---
title: "Mailing Bags 12x16 — £62K/yr Amazon UK Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/uk/business-industry-science/mailing-bags-12x16"
last_updated: "2026-07-31T13:17:16.097Z"
locale: en
meta:
description: "Niche score 39/100 · £62K/yr market · 82K searches/yr · £5.21 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 39/100 · £62K/yr market · 82K searches/yr · £5.21 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Mailing Bags 12x16 — £62K/yr Amazon UK Niche (2026) - Flapen"
---
# **mailing bags 12x16**
**Skip it**
Prices mostly outside the sweet spot ($2.67–$8.18) — this niche doesn't clear our bar today.
Market size 15Growth 28Conversion 97Competition 37Returns 99Price range 0Avg price 14Brand share 28Review moat 27Quality gap 21
**Returns**
**Incredible****0.1%**
return rate — above 5% kills the launch gate
**Conversion**
**Incredible****14.5%**
search→purchase rate — share of searches ending in a sale
**Competition**
**Okay****63%**
top-5 click share — leaders hold, buyers still browse
**Growth**
**Okay****+2.2%**
90-day search growth — must beat 0% to launch
**Brand share**
**Okay****88%**
top-5 brand share — brands hold most of the demand
**Review moat**
**Okay****3,814.73**
avg incumbent reviews — the moat a new listing must climb
**Quality gap**
**Bad****4.7★**
avg incumbent rating — lower means beatable quality
**Market size**
**Bad****£62K**
£62K/yr · 82K searches
**Avg price**
**Bad****£5.21**
avg listing price — sweet spot $15–$100
**Price range**
**Bad****£2.67–£8.18**
cheapest to priciest tracked listing — scored on the share inside $15–$100
According to Flapen's Amazon United Kingdom niche tracking, mailing bags 12x16 is a £62K/yr Amazon United Kingdom market (82K searches/yr). The top 5 brands hold 88% of demand. Demand peaks in Oct–Nov. Verdict: Skip it — 39/100.
Data updated Jul 21, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **mailing bags 12x16 market data**
- **Units sold / yr**
- **10K–13K**
- avg 250–500/product
- **Revenue / yr**
- **£52K–£65K**
- units × avg price
- **Conversion rate**
- **14.5%**
- **Avg BSR**
- **#13**
- **Page quality**
- **0%**
- **Prime**
- **95%**
- **Sponsored**
- **95%**
- **Out of stock**
- **12.4%**
- **Avg brand age**
- **50 months**
- **Avg seller age**
- **177 days**
## **Competition & brand share**
The top 5 products take 63% of clicks — established leaders, but buyers still shop beyond them.
**Brands**
**10 **▼falling
**Sellers**
**16**
**Top-5 brand share**
**88%**
Top 20: 100%
**Top-5 click share**
**63%**
Top 20: 98%
**Open market**
**8%**
- iSOUL52% - Switory12% - delka10% - Double Dragon9% - Straame5% - 1ABOVE3% - Open — no brand owns it (4 brands, 8%)
## **Demand & seasonality**
Weekly Amazon search volume, last 83 weeks — +2.2% search growth over the last 90 days.
2K2KSpike '25Prime Day '25Spike '26 seasonJanFebMarAprMayJunJulAugSepOctNovDecJanFebMarAprMayJun
Peak months: Oct, Nov · busiest ÷ quietest = 2.2×
[**Open Trend **](https://flapen.com/research/uk/business-industry-science/mailing-bags-12x16/trend)
## **Top mailing bags 12x16 search terms**
- **12x16 mailing bags**21K/yr-3.1%12.0% conv. - **mailing bags 12x16**19K/yr+6.2%11.5% conv. - **12 x 16 mailing bags**14K/yr+6.6%12.3% conv. - **postage bags 12 x 16 inch**11K/yr-4.5%12.0% conv. - **parcel bags 12x16**5K/yr+34.5%12.4% conv. - **medium mailing bags 12x16**3K/yr-0.3%16.0% conv. - **mail bags 12 x 16**4K/yr+14.1%10.9% conv. - **parcel bags 12 x 16 inch**6K/yr-30.0%12.2% conv. [**All search terms **](https://flapen.com/research/uk/business-industry-science/mailing-bags-12x16/search-terms)
## **Top mailing bags 12x16 products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%10%£6K20%£12K30%£19K40%£25K101001K10K100K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 22 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Mailing Bags iSOUL 50 Pcs Shipping Poly Postal Self Seal Bags in Size 12 x 16 Inch Size Small Mailing Bags Postage Packaging Bags 305mm to 407mm**iSOUL**£4.83**4.7★8,846 rev](https://www.amazon.co.uk/dp/B0877436CF) [2**Mailing Bags iSOUL 100 Pcs Shipping Poly Postal Self Seal Bags in Size 12 x 16 Inch Size Small Mailing Bags Postage Packaging Bags 305mm to 407mm**iSOUL**£6.22**4.7★8,846 rev](https://www.amazon.co.uk/dp/B093Y3LRW7) [3**Switory Parcel Bags Mailing 12X16 Inch Postal Bags Self Seal Waterproof Shipping Mailers Mailing Bag for Clothes Envelopes Postage Bag for Packaging 50Pcs (Grey)**Switory**£4.93**4.9★149 rev](https://www.amazon.co.uk/dp/B0FCFC82C8) [4**Double Dragon 50-Pack 12x16 Self-Seal Grey Poly Mailer Bags |Self-Seal Shipping Envelopes | Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcels (Also for Storage)**Double Dragon**£5.26**4.2★5,390 rev](https://www.amazon.co.uk/dp/B0DNWKN9NW) [5**delka Mailing Bags Durable Pink Poly Mailer Bags Tear-Resistant Shipping Envelopes for Clothing Documents Strong Self-Seal Adhesive Waterproof & Lightweight (12x16 25PK)**delka**£4.51**4.6★556 rev](https://www.amazon.co.uk/dp/B0DPGLKT3Q)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**iSOUL Poly Mailer Bags 12x16 Self-Seal Shipping Envelopes Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcel Bag Shipping Post Bag Envelopes 50 Pack Pink**iSOUL**£5.13**80 rev3mo ago](https://www.amazon.co.uk/dp/B0GVKG1XH1) [**iSOUL Poly Mailer Bags 12x16 Self-Seal Shipping Envelopes Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcel Bag Shipping Post Bag Envelopes 50 Pack Grey**iSOUL**£4.35**80 rev3mo ago](https://www.amazon.co.uk/dp/B0GVKJ9SRT) [**iSOUL Poly Mailer Bags 12x16 Self-Seal Shipping Envelopes Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcel Bag Shipping Post Bag Envelopes 50 Pack Hot Pink**iSOUL**£5.02**80 rev3mo ago](https://www.amazon.co.uk/dp/B0GVKCJVLK) [**Switory Parcel Bags Mailing 12X16 Inch Postal Bags Self Seal Waterproof Shipping Mailers Mailing Bag for Clothes Envelopes Postage Bag for Packaging 100Pcs (Grey)**Switory**£6.76**149 rev10mo ago](https://www.amazon.co.uk/dp/B0FCFGY79V) [**Switory Parcel Bags Mailing 12X16 Inch Postal Bags Self Seal Waterproof Shipping Mailers Mailing Bag for Clothes Envelopes Postage Bag for Packaging 50Pcs (Grey)**Switory**£4.93**149 rev10mo ago](https://www.amazon.co.uk/dp/B0FCFC82C8)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**iSOUL Poly Mailer Bags 12x16 Self-Seal Shipping Envelopes Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcel Bag Shipping Post Bag Envelopes 50 Pack Hot Pink**iSOUL**£5.02**4.7★**▲ 240%**](https://www.amazon.co.uk/dp/B0GVKCJVLK) [**iSOUL Poly Mailer Bags 12x16 Self-Seal Shipping Envelopes Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcel Bag Shipping Post Bag Envelopes 50 Pack Pink**iSOUL**£5.13**4.7★**▲ 235%**](https://www.amazon.co.uk/dp/B0GVKG1XH1) [**iSOUL Poly Mailer Bags 12x16 Self-Seal Shipping Envelopes Strong Waterproof Tamper-Proof Polythene Packaging for Clothes Bedding & Parcel Bag Shipping Post Bag Envelopes 50 Pack Grey**iSOUL**£4.35**4.7★**▲ 235%**](https://www.amazon.co.uk/dp/B0GVKJ9SRT) [**Switory Parcel Bags Mailing 12X16 Inch Postal Bags Self Seal Waterproof Shipping Mailers Mailing Bag for Clothes Envelopes Postage Bag for Packaging 100Pcs (Grey)**Switory**£6.76**4.9★**▲ 211%**](https://www.amazon.co.uk/dp/B0FCFGY79V) [**Mailing Bags iSOUL 50 Pcs Shipping Poly Postal Self Seal Bags in Size 12 x 16 Inch Size Small Mailing Bags Postage Packaging Bags 305mm to 407mm**iSOUL**£4.83**4.7★**▲ 150%**](https://www.amazon.co.uk/dp/B0877436CF)
**~~View all trending →~~**
## **What buyers say about mailing bags 12x16**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Quality-Overall**26%
*“Excellent quality”*
**Size-Overall**14%
*“Good size bag”*
**Strength**14%
*“The material that they are made of feels strong”*
**Value For Money**13%
*“Good Value”*
**Advertised Vs Actual Product**10%
*“everything is true to the product description”*
**Ease Of Use**4%
*“Easy to Use”*
**Adhesion/Stickiness**3%
*“The adhesive is extremely strong”*
**Thickness**3%
*“With the sealing making things easy thickness perfect for carriage Thank you”*
**Material Quality**2%
*“strong quality material”*
**Color**2%
*“Great colour”*
### **What buyers complain about **
**Quality-Overall**23%
*“the product quality has deteriorated massively in the latest lot Ive ordered”*
**Size-Overall**11%
*“Not fit for size”*
**Thickness**8%
*“not as thick as others”*
**Color**7%
*“Not pink”*
**Smell**5%
*“I mean they really stink really badly”*
**Strength**4%
*“Not strong”*
**Thin**4%
*“Too thin”*
**Adhesion/Stickiness**3%
*“No sticky adhesive”*
**Material Quality**3%
*“Cheaper material”*
**Advertised Vs Actual Product**3%
*“Not exactly what it says on number”*
### **Top return reasons **
**Size-Overall**65%
**Color**9%
**Quality-Overall**9%
**Adhesion/Stickiness**4%
**Thin**2%
**Compatibility-Overall**2%
**Durability**2%
**Smell**2%
**Strength**2%
**Advertised Vs Actual Product**1%
## **Common questions**
- **Is mailing bags 12x16 profitable to sell on Amazon United Kingdom?**
- The niche generates £62K/yr across 22 tracked products. 4 of 5 products launched in the last 360 days are still selling. 90-day search growth is +2.2%. Flapen's verdict: Skip it (39/100).
- **How competitive is the mailing bags 12x16 niche?**
- 10 brands and 16 sellers compete. The top 5 products take 63% of clicks and top 5 brands hold 88% of demand.
- **What do buyers complain about in mailing bags 12x16?**
- Top complaints mined from reviews: Quality-Overall, Size-Overall, Thickness. The return rate is 0.1%.
- **When does demand for mailing bags 12x16 peak?**
- Demand peaks in Oct–Nov; the busiest month runs 2.2× the quietest.
- **What does it cost to enter the mailing bags 12x16 niche?**
- Listings span £2.67–£8.18; the average listing price is £5.21 (sweet spot $15–$100). The average incumbent carries 3,815 reviews — the moat a new listing must climb.
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