Security Clearance in the UK: What It Is and How to Get It

Many roles in UK defence, aerospace and the wider national security sector need security clearance. If you are new to the sector, or moving onto a more sensitive programme, the process can seem confusing. Here is a plain-English guide to what security clearance is, the different levels, and how you get it.

What is security clearance?

Security clearance, formally known as National Security Vetting, is a set of background checks that gives an organisation confidence that someone can be trusted with access to sensitive information, assets or sites. Most vetting is carried out by United Kingdom Security Vetting (UKSV), part of the Cabinet Office, although some organisations carry out their own.

The level of clearance needed is set by the organisation responsible for the role, based on what the person will have access to. Clearance is linked to a role and a sponsor, rather than being a qualification you hold in your own right.

The main levels of clearance

Baseline Personnel Security Standard (BPSS). Not a formal clearance, but the foundation for all the others. It covers your identity, right to work in the UK, employment history and unspent criminal convictions. Most roles in the sector need it as a minimum.

Counter Terrorist Check (CTC). For roles close to public figures at risk, with access to information of value to terrorists, or with unescorted access to certain establishments. It adds a security questionnaire and checks against criminal and Security Service records.

Security Check (SC). The level most often asked for in defence engineering. It is for people with long-term, frequent and uncontrolled access to SECRET information, and occasional supervised access to TOP SECRET. Alongside the CTC checks, it includes a credit and financial history check.

Enhanced Security Check (eSC). Used for a limited number of specific roles. It adds financial and internet questionnaires and a detailed interview with a trained Investigating Officer.

Developed Vetting (DV). The highest common level, for people with frequent and uncontrolled access to TOP SECRET information. It includes everything in SC, plus a full financial review, a detailed interview and interviews with referees who know you well.

Enhanced Developed Vetting (eDV). Reserved for a very small number of posts that need assurance beyond DV.

How do you get security clearance?

You cannot apply for security clearance yourself. It has to be sponsored by an employer or government organisation for a specific role. In practice, the process usually looks like this:

1 - You are offered a role that needs clearance. The offer is often conditional on clearance being granted. Depending on the role, you may be able to start on restricted duties while you wait.

2 - Your employer sponsors your application. Their security team starts the process and you are invited to complete an online questionnaire.

3 - The checks are carried out. These depend on the level, and can include identity, employment history, criminal records, credit and financial checks, and Security Service records.

4 - Interviews, for the higher levels. eSC and DV include a detailed interview with an Investigating Officer, and DV also involves interviews with your referees.

5 - A decision is made. Your sponsor is told the outcome and the clearance is recorded against your role.

Residency and nationality

Vetting relies on being able to check your background, so there are normally minimum periods of UK residence, typically around five years for SC and ten years for DV. Time spent abroad does not automatically rule you out, particularly if it was in the armed forces, Crown service or for study, but it can mean extra checks and a longer process.

Nationality requirements are set by the employer and the programme rather than by the clearance level itself. Many UK defence roles, particularly those involving UK Eyes Only information, require current British citizenship. Dual nationals with British citizenship are usually fine, but it is always worth checking for each role.

How long does it take?

Timescales vary with demand and with how straightforward your background is. As a rough guide, SC often takes 4 to 12 weeks and DV can take six months or more. Time spent overseas, gaps in your history or complex finances can all add time, so it pays to plan ahead.

Will something in my past stop me getting clearance?

Not necessarily. Debts, past convictions or time abroad do not automatically rule you out. Vetting looks at the whole picture, including how recent something was and how you have dealt with it. What matters most is honesty. Failing to declare something is usually viewed far more seriously than the issue itself.

How long does clearance last?

Clearances are reviewed at set intervals. Under current government guidance, SC is formally reviewed after 10 years (7 years for some contractors) and DV after 7 years. Organisations can also review clearances earlier.

Because clearance is linked to a sponsor, it does not simply travel with you when you change jobs. A new employer can often transfer an existing clearance rather than starting again, but if you have been out of a cleared role for some time it may have lapsed. When you speak to us, tell us the level you hold, who sponsored it and roughly when it was granted, and we can help you work out where you stand.

Tips if you are applying for cleared roles

Be open and accurate. Complete every question fully and consistently, and declare anything you are unsure about.

Have your history ready. Addresses, employers, dates and referees going back five to ten years make the forms much quicker.

Keep your finances in order. Financial checks form part of SC and above, so it helps to know what is on your credit file.

Tell your recruiter early. We screen clearance and eligibility in our first conversation, so we only put you forward for roles where it fits.

A note for employers

Cleared candidates are in high demand, and waiting for new clearances can add months to a hire. Building vetting timescales into your plans, and considering strong candidates who are eligible for clearance rather than only those who already hold it, can widen your shortlist considerably. We can share a realistic view of the cleared talent market for your role before you commit to a brief.

This guide is general information based on UK government guidance at the time of writing. Requirements differ between roles and organisations, so always check the specific requirements with the employer.