application widely, all recommend a separate, non-identifying email address, and all three publish a position on using AI during the application process, optional for preparation, prohibited during live interviews and assessments.
What actually differs
Pay transparency is the clearest gap. MI5 publishes a specific figure for its flagship graduate route; MI6 and GCHQ don’t publish anything beyond “dependent on experience” or civil service grading, which means third-party estimates for those two carry more uncertainty. Site footprint differs too: MI5 and MI6 are effectively London-based, while GCHQ’s centre of gravity is Cheltenham, with a different regional presence. And the work itself is a different shape entirely: MI6’s Intelligence Officer route is built around recruiting and running human sources, GCHQ’s technical roles are assessed against the same DDaT framework used across UK government technology jobs, and MI5’s rotation model moves staff across different national security threats over a career rather than one fixed specialism.
Which one actually fits your background?
If your interest is investigative work inside the UK, MI5’s IODP is the most clearly signposted route in, and it’s the only one of the three with a published starting salary to plan around. If you’re drawn to human intelligence and want to work overseas, MI6’s Case Officer track is the direct equivalent, though be ready for a process that can run close to a year. If your background is technical, software engineering, data, cyber, GCHQ is the most natural fit, and its DDaT-aligned technical assessment gives you a concrete standard to prepare against rather than an unknown bar. All three also run corporate, trades and business-support roles, HR, finance, project management, procurement, for candidates who want to work in national security without an operational or technical role specifically.
Where to go next
Full guides for each: MI5 careers, MI6 careers, and GCHQ careers. For what DV clearance actually involves, see our guides to DV clearance and UK security clearance levels explained.