Harpenden mobile coverage O2 83% indoors here, 100% across St Albans AL3 · Central Bedfordshire
No network wins AL3 on overall coverage: all four are within 2 points, but indoors EE, Three and Vodafone reach 92% of sampled addresses and O2 83%.
AL3: Harpenden, Redbourn, Sandridge, Wheathampstead, Markyate, Slip End, Flamstead, St Michael (Central Bedfordshire, Dacorum, St Albans).
AL3 scores
Ofcom Mobile Coverage data (May 2025), measured across 12 addresses in 6 sampled postcodes: AL3 6JR, AL3 6JY, AL3 6RD, AL3 6RL, AL3 6RR, AL3 7AA. Methodology.
How AL3 compares
small sample 12 addresses in 6 postcodes, under the 30 needed for a firm comparison. The figures are shown, but not compared.
Weakest spot in St Albans: AL2 Shenley, where Vodafone reaches 71% indoors.
Indoor signal around AL3
| District | km away | EE | O2 | Three | Vodafone |
|---|---|---|---|---|---|
| AL3 Harpenden (here) small sample | – | 92% | 83% | 92% | 92% |
| AL5 Harpenden, Wheathampstead | 4 | 97% | 100% | 100% | 100% |
| AL1 Sopwell, Verulam | 5 | 100% | 100% | 100% | 100% |
| AL4 Marshalswick, Kimpton | 6 | 100% | 100% | 100% | 100% |
| AL2 Shenley, St Stephen | 7 | 100% | 100% | 100% | 71% |
| St Albans average | – | 99% | 100% | 98% | 98% |
Small sample: under 30 addresses sampled.
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1pMobile runs on EE's network: £5 a month for 5GB (read 19 October 2026). A price, not a coverage ranking: Ofcom separates no network here.
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