IKEA BILLY bookcase: spare parts, variations and assembly tips

A peg that disappears during a move. A shelf that sags under books. A glass door hinge that breaks. The BILLY has existed since 1979 and remains the best-selling IKEA furniture in the world — its small parts, however, tend to get lost. This page is here to help you find them.

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BILLY variations: which size for which use?

BILLY is not a piece of furniture, it is a system. It comes in three main dimensions, complemented by vertical extensions.

Model	Dimensions (W x D x H)	Typical use
Narrow BILLY	40 x 28 x 202 cm	Hallway, space between two windows
Standard BILLY	80 x 28 x 202 cm	Main bookcase, living room wall
Half-height BILLY	80 x 28 x 106 cm	Under a window, desk, children's bedroom
40 cm extension	40 x 28 x 35 cm	Add a section up to the ceiling
80 cm extension	80 x 28 x 35 cm	Same on standard version

The extensions are placed directly on the main frame to reach a total height of 237 cm. Ideal for making the most of ceiling heights.

Available finishes: white (the historical reference), oak effect, walnut-patterned brown. Since 2022, wood finishes are no longer obtained by veneering but by paper-foil printing — a change visible to the naked eye on the edges and noticeable to the touch.

Glass doors (OXBERG model) fit on the standard 80 cm BILLY. They transform the bookcase into a closed display case: ideal for protecting books from dust or displaying collectibles.

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Parts that disappear (and how to find them)

Shelf peg: the most ordered part

This is the most requested BILLY spare part. A move, a curious child — and half of the pegs evaporate.

What you need to know: the BILLY instructions indicate 10 pegs. In reality, 12 are needed to place all the shelves in their optimal position. This error in the old instructions has generated thousands of replacement orders.

The pegs are small cylindrical pins made of metal (or plastic on models post-2022). They fit into the pre-drilled holes of the side panels and support the shelves from below.

To order your missing pegs: go to the IKEA bookcase spare parts service, enter your BILLY product number, or bring your instructions to the store. Standard screws are provided free of charge up to a limit of 50 pieces.

Assembly screws #104321 and #104323

These two references cover the screws for fixing the back panel and the panels. They keep the structure rigid. If they are lost or the wood around has crumbled, the bookcase loses its lateral stability.

Wooden dowel #101339: used for the dowel joints between the horizontal and vertical panels. Absolutely keep during disassembly-reassembly.

Glass door hinge (OXBERG)

The OXBERG glass door uses a specific hinge, different from IKEA kitchen hinges. It is damaged if the door is pulled sideways or if the side panel has been impacted. The reference is indicated on the OXBERG instructions, not on the BILLY instructions.

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Common problems and solutions

The shelf sags. This is the historical problem of the BILLY. In 1988, IKEA reduced the width of the frame from 90 to 80 cm precisely to limit the deflection under load. The limit not to exceed is 15 kg per shelf. Beyond that, the melamine panel bends irreversibly. Solution: redistribute the loads, or order a replacement shelf.

The side panels split. This happens almost exclusively when the furniture falls over. Melamine cannot be repaired — the panel must be replaced. This is also the reason why wall mounting is not optional.

The back panel comes unstuck. The back is fixed with staples and gluing. If it comes loose, wood glue and a clamp will solve the problem.

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Wall mounting: mandatory, not optional

A 202 cm BILLY not fixed to the wall is a hazard. IKEA provides the fixing kit in the box — a metal bracket and its plasterboard screw. Its use has been imposed by the instructions for several years, notably after accidents involving children.

Operating procedure: the bracket is screwed to the top of the back panel and fixed to the wall with a plug adapted to the support (concrete, plasterboard, brick). On plasterboard, imperatively use an expansion plug or a Molly plug — the standard fixing does not hold.

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BILLY before and after 2022: what has changed

The 2022 redesign has modified two visible technical points:

1. Wood veneer replaced by paper-foil printing. The visual result is acceptable from a distance, but the edges are less resistant to shocks and moisture.
2. Metal fixings replaced by plastic on certain assemblies. Users report a decrease in rigidity over time.

IKEA presents these changes as material optimization. Users who have owned previous models see them as a qualitative regression. Both readings are accurate.

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FAQ

Can you assemble two BILLY bookcases side by side at a right angle? Yes, via a joining bracket. The two frames are fixed to each other by the side panel, forming a 90° angle. The result is stable provided the whole is also fixed to the wall.

How many pegs are needed per BILLY? 12 to use all the positions. The old instructions only indicate 10 — allow a margin.

Does the BILLY extension fit all models? Only to frames of the same width (40 on 40, 80 on 80). It is not compatible with OXBERG glass doors once installed.

Can I get the missing parts for free at IKEA? Yes, for standard screws (screws, dowels, pegs) up to a limit of 50 pieces per order. The request is made online on IKEA.fr, after-sales service / compatible IKEA spare parts section, or directly in store at the customer service desk.