A gel nail refill is due as soon as your natural nail has grown out and a visible gap appears at the cuticle. During a refill (also called an infill), you file down the existing overlay, prep the new growth and fill it with fresh gel – so the look and strength are right again. In this guide you'll learn step by step how to refill gel nails, how often you should plan it and which products you need.

When and how often should you refill gel nails?

As a rule of thumb, gel nails are refilled about every 3 to 4 weeks. How fast your nails grow is individual, though. At the latest when you notice these signs, a refill is due:

• A clear strip of natural nail is visible at the cuticle.
• The apex – the strongest point of the overlay – has grown forward. The nail feels top-heavy and breaks more easily.
• First small lifts appear at the edges.
• Colour or design no longer looks neat because of the regrowth.

If you wait too long, the balance of the nail keeps shifting forward. The risk of breakage rises, and moisture can collect under lifted areas. Regular refills are therefore gentler than rescuing an overlay that has grown out a lot.

What you need for a refill

• File: The BNC HLD Half-Moon File Zebra Red Core is our bestseller – double-sided, with different grits for precise shaping and smoothing. More choice in Files & Buffers.
• E-file (optional): The BNC Ceramic Bit Cylinder Medium removes gel and acrylic with high removal power and almost no heat build-up.
• Buffer: With the BNC Buffer White 100/100 you gently roughen the new growth with a very fine grit.
• Cleaner & wipes: BNC Cleaner Clear (bestseller) degreases and removes the sticky layer. Pair it with the lint-free, tear-resistant BNC wipes by LOHMANN & RAUSCHER.
• Primer: The BNC Primer Ultra Bond is our most-ordered bestseller – acid-free, gentler than acid primers and air-dry in about 30 seconds.
• Gel: The BNC Profi-Gel (bestseller) or the BNC Builder Gel Clear Rose (bestseller) – see the table below. All gels in Builder Gels.
• Finish: The BNC High-Gloss Finish Gel without sticky layer (bestseller) for a shiny final coat.
• UV or UV/LED lamp and, to finish, a nail oil from our nail oils.

How to refill gel nails: step by step

1. Prepare: Wash and disinfect hands, gently push back the cuticles.
2. Correct length and shape: Shorten the overlay to the desired length and refine the shape.
3. File down the old overlay: Thin the surface evenly, especially the apex that has grown forward. The transition to the natural nail must blend smoothly – no ridge. File away lifted areas completely: never apply gel over lifting.
4. Roughen the natural nail: Gently mattify the new growth with the buffer. Only remove the shine, don't thin the natural nail.
5. Remove dust and degrease: Put cleaner on a lint-free wipe and wipe the nail thoroughly. After that, don't touch the nail with your fingers.
6. Apply primer: Brush Primer Ultra Bond only onto the exposed natural nail and let it air-dry – according to the description, curing is not necessary.
7. Bonding layer: Work in a thin layer of gel and cure. For clients who often get lifting, you can use the BNC T3 Fiberglass Gel Pink (bestseller) as a bonding gel here – according to its description it is ideal for lifting problems.
8. Fill in and rebuild the apex: Pick up gel, fill in the new growth and place the highest point back in the centre of the nail. Let it thin out towards the cuticle and the sides without touching the skin. Curing: Profi-Gel and Builder Gel each need 120 seconds in a UV or UV/LED lamp.
9. Refine: Remove the sticky layer with cleaner, file surface and shape smooth, remove dust.
10. Seal and care: Apply a thin coat of finish gel and cure (according to the description 240 seconds in a UV lamp or 120–180 seconds in a UV/LED lamp). As no sticky layer forms, no cleaner is needed. Finally, massage nail oil into the cuticles.

Which gel is best for a refill?

For a refill you can work with a one-phase gel or with a builder gel in a three-phase system. Which system suits you best is explained in detail in our article One-phase gel or three-phase system?. Our two bestsellers compared:

Common refill mistakes – and how to avoid them

• Applying gel over lifting: Always file lifted areas away completely, otherwise the refill will lift again quickly. More causes in our article Gel nails and shellac lifting.
• Gel on the cuticle: If the gel touches the cuticle or side walls, it lifts there easily. Leave a hairline gap.
• Layers too thick: Work in thin layers. The Builder Gel develops heat while curing – thin layers are more comfortable for your client.
• Forgetting the apex: If the highest point isn't rebuilt, the nail stays top-heavy and breaks more easily.
• Over-filing the natural nail: Use file and e-file with a light hand and only roughen the natural nail.
• Not degreasing properly: Oil and dust prevent adhesion. Degreasing with cleaner and a lint-free wipe is a must.

More help with lifting, breakage or heat can be found on our overview page Gel problems & solutions.

FAQ: Gel nail refill

How often do gel nails need to be refilled?

Usually every 3 to 4 weeks. If your nails grow fast or lifting appears earlier, a refill can make sense sooner.

Can I refill my gel nails myself?

Yes, with a little practice a refill also works at home. Careful filing, thorough degreasing and thin layers are key. A self-levelling one-phase gel like the BNC Profi-Gel makes getting started easier.

Do I have to file everything off for a refill?

No. You only thin the old overlay and remove lifted areas completely. Well-adhering gel stays on the nail as a base.

Which gel is suitable for refills?

The BNC Builder Gel Clear Rose is designated as a sculpting and refill gel. As a one-phase gel, the BNC Profi-Gel is a good choice, covering base, build and seal.

What happens if I refill gel nails too late?

The apex moves forward, the nail becomes top-heavy and breaks more easily. Lifting also increases. Then more filing is often needed.

How long does a refill take?

That depends on the regrowth, length and design. With a set routine and an e-file, it's much faster in the salon than a complete new set.