Replace your keys.

Whether you have snapped a key in the barrel or need to "rekey" your entire house for peace of mind, hiring a professional locksmith ensures your home remains secure. This guide breaks down the process, costs, and regulations involved in professional key and lock replacement in the UK.

What Does the Work Involve?

A professional locksmith does more than just replicate keys. The scope of work typically includes several technical steps to ensure the security of your door remains intact.

• Initial Assessment: Identifying the lock type, such as Euro cylinders (common on uPVC doors), Mortice locks (common on timber doors), or Rim cylinders (Yale-style night latches).
• Non-Destructive Entry: If you are locked out, a professional will attempt to gain entry without damaging the door or frame using picking or bypassing techniques.
• Component Replacement: Removing the existing cylinder or internal lock case and installing a new unit with a fresh set of keys.
• Key Cutting and Coding: Providing additional copies of the new key or programming electronic "transponder" keys for high-security systems.
• Security Alignment: Adjusting the strike plates and door furniture to ensure the new lock operates smoothly without sticking or forcing.
• Broken Key Extraction: Using specialist tools to remove snapped fragments from inside a lock barrel before deciding if a replacement is necessary.

Typical Costs

Locksmith pricing in the UK varies based on your location (London and the South East typically command higher rates) and the time of day. Emergency "out-of-hours" calls will almost always incur a premium.

Total project costs are heavily influenced by the "security rating" of the hardware. While a basic cylinder is cheap, many UK insurers now insist on 3-star Kitemarked cylinders or BS3621 compliant locks, which carry a higher price tag but offer superior protection.

How Long Does It Take?

Most key replacement jobs are relatively quick, provided the locksmith has the correct parts on their van. Standard UK lock types are usually stocked as "van stock."

• Standard Cylinder Swap: 20–40 minutes. This is a straightforward "straight swap" of the barrel.
• Mortice Lock Replacement: 45–90 minutes. May require minor carpentry if the new lock body differs slightly in size.
• Emergency Lockout & Replacement: 1–2 hours. Includes the time taken to gain entry and then secure the property.
• Multipoint Linkage Repair: 2–4 hours. If the internal mechanism of a uPVC door has failed, the entire strip may need replacing.

DIY or Professional?

Replacing a basic Euro cylinder is a common DIY task, but it comes with significant risks. If you measure the cylinder incorrectly and it protrudes more than 3mm from the handle, it becomes vulnerable to "lock snapping"—a common burglary technique.

Professional installation is highly recommended for external doors to ensure compliance with home insurance policies. An incorrectly fitted lock can void your theft cover entirely.

For Mortice locks or multipoint mechanisms, professional tools and knowledge are essential. A locksmith will ensure the door is balanced and the "throw" of the bolt is sufficient to meet British Standards. If you are dealing with "restricted" keys (keys that require a security card to duplicate), you will almost certainly need a registered professional.

Choosing the Right Tradesperson

The locksmith industry in the UK is currently unregulated, meaning anyone can trade as a locksmith. This makes it vital to do your due diligence before letting someone into your home.

• Check for Accreditation: Look for members of the Master Locksmiths Association (MLA). They are vetted, inspected, and qualified.
• DBS Checked: Ensure the locksmith has a clean, recent Basic DBS check for your own safety and peace of mind.
• Clear Pricing: Avoid "prices starting from £39" adverts, which often lead to huge hidden costs. Ask for a fixed quote for the call-out and an estimate for parts.
• Local Presence: Use a local firm with a physical address rather than a national call centre, which often adds a significant commission to the bill.

Questions to ask:

• "Are the locks you supply BS3621 compliant or 3-star rated?"
• "Do you offer a guarantee on both the parts and your workmanship?"
• "Will you provide a VAT receipt and a written breakdown of the work performed?"

UK Regulations

While there is no "Locksmith Act," there are several standards that dictate what is acceptable for home security in the UK. Your locksmith should be well-versed in these:

• BS3621: The British Standard for thief-resistant locks. Most insurers require the main entry/exit door to have a lock meeting this standard.
• TS007: The standard for cylinders and security hardware. A "3-star" solution (either a 3-star cylinder or a 1-star cylinder with a 2-star handle) is the current gold standard for uPVC doors.
• Part Q (Building Regulations): Applies to new build homes or extensions, requiring all easily accessible doors and windows to meet specific security performance requirements (often PAS 24).
• Fire Safety: In blocks of flats, your front door must usually be a fire door. Replacing locks on these doors requires specific hardware that does not compromise the door's fire integrity.

Common Problems

Avoid these frequent pitfalls when arranging a key or lock replacement:

• Lock Protrusion: Fitting a cylinder that is too long for the door. This leaves it exposed to snapping and is a major security flaw.
• Poor Key Duplication: Cheap "high street" key cuts often have burrs or slight misalignments that can wear down the internal pins of your new lock prematurely.
• Using the Wrong Lubricant: Never use WD-40 in a lock barrel; it attracts grit and gums up the pins. Always use a dedicated graphite-based lubricant.
• Ignoring the "Lazy" Handle: If your door handle feels floppy, the problem is likely the internal spring or multipoint gearbox, not the key. Replacing the key won't fix the underlying mechanical failure.

Frequently Asked Questions