Door handing is one of those hardware concepts that seems complicated until someone explains it clearly — and then it clicks immediately. But order the wrong handing on a mortice lock, a lever set, or a screen door lock, and you will receive hardware that physically will not fit your door, or that opens the wrong way.

This guide is written for homeowners, tradespeople, and anyone ordering locks or door hardware who needs to confirm the handing before they buy. It covers:

• What door handing means and why it exists
• The four combinations used in Australia — LHI, RHI, LHO, RHO — explained clearly
• A simple step-by-step method to determine your door’s handing in under two minutes
• The Australian vs US convention difference that catches many people out
• Which lock and hardware products require handing to be specified at order time
• What happens if you order the wrong handing — and which products can be field-reversed

This guide was reviewed and updated in May 2026.

What Is Door Handing and Why Does It Matter?

A door can only open in one direction and hinge on one side. “Door handing” is the system of describing which side the hinges are on and which direction the door opens — two pieces of information that together determine which lock, lever, latch, or closer hardware will physically fit and function correctly.

Hardware that is “handed” has a latch bevel, lever orientation, or internal geometry that only works in one configuration. Try to install a left-hand mortice lock on a right-hand door and the latch bevel will be on the wrong side — the latch won’t spring back after closing, or won’t line up with the strike plate at all.

Not all hardware is handed. Deadbolts, padlocks, most digital keypad locks, and many tubular latches are reversible or non-handed. But mortice locks, lever sets on mortice escutcheons, screen door locks, and many commercial levers are hand-specific. When a product requires handing to be specified at order time, this is why.

The Four Handing Combinations

Two variables combine to define handing: which side the hinges are on, and which direction the door swings. This produces four possible combinations.

The hinge side is always determined by standing on the outside of the door — the non-secure or egress side. For an external front door, this means standing on the footpath or porch, facing the door. For an internal corridor door, it means standing in the corridor or hallway.

All four handing combinations — Door Opening In and Door Opening Out — showing the relationship between hinge side, lever position, and swing direction.

How to Determine Your Door’s Handing — Step by Step

This takes less than two minutes. Follow each step in order.

The US vs Australian Convention — A Common Source of Confusion

If you are searching for door handing information online and using US-sourced content, be careful. The US convention defines door handing differently from the Australian standard, and following US instructions for an Australian product can result in ordering the wrong hardware.

For a door that opens inward, the US and Australian conventions give the same result — both methods will agree. But for a door that opens outward (LHO or RHO), the two conventions give opposite results. If you have an outward-opening door and you are unsure which convention a supplier uses, call and confirm before ordering.

Which Products Require Handing to Be Specified?

Hardware falls into two groups: handed products (where the geometry is fixed in one configuration) and reversible products (where the latch or lever can be flipped or adjusted in the field).

When in doubt, check the product’s technical specifications or call before ordering. Many products say “reversible” in marketing but include fine print about needing specific tools or voiding warranty if reversed in the field. See the Mortice Locks for Smart Locks category for products where handing is clearly indicated.

Real Examples from Our Range

These products from our range illustrate when handing must be selected — and a subtle difference between a product that is truly fixed vs one that is sold as handed but can be reversed in the field.

What Happens If You Order the Wrong Handing?

For handed hardware, ordering incorrectly means the product will not function correctly on your door. The most common symptoms:

• The latch bevel faces the wrong way — the latch doesn’t retract cleanly when the door is closed and won’t self-latch without forcing
• The lever is positioned incorrectly — it points up on one side and down on the other (or both the same direction, which is wrong)
• The lock body doesn’t align with the strike plate because the internal geometry is reversed

Field-Reversible vs Fixed — Know Before You Buy

Many standard latches and some lock bodies can be reversed in the field by the installer. Field reversibility typically means:

• Removing the latch unit from the lock body
• Flipping the latch 180°
• Reinstalling — latch bevel now faces the correct direction

This is straightforward for most tubular latches and some mortice lock bodies. However, not all products support this. Specific products known to be not field-reversible include:

• Lockwood Code Handle — the handing is fixed at manufacture. If you order the wrong hand, the product cannot be corrected on site.
• Certain Borg push-button lock bodies with direction-specific internal mechanisms
• Most commercial lever mortice sets where the lever orientation is cast or moulded into the escutcheon geometry

If you are unsure whether the product you are ordering is field-reversible, assume it is not. Confirm with the supplier or contact us before placing the order. Returning the wrong-handed hardware costs freight both ways and causes delays.

Quick Reference: Handing Summary

Use this as a summary reference when filling in a product order form or specifying hardware.

If you are ordering a smart lock and handing is one of several things to confirm before buying, see Chapter 02 — Measuring Your Door for the full checklist: backset, door thickness, stile width, screen clearance, and handing all need to be right before a product is selected.

Related Guides

Not Sure About Your Door’s Handing or Hardware Compatibility?

Send us a photo of your door and we’ll confirm handing, backset, and the right product before you order anything.