Professional-grade closed-cell foam mounting tape — the same VHB-type used to bond car trim from the factory — is the most secure way to fix a number plate without screws. Done correctly, with a clean surface and a short dwell period, it holds through motorway speeds, rain, frost and car washes. Done badly — on a dirty or oily bumper, with cheap single-use tape — it'll be on the road before the week's out.
Is tape actually legal for number plates in the UK?
Yes. UK law (the Road Vehicles (Display of Registration Marks) Regulations 2001) specifies that plates must be clearly displayed and securely fixed — it says nothing about how they're fixed. Tape is widely used by dealers, body shops and manufacturers as the primary fixing method. The requirement is security, not screws.
That said: if your plate is cracked, faded, or showing the wrong characters, fix that first. Tape won't make a non-compliant plate legal.
What tape actually works on a bumper?
Standard double-sided tape from a pound shop or a hardware DIY roll will fail outdoors. It uses a water-based acrylic adhesive that softens in heat, weakens in the cold, and loses grip when wet. A plate fixed with this can detach at speed — which is a hazard, and potentially leaves you with an obscured-plate offence.
What you need is a closed-cell acrylic foam mounting tape — the type often called VHB (Very High Bond). This is a dense foam carrier with a solvent-based or structural acrylic adhesive on each face. It:
- Flexes slightly with the bumper, so vibration and thermal expansion don't shear the bond
- Resists water, road salt and detergents
- Holds across a wide temperature range, from winter frost to a sun-baked summer bumper
- Can be cut to match the exact fixing points on your plate
This is the specification used in automotive manufacturing for exactly this kind of exterior trim. Our professional mounting tape range is genuine 3M and tesa stock — not generic rebrands — and includes the grades suited to outdoor automotive use.
How to prep the surface (this is the step most people skip)
The tape bond is only as good as the surface underneath it. A bumper that looks clean to the eye can carry a thin film of wax, silicone, road grime or mould-release residue from the factory — any of these will prevent the adhesive making contact with the actual substrate.
1. Remove the old plate and any old tape residue first.
Use a plastic trim tool or a credit card to lift the foam. Any residue left behind should be softened and lifted before you apply fresh tape — don't tape over the top of old adhesive. (For stubborn residue on paint or plastic, our guide on how to remove double-sided tape residue covers the safest methods.)
2. Degrease with IPA.
Isopropyl alcohol (IPA) wipes are the right tool for this — not WD-40, not kitchen spray, not a damp cloth. IPA evaporates without leaving any oily film, which is why it's the standard pre-bond wipe in automotive and industrial applications. Our kits include an IPA wipe for exactly this reason. Wipe the bumper surface where the tape will sit, and do the same on the back of the plate.
3. Use an adhesion promoter if the bumper is unpainted or low-energy plastic.
Unpainted polypropylene bumpers (common on older or budget vehicles) are notoriously low-energy surfaces — adhesives struggle to grip them without help. An adhesion-promoter wipe, applied after the IPA step and allowed to flash off for 60 seconds, dramatically improves bond strength on these surfaces. This is included in our kits and is genuinely worth using if you're not sure what your bumper is made of.
4. Let both surfaces warm up if it's cold.
VHB-type tape needs a minimum surface temperature to bond properly — generally above around 10°C. If the car's been outside overnight in winter, bring it into a garage for 30 minutes, or warm the surface gently with a heat gun on a low setting before applying.
Step-by-step: applying the tape
What you need:
- Closed-cell foam mounting tape (3–5mm thick strip, or pre-cut to size)
- IPA wipe
- Adhesion promoter wipe (if surface is unpainted plastic)
- Scissors or a sharp craft knife
- Clean dry cloth
Step 1. Clean and degrease both surfaces as above. Let the IPA fully evaporate — around 30 seconds.
Step 2. Cut strips of mounting tape to run around the perimeter of the plate, approximately 10–15mm in from each edge. You don't need to fill the entire back face — four strips forming a near-rectangular frame give a secure, even bond and are easier to apply straight.
Step 3. Peel the backing from one face of the tape and apply firmly to the back of the plate. Run your thumb along each strip with firm, even pressure — you're trying to ensure full contact with the plate, not just the high points.
Step 4. Peel the second liner to expose the open adhesive face.
Step 5. Position the plate carefully on the bumper — you won't easily reposition it once it makes contact. Press firmly across the entire plate for at least 30 seconds, applying as much hand pressure as you can. Pay particular attention to the corners.
Step 6. Leave it alone for at least an hour before driving, and ideally 24 hours before washing the car or driving in heavy rain. The adhesive continues to cure and develop its full bond strength over the first day.
What about the plate fixings holes — do you still need them?
Many number plates come with pre-drilled holes for screw fixing. If you're using tape as your primary method, you don't need to use the screw holes — but some people prefer belt-and-braces: tape across the back and a single cap screw through the centre hole. This is a perfectly reasonable approach for a front plate that takes more impact from debris and road wash.
For rear plates on most passenger cars, tape alone — properly applied to a prepared surface — is sufficient.
When tape isn't the right choice
Foam mounting tape is excellent for smooth or lightly textured bumper surfaces in sound condition. It's less suitable when:
- The bumper surface is heavily textured, rough or porous — the tape can only contact the high points, reducing the bonded area significantly
- The bumper has been resprayed with a flexible paint additive that hasn't fully cured
- The vehicle is used in very high-temperature environments (tow vehicles, track days) where the bumper surface gets extremely hot
In these cases, screw fixings with plastic caps (the standard OEM method) are the safer choice.
If you've had previous issues with tape failing on a car, it's worth reading our troubleshooting post on why double-sided tape stops sticking — most failures trace back to surface prep rather than tape quality.
Common questions
Will tape hold a number plate through a car wash?
A properly applied professional foam mounting tape — pressed firmly to a clean, degreased surface with a 24-hour cure time — will hold through both automatic rollers and pressure washers. Cheap single-sided or stationery-grade tape will not: water infiltrates the adhesive layer and the bond softens. Use the correct grade of tape and allow it to cure before washing.
Can you use the same tape on both front and rear plates?
Yes — the same closed-cell foam mounting tape works on both. The front plate arguably sees more abuse from road debris and water ingress, so if anything, surface prep on the front bumper matters more. Make sure both surfaces are degreased before applying.
How do you remove a number plate fixed with tape without breaking it?
Slide dental floss or a length of fishing line behind one corner of the plate and work it gradually along the tape strips in a sawing motion — this cuts through the foam without flexing the plate hard enough to crack it. Any residue left on the bumper can be softened with IPA or a citrus adhesive remover and lifted cleanly without damaging the paint.
Originally published at Spyder Tape
