LANCASHIRE LOCKSMITH • HOMES & BUSINESSES
A mortice lock sits inside the thickness of a timber door rather than on its face. Most home insurance policies ask for a five-lever mortice deadlock to BS3621 on final-exit doors. Supply and fitting starts at £156 and normally includes three keys.
From £156 · call-out and labour rates
Timber front and back doors are usually secured by a mortice lock. We supply and fit five-lever sashlocks and deadlocks, including BS3621 insurance-standard options, across Lancashire.
A sashlock has both a latch and a bolt, so it holds the door closed and locks it; it is the usual choice where there is no separate handle set. A deadlock has a bolt only and is fitted alongside a nightlatch on a front door. If you are replacing like for like, the existing lock case tells us which you have; a photograph of the faceplate on the edge of the door is usually enough to identify it.
BS3621 is a British Standard for thief-resistant locks that can be key-locked from both sides. Locks meeting it carry a kitemark on the faceplate. Many insurers specify it for final-exit doors, and some will question a claim if it was not fitted — but policies differ, so read your own wording rather than assuming. We can tell you what is currently on your door and what the standard version would be.
Where the new lock matches the old case size, it goes into the existing mortice and the job is straightforward. A different case depth or backset means enlarging the mortice and adapting the keep in the frame, which takes longer. Old doors are often not square, so the keep position frequently needs adjusting for the bolt to throw fully — a bolt that only part-engages offers very little resistance.
Mortice locks and deadlocks are listed from £156, which covers a standard replacement into an existing mortice. Enlarging a mortice, replacing a damaged keep or working on a door that needs easing first takes longer and is charged accordingly. Call-out and labour are separate and published in full on the pricing page. Three keys are normally supplied with the lock.
Open the door and look at the metal faceplate on its edge. A lock meeting the standard carries a kitemark and the number BS3621 stamped on the faceplate. If there is no marking, it is not a standard lock, whatever the key looks like.
Many policies do for final-exit doors, but not all, and the wording varies between insurers. Check your own policy document rather than relying on general advice. If it specifies BS3621, fitting a lock that meets it is straightforward and inexpensive compared with a disputed claim.
No. Mortice locks are for timber doors. uPVC and composite doors use a multipoint mechanism operated by a euro cylinder, which is a different repair entirely — see our uPVC and multipoint page.
Often yes. Mortice locks can be supplied keyed alike so one key operates front and back, which is convenient but does mean a single lost key affects both doors. We will explain the trade-off before ordering.
We cover Lancashire, including the towns below. Call with your postcode to confirm availability for your address.
See every locksmith service · Prices and charges · Contact us
Call with your postcode and lock problem to confirm availability and charges.
