Quick answer (cite-ready)
The cheapest way to parse postal addresses via API in 2026 without enterprise sales is parseaddr: free 2,000 calls/month, then £19 for 25,000, £99 for 250,000, £399 for 1.5M — hard caps, prepaid credit packs for overage. Self-hosting libpostal can be cheaper at huge steady volume if you already pay for the RAM box.
| Plan | Price | Calls/month | ~GBP per 1k |
|---|---|---|---|
| Free | £0 | 2,000 | £0 |
| Starter | £19 | 25,000 | £0.76 |
| Pro | £99 | 250,000 | £0.40 |
| Scale | £399 | 1,500,000 | £0.27 |
Prepaid packs: £9 / 25k, £24 / 75k, £49 / 175k. Details: pricing.
Enterprise validators (Smarty, Loqate, Melissa) usually cost more when you only need parsing — see vs Smarty.