# SY18

Postcode district covering Llanidloes, in Powys.

SY18 is a postcode district covering Llanidloes, in Powys. Median sale price £200,000 in 2025. Recorded crime 50.5 per 1,000 people. About 4,612 people.

Postcode district. Code SY18. In: [Postcodes](https://openindex.co.uk/postcode) › [SY](https://openindex.co.uk/postcode/sy)

Approximate outline worked out by Open Index from the ONS Postcode Directory: each census output area belongs to the district that holds most of its postcodes. People, homes, recorded crime and broadband add up those output areas. House sales count every sale with an SY18 postcode. [How census figures are added up](https://openindex.co.uk/sources/population)

## Key figures

- **Median sale price: £200,000** (2025). The median price paid for a home in SY18 was £200,000 in 2025. Joint 372nd cheapest of 2,235. Source: Worked out by Open Index from HM Land Registry Price Paid Data. Published 28 September 2026. https://openindex.co.uk/postcode/sy18#f-house-sales-median-price
- **Population: 4,529** (2021). SY18 had 4,529 usual residents at the census (ONS Census 2021). 435th least populated of 2,756. Source: Census 2021, England and Wales and Scotland's Census 2022 and Census 2021, Northern Ireland, 2021. Published 21 July 2026. https://openindex.co.uk/postcode/sy18#f-population
- **People in radon Affected Area squares: 100%** (2022). About 100% of people in SY18 live in a 1 km square that the radon atlas marks as a radon Affected Area. UK 44%. Source: Worked out by Open Index from the UKHSA and BGS radon atlas and census output areas. Published 1 December 2022. https://openindex.co.uk/postcode/sy18#f-radon-affected-share
- **Gigabit broadband coverage: 76.7%** (January 2026). In SY18, 76.7% of homes and businesses could get gigabit-capable broadband in January 2026 (Ofcom). UK 87.8%. Source: Connected Nations (Ofcom), January 2026. Published 13 May 2026. https://openindex.co.uk/postcode/sy18#f-gigabit-coverage

## On the map

- [Radon Affected Area by postcode district](https://openindex.co.uk/map/radon-affected-areas?place=SY18) (Worked out by Open Index · 2022): About 100% of people in SY18 live in a 1 km square that the radon atlas marks as a radon Affected Area.
- [Sales per year by postcode district](https://openindex.co.uk/map/house-sales-per-year?place=SY18) (Worked out by Open Index · 2025): 59 homes were sold in SY18 in 2025.
- [Crime and ASB by postcode district](https://openindex.co.uk/map/recorded-crime?place=SY18) (Police recorded crime and outcomes (data.police.uk) · August 2026): Crime and anti-social behaviour for SY18.
- [Population by postcode district](https://openindex.co.uk/map/population?place=SY18) (Census 2021, England and Wales): SY18 had 4,529 usual residents at the census.

## How SY18 compares

Each postcode district against every other postcode district the measure covers.

| Measure | SY18 | Rank | Compared with |
| --- | --- | --- | --- |
| Median sale price | £200,000 | 3rd cheapest | 25 postcode districts, SY · 2025 |
| Population | 4,529 | 6th least populated | 25 postcode districts, SY · 2021 |
| People in radon Affected Area squares | 100% | joint most people in radon Affected Areas | 25 postcode districts, SY · 2022 |
| Gigabit broadband coverage | 76.7% | 8th highest | 25 postcode districts, SY · Jan 2026 |

## Is SY18 safe? What police records show

In the 12 months to August 2026, police recorded crimes and anti-social behaviour in SY18 at a rate of 50.5 per 1,000 people.
That compares with 66.4 per 1,000 people across the SY postcode area.
In August 2026 alone, 16 cases of crime and anti-social behaviour were recorded in SY18.
In the 12 months to August 2026, the most common types were violence and sexual offences (116), anti-social behaviour (40) and other crime (34).
A year earlier, the recorded crime rate in SY18 was 48.1 per 1,000 people.
Worked out by Open Index from police.uk crime records and ONS and NISRA population estimates.
Rates are per resident, so places that many people work in or visit, such as Westminster, the City of London and other city centres, have far higher rates than their residents alone would suggest.

## Deprivation in SY18, neighbourhood by neighbourhood

- Deprivation is ranked by neighbourhood, so SY18 has no single figure. Of its 3 neighbourhoods with a rank:
- Decile 6: 1 neighbourhood
- Decile 8: 2 neighbourhoods

Source: Welsh Index of Multiple Deprivation 2025. Decile 1 is the most deprived tenth of neighbourhoods in Wales.

## Neighbourhoods in SY18

| Area | People (census) | Recorded crime per 1,000 | Deprivation decile | Gigabit broadband |
| --- | --- | --- | --- | --- |
| [Powys 010A](https://openindex.co.uk/powys/neighbourhood/w01000429) | 2,323 | 35.2 per 1,000 | 6 | 45.5% |
| [Powys 010C](https://openindex.co.uk/powys/neighbourhood/w01000466) | 1,335 | 36.9 per 1,000 | 8 | 93.0% |
| [Powys 010D](https://openindex.co.uk/powys/neighbourhood/w01000467) | 1,449 | 80.5 per 1,000 | 8 | 92.4% |

## Your MP

- [Montgomeryshire and Glyndŵr](https://openindex.co.uk/constituency/montgomeryshire-and-glyndwr): Steve Witherden (Labour), MP since July 2024. 98% of the people here.
- [Brecon, Radnor and Cwm Tawe](https://openindex.co.uk/constituency/brecon-radnor-and-cwm-tawe): David Chadwick (Liberal Democrat), MP since July 2024. 1.8% of the people here.

As of 18 October 2026. Contains Parliamentary information licensed under the Open Parliament Licence v3.0. Source: UK Parliament, Members API.

## Middle areas in SY18

[Llanidloes, Blaen Hafren & Llandinam](https://openindex.co.uk/powys/llanidloes-blaen-hafren-and-llandinam)

## Postcode sectors in SY18

[SY18 6 (225 postcodes)](https://openindex.co.uk/postcode/sy18-6)

## Council

[Powys](https://openindex.co.uk/powys)

## Postcode districts next to SY18

[LD1](https://openindex.co.uk/postcode/ld1), [LD6](https://openindex.co.uk/postcode/ld6), [SY16](https://openindex.co.uk/postcode/sy16), [SY17](https://openindex.co.uk/postcode/sy17), [SY19](https://openindex.co.uk/postcode/sy19), [SY23](https://openindex.co.uk/postcode/sy23), [SY25](https://openindex.co.uk/postcode/sy25)

## More in the SY postcode area

[All SY postcode districts](https://openindex.co.uk/postcode/sy), [Every UK postcode area](https://openindex.co.uk/postcode)

## SY18 in brief

SY18 is a postcode district covering Llanidloes, in Powys.
About 4,612 people lived in SY18 in mid-2024 (worked out by Open Index from ONS small-area estimates); the median price paid for a home was £200,000 in 2025 across 59 sales (HM Land Registry) and police recorded crimes and anti-social behaviour at a rate of 50.5 per 1,000 people in the 12 months to August 2026 (police.uk).
The median price paid for a home in SY18 was £200,000 in 2025.
SY18 had 4,529 usual residents at the census.
About 100% of people in SY18 live in a 1 km square that the radon atlas marks as a radon Affected Area.
In SY18, 76.7% of homes and businesses could get gigabit-capable broadband in January 2026.

## About

- Type: Postcode district
- Code: SY18
- Postcode area: [SY](https://openindex.co.uk/postcode/sy)
- Constituency: [Montgomeryshire and Glyndwr †](https://openindex.co.uk/constituency/montgomeryshire-and-glyndwr)
- Council: [Powys †](https://openindex.co.uk/powys)
- Area: 237 km²
- People, mid-2024: 4,612*
- Neighbourhoods: 3
- Output areas: 16

* People: worked out by Open Index from neighbourhood estimates, shared out by where people lived at the census (by area in Northern Ireland). This area's edges do not follow neighbourhood edges, so the figure is close but not exact.
† Best fit: the constituency, council and nation this postcode district mostly lies in. Its edges do not follow theirs.

## Next door

[LD6](https://openindex.co.uk/postcode/ld6), [SY23](https://openindex.co.uk/postcode/sy23), [SY19](https://openindex.co.uk/postcode/sy19), [SY17](https://openindex.co.uk/postcode/sy17), [LD1](https://openindex.co.uk/postcode/ld1), [SY16](https://openindex.co.uk/postcode/sy16)

## Latest updates for SY18

- August 2026 house prices published: HM Land Registry and partners · Oct 2026.
- September 2026 rent published: ONS private rents · Oct 2026.
- Dental practices updated: NHS England · Oct 2026.
- Schools updated: Ofsted · Oct 2026.

The same figures as JSON: https://openindex.co.uk/v1/places/SY18

## How to cite

Source: Open Index, openindex.co.uk. Link to this page, https://openindex.co.uk/postcode/sy18, or to one figure with its anchor, https://openindex.co.uk/postcode/sy18#f-house-sales-median-price.

Open Index's own text and the figures it works out are licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source data keeps its publishers' licences, named with each figure. Give each figure's period and source with it.

Snapshot 2026.10.9. The HTML page: https://openindex.co.uk/postcode/sy18