Unlocking Methods & Everyday Convenience

Most modern digital locks give you between four and seven ways in, and you decide which ones to switch on. The common set is fingerprint, a PIN code on a touch keypad, an RFID card or key fob, a smartphone app over Bluetooth, and a mechanical key as a backup.

Mid-range and premium models add more: 3D face recognition, palm or palm-vein reading on newer flagships, remote unlocking over Wi-Fi from anywhere, one-time codes you generate for visitors, and unlocking from a smartwatch or an NFC tag stuck to your phone case. From inside the flat there is usually a thumbturn or a single push-button.

You will not use all of them. In practice most Singapore households settle into two everyday methods plus a backup — typically fingerprint for whoever is home, a PIN for the times your hands are full or wet, and a card kept in a wallet for the helper or an older parent.

The extras matter less than having a sensible fallback when one method fails. A useful rule of thumb when shopping: make sure at least three methods work without your phone and without the internet. If a lock's convenience depends entirely on an app, one flat phone battery turns a good lock into a frustrating one.

For a healthy adult finger enrolled properly, expect the door to open in roughly half a second to a second, and to work first try the large majority of the time. Most current locks use semiconductor or capacitive sensors rather than the older optical type, though optical sensors are still sold and still work, and they read the ridge pattern of live skin, so they are noticeably quicker and more forgiving than the fingerprint readers people remember from a decade ago.

Many also learn — each successful read refines the stored template slightly, so recognition tends to improve over the first few weeks. Real life is messier than a showroom demo.

Wet fingers after washing up, floury or oily hands from cooking, hand cream, plaster over a cut, and very dry skin in an aircon-heavy flat all lower the hit rate. Manual workers and older users with worn ridges see more misses.

On a typical family door, a failed read once or twice a week is normal, not a fault — you simply tap again or use your PIN. The honest expectation to set: fingerprint should feel effortless at least nine times out of ten..

Before buying, try the sensor yourself at a showroom with the hand you actually use, and try it again after washing your hands. That two-minute test tells you more than any spec sheet claim about recognition accuracy.

Most everyday fingerprint misses come down to enrolment, not the lock. The sensor compares what you present against the template captured on day one, so if you enrolled with your finger perfectly centred and pressed flat, every hurried real-world tap at a slight angle looks different.

Rushing enrolment is the single most common cause of a lock that "never recognises me". The fix is to enrol well and enrol generously.

Register the same finger several times using the full number of scans the lock asks for, deliberately shifting position between scans — slightly left, slightly right, higher on the pad, lower towards the tip — so the template covers the way you really touch it. Enrol at least two fingers per person, ideally one from each hand, because you will sometimes approach the door carrying groceries on one side.

Have each family member enrol themselves rather than one person doing everyone's. Day to day, a few habits help:

• Wipe the sensor now and then; dust, rain and sunscreen residue blur the read.
• Dry very wet hands on your shirt before tapping.
• Press and hold briefly rather than stabbing at it.
• Re-enrol a finger if your skin changes — a new job, a healed cut, or persistently dry skin.

If recognition drops suddenly for everyone at once, that is a different problem and worth raising with your installer.

Sometimes, but treat it as a bonus rather than something to count on. Young children's fingerprints are physically small and their ridges are shallow and closely spaced, so many sensors struggle to capture a usable template.

Below roughly primary school age it is hit and miss; from about seven or eight onwards it usually works, though children grow and the template may need re-enrolling every year or so. For the elderly, the issue is worn or flattened ridges, dry skin, and conditions like eczema — the pattern is still there but the contrast the sensor needs is not.

The practical answer for both groups is to give them a different method rather than fighting the sensor. A PIN usually suits most children well, and it is easy to change if it gets shared around the class.

An RFID card or key fob on a lanyard or in a school bag works for younger children and for grandparents who find keypads fiddly, since tapping a card takes no dexterity and no memory. Face recognition can be excellent for an older parent, provided the camera height suits them.

Before you commit, bring the actual person to the showroom and enrol their finger there. Five minutes of testing with the real hand settles the question far better than any assurance, and if it fails you can pick a model whose card or face option they will genuinely find easy.

Yes, it works in the dark — that is one of its main advantages. A 3D face lock does not take an ordinary photograph.

It projects thousands of invisible infrared dots onto your face and reads how that pattern distorts, building a depth map of your nose bridge, eye sockets, cheekbones and jaw. Because infrared light is generated by the lock itself, the system does not depend on room lighting, so it performs the same at a dim HDB corridor at 3am as it does at noon.

Bright direct sunlight is actually the harder case for some models. In use it is the fastest method available: you approach, the lock wakes on a proximity sensor, and the door is usually open in under a second without you touching anything.

That is genuinely useful when you are carrying a baby, a laundry basket or several bags of marketing. The trade-offs are height, distance and power.

The camera reads best when your face is roughly level with it and about an arm's length away, so very tall users, children and wheelchair users may need to adjust, and a few models let you tilt the module. Face locks also draw more battery than fingerprint-only models.

Before buying, stand at the showroom door as you would at home — bag in hand, glasses or mask on — and see whether it reads you naturally at your real height. FYI : 3D Face Recognition is not exactly identical twin proof. Identical twin shares nearly the same facial structure, which could fool the 3D recognition.

A printed photo or a picture on a phone screen will not fool a proper 3D face lock, but the other two cases deserve an honest answer. Because the lock measures depth with infrared rather than matching a flat image, a 2D photo simply has no facial contour for it to read.

Most 3D systems add liveness checks on top — looking for micro-movement, skin response to infrared, blink or subtle warmth — which is why holding up a tablet at the door does nothing. Cheap 2D-camera locks are a different story and are far easier to spoof; they are worth avoiding for a main door.

Identical twins remain the genuine weak point. Facial geometry is close enough that many consumer systems cannot reliably tell twins apart, and manufacturers of phone-grade face recognition have said as much.

A high-quality custom 3D mask built from detailed measurements of a specific person has also defeated some systems in laboratory testing. Neither is a realistic burglary method — both require effort and access no opportunistic intruder has — but neither should be described as impossible.

Keep it in proportion: face recognition is a strong convenience feature with reasonable anti-spoofing, not a guarantee. If you live with an identical twin or sibling who looks very like you, test enrolment carefully at the showroom, and either accept the shared access or use fingerprint as your primary method instead.

A PIN is stored inside the lock itself and checked locally, so it works whether or not there is Wi-Fi, whether or not your phone is with you. Most locks accept codes between four and twelve digits, and you can usually store several separate codes — a master or admin code for yourself, plus user codes for family, a helper or a tenant.

Enter the code on the touch keypad, press the confirm key, and the motor drives the bolt back. Six digits is the sensible sweet spot for a Singapore home: long enough to be hard to guess, short enough that everyone remembers it and children can manage it.

Four digits is workable but thin. Beyond eight, people start writing it down, which defeats the point.

In certain case, the digital lock have a limitation in terms of the digits you set too. Some of them range between 4-12, while there are others which works on 6-12 as well.

What you choose matters more than the length. Avoid your unit number, block number, car plate, phone digits, birthdays and anniversaries — these are the first things anyone who knows you would try.

Avoid sequences and repeated digits like 123456 or 111111. Give the helper, tenant or contractor their own code rather than sharing yours, so you can delete theirs without disrupting the household.

One habit worth adopting: change the master code the day the lock is installed, and again whenever someone with access moves out. Never leave the factory default code in place after handover.

Anti-peep, sometimes called virtual password or random-prefix code, lets you type any number of random digits before and after your real PIN, and the lock still opens as long as your genuine code appears somewhere in the string. If your code is 246810, you can enter 5792468109331 and the door unlocks.

Almost every keypad lock sold today includes this feature; on some it is always active, on others you switch it on in the settings. It matters for two reasons, both about who is watching.

In an HDB corridor, a lift lobby with a clear sightline, or a condo lift landing with a CCTV camera, someone can see your hand from a distance or review footage afterwards. Padding your code with junk digits means a bystander or a recording captures a long string that contains no obvious answer.

The second reason is physical residue — fingerprints, skin oil or heat smudges on a touch keypad reveal which four or six keys you press, narrowing the guesses considerably. Random digits spread the smudges across the whole keypad.

Make it a habit rather than something you remember to do when you feel watched. Start every entry with two or three throwaway digits and finish with two or three more, every single time. It costs you a second and removes the easiest, lowest-effort way for anyone to learn your code.

They are all the same technology in different shapes: a tiny chip and an antenna coil with no battery inside. When you hold the card near the lock's reader, the lock's own radio field powers the chip just long enough for it to transmit its unique ID.

The lock checks that ID against its registered list and opens if it matches. Because there is no battery, a card or fob never needs charging and lasts for years — most cards are worn out by wallets and washing machines rather than by use.

The shapes suit different people. A card is easy to slip into a wallet or lanyard and is the usual choice for helpers, tenants and grandparents.

A fob clips onto a keyring alongside the gate key and letterbox key. A sticker adheres to a phone case or the back of an ez-link card so you tap the thing you are already holding.

Function is identical; pick by habit. Two honest caveats.

Cards can be lost, so register only as many as you actually need and delete a card from the lock immediately if one goes missing. And basic card types can, in principle, be copied by someone with the right reader and physical access to the card — so do not write your block and unit number on it, and do not leave it loose in a car.

Usually yes, though how depends on the model. The most widely supported route is the manufacturer's app over Bluetooth: your phone pairs with the lock, and when you are within a few metres you open the app or a widget and tap unlock.

Some locks add a hands-free option that unlocks as you approach, and many support a smartwatch through a companion app or a shortcut on the watch face, which is handy when you jog or walk the dog without a wallet. NFC is more variable.

On Android, tapping an NFC-enabled phone or an NFC sticker against the reader works on a good number of locks. On iPhone, Apple restricts what third-party locks may do with the NFC chip, so support ranges from limited to unavailable depending on the brand and model year.

Digital key in a phone wallet exists on a small number of premium locks but is not yet common in Singapore. Bear in mind that any phone-based method inherits your phone's problems — flat battery, software update, phone left in the car.

Treat it as a nice extra, not your primary way in. The check to run before buying: check with us exactly which phone and watch you use and would like to pair it to the lock.

While there’s only a handful of product that provide NFC capability, you might also want to try using RFID sticker instead.

Remote unlocking lets you open the door from anywhere with an internet connection, using the manufacturer's app on your phone. It needs the lock to be connected — either through built-in Wi-Fi or through a small bridge or gateway plugged in near the door — and it needs your home Wi-Fi to be working.

Most locks that support it also log every remote unlock, so you can see afterwards exactly when the door was opened. The genuinely useful cases are the ones you cannot plan for.

A child comes home early from school without their card. Your parents arrive to help with the baby while you are stuck at a meeting.

The aircon servicing crew turns up and you are overseas. A relative needs to feed the cat during a long trip.

In each case, the alternative is a wasted trip home or a key hidden somewhere unwise. The caveat is that you are opening your door based on trust, not sight.

Unlocking blind because someone messaged you they are outside is a bad habit — a caller can lie about who is with them. Pair remote unlock with a video doorbell or a digital door viewer so you can confirm who is actually standing there before you tap.

If remote unlocking matters to you, check with AN Digital Lock whether the model needs a separate gateway and whether the app charges any subscription for the feature as different models varies.

A temporary PIN is a code you generate in the app that stops working after a set point — either after a single use, or once a short window expires, say between 2pm and 5pm this Saturday. You send it by WhatsApp, the visitor keys it in, and afterwards it simply no longer opens the door.

You never share your real code and you never have to remember to delete anything. There are two ways locks do this.

Connected models create the code on the server and push it to the lock over Wi-Fi. Offline models use a clever time-based algorithm — the app and the lock share the same secret and clock, so the app can calculate a valid one-time code without the lock ever touching the internet.

The offline approach is very reliable and is why some locks offer this feature with no gateway at all. Typical uses are the part-time cleaner who comes once, a plumber or aircon technician arriving while you are at work, a friend collecting something you left out, or a relative staying for a weekend.

Most locks record which code was used and when, so you know the visit happened. Before you rely on it, generate one and test it on your own door once. Confirm that it really expires afterwards — a code you assume has lapsed but has not is worse than no system at all.

On many connected locks, yes — this is usually called scheduled, recurring or periodic access, and it is different from a one-off visitor code. Instead of a code that dies after one use, you attach a repeating rule to a specific user: this fingerprint, card or PIN works Monday to Friday from 9am to 6pm, and does nothing outside those hours.

The lock enforces the rule itself, so you set it once and forget it. The typical uses in Singapore homes are a part-time helper who comes Tuesday and Friday mornings, a weekly cleaner, a tuition teacher, a caregiver on fixed shifts, or a tenant in a rented room whom you would rather not have roaming the flat at 3am.

It is also useful for older children, where you want to know the door only opens on their credential during school-return hours. Two honest limits.

Not every lock supports it — plenty of good locks offer one-time codes but no recurring schedules — and on the ones that do, the feature often requires the app and sometimes a gateway. Schedules also depend on the lock's internal clock, which can drift or reset after a battery change, so check it after any battery swap.

If timed access is a real requirement for your household, say so explicitly when shopping and ask the retailer to show you the schedule screen in the app before you decide.

Auto-lock makes the door secure itself a few seconds after it closes, without anyone touching it. The lock senses the door has shut and drives the bolt out automatically — typically after a delay you can set from a few seconds up to about a minute, depending on model.

Yes, you should turn it on. It is the single feature that removes the most common household security failure, which is not a break-in but a door left merely pushed to, unlocked, all afternoon.

For families it also ends the "did you lock the door?" argument, and it means teenagers and elderly parents cannot forget. If you have a metal gate with its own lock, the same logic applies there.

The one real drawback is locking yourself out during small trips — taking rubbish to the chute, collecting a delivery downstairs, chatting with a neighbour. This catches people in the first week.

The answer is not to disable auto-lock but to carry a credential you always have on you: your fingerprint if it is reliable, or a card tucked in your phone case. Set the delay to suit your habits — a longer delay if you often prop the door while ferrying shopping in, a short one if the door faces a public corridor. Then run one deliberate test: close the door, wait, and confirm from outside that it has actually thrown the bolt.

Passage mode temporarily disables the locking action so the door opens freely on the handle, like an ordinary unlocked door, until you switch it off. On some locks it is called hold-open or manual lock, do-not-disturb-off, or free-passage.

You activate it from the inside panel or the app, and it stays on until cancelled — unlike auto-lock, which is about the door securing itself, passage mode is about deliberately keeping it open. The situations it earns its keep are the busy ones.

Moving-in day, when the movers are carrying boxes in and out for three hours. Renovation days with contractors coming and going.

A house-warming or a Chinese New Year open house where relatives are in and out all afternoon. Airing the flat with the main door open behind a locked metal gate.

In each case the alternative is a lock that fights you every few minutes or a door propped with a shoe. The obvious caution is remembering to turn it off.

A door left in passage mode overnight is simply an unlocked door, and no amount of good hardware helps. Many locks give you a visual or audible reminder; some auto-cancel at a set time.

Make it a rule: never leave passage mode on when the last person leaves or when everyone goes to bed. If your lock offers an automatic timeout for passage mode, set it — it removes the human error entirely.

Most deliveries in Singapore are left at the door or gate rather than handed over, so the lock's real job is letting you handle the exceptions without being home. For everyday food orders nothing changes — the rider leaves it outside and you collect it.

Where a digital lock helps is bulky items, furniture, appliances and grocery deliveries that need someone to open up. Three approaches cover almost every case.

Give the delivery company a one-time PIN valid for the delivery window, so they can open the metal gate and place the item inside without you sharing anything permanent. Or use remote unlock when they call, ideally after confirming who is there through a video doorbell or digital door viewer.

Or, if you would rather not grant entry at all, simply speak to them through a doorbell camera and direct them to leave it at the gate. Two sensible limits.

Never give a delivery rider your regular household PIN — one-time codes exist precisely for this. And check whether your lock records an access log, so you can see afterwards exactly when the code was used and by whom.

A good habit for larger deliveries: set the one-time code to expire the same day, and pair it with a camera or door viewer. Convenience without a way to verify who walked in is not really convenience.

Almost every digital lock sold for a main door still includes a mechanical key override, and you should keep those keys. The cylinder is usually hidden — behind a small sliding cover on the outer panel, under a cap at the base, or occasionally on the underside — and it lets the door be opened purely mechanically, with no electronics involved.

Locks typically ship with two or three keys, and your metal gate will have its own separate set. Where you keep them is the whole point.

Inside the flat is useless, since the door you cannot open is the one you are locked out of. Under the mat, in the meter box, above the door frame, in the shoe cabinet outside or taped behind the letterbox are all places a stranger checks first.

The sensible options are a wallet or bag you carry daily, a car or office drawer, and one spare with a trusted family member or close neighbour who lives nearby. Also make sure someone other than you knows the keys exist and where the keyhole is.

Plenty of households only discover the override cover on the day they need it, in the dark, with shopping in hand. Practical takeaway: on installation day, ask our installer to show you exactly where the key cylinder is, test both keys once, then label and store one set outside the flat immediately.

Far more than a household will ever use — most locks in this category store fingerprints and cards in the tens to low hundreds, and typically a smaller number of separate PIN codes, though the exact figures vary considerably by brand and model. Entry-level locks sit at the lower end, premium models at the higher end, and face recognition models usually store far fewer faces than fingerprints because the templates are larger.

To put that in perspective, a five-person HDB household enrolling two fingers each uses ten fingerprint slots. Add a helper, a set of grandparents and a couple of cards, and you are still comfortably inside what almost any lock offers.

Capacity only becomes a real consideration for a large multi-generational household, a shared flat with several tenants, or a small office. The number that actually matters is separate PIN slots, because that determines how many people can have their own code rather than sharing yours.

If you plan to give a helper, a tenant and a cleaner each their own code, check that figure specifically. One thing to plan for regardless of capacity: keep a written note of which slot number belongs to which person.

Locks store credentials by slot, not by name, and deleting the right person later is far easier if you did not have to guess. Ask the retailer for the exact capacity figures on the spec sheet.

You do it yourself, either from the keypad using the admin or master menu, or from the app on a connected lock — no technician visit needed. Adding takes a minute: enter the master code, choose add user, then scan the finger, tap the card or key in the new PIN.

Removing is the same path in reverse, selecting delete and choosing the slot to clear. The catch is knowing which slot belongs to whom.

Locks store credentials as numbered slots, not names, so if you enrolled six fingerprints without recording who was who, you may be guessing. If that happens, the clean solution is to clear all users and re-enrol the people who remain — inconvenient once, but certain.

Some locks also let you delete all cards or all fingerprints as a group. When someone moves out, do the whole job rather than half of it: delete their fingerprint, delete their PIN, delete their card slot, collect the physical card and any gate key back, change the master code, and check the app for any lingering shared access.

A code you assume they forgot is not the same as a code that no longer works. Practical habit worth starting on day one: keep a simple note — in your phone or taped inside a cupboard — mapping slot numbers to names, and update it whenever you add someone.

Physically, usually yes; practically, it depends on the new door. A digital lock is not permanently married to one door, but it does need the new door to match on thickness, backset, mortise size and hole positions.

Moving a lock from an HDB fire-rated main door to a condo door, or from a wooden door to a metal gate, often means the cut-outs do not line up and the new door needs fresh drilling — which, on a fire-rated door, is exactly the kind of modification that must be done properly by a supplier who understands the door's certified assembly. Your stored credentials live in the lock's own memory, not in the cloud, so they travel with the hardware.

That is precisely why you should factory reset the lock before it leaves the old flat, clearing every fingerprint, card and PIN. Equally, if you buy a resale flat with an existing digital lock, reset it and re-enrol everyone on day one — you have no idea how many codes and cards the previous owner handed out.

There is also cost. Removal, re-installation and a replacement lock for the old door often add up to a meaningful share of a new lock's price, and an older lock may be near the end of its warranty anyway.