How to overlay INSPIRE polygons on an aerial map

You can do this two ways. Download the INSPIRE Index Polygons and stack them over an aerial layer in QGIS, which is free, capable, and about an afternoon of work the first time. Or open a viewer that has already done the download-convert-tile part and pick a basemap. Both put the same boundaries over the same imagery. The difference is entirely in what you spend to get there.

Which one is right depends on a question worth asking up front: do you want to analyse this data, or do you want to look at it? If you are joining the polygons to your own datasets, running spatial queries, or working offline, QGIS wins and it is not close. If you have one specific question about one specific patch of ground, the setup is the expensive part.

The short answer

INSPIRE Index Polygons are the free, open boundaries of every registered freehold in England and Wales, published by HM Land Registry under the Open Government Licence.
They contain no owner names, no leaseholds, and no legal boundaries. That last one matters and we come back to it.
Any GIS can draw them over aerial imagery or OS mapping. QGIS is the free desktop option.
Whatever you overlay them on, the line you see is indicative.

Route one: build it yourself in QGIS

This is the route most guides send you down, and it genuinely works. Here is the honest version, including the bits that take longer than you expect.

1. Get the polygons

The INSPIRE data lives on the Use land and property data service on gov.uk. No account needed.

It comes split by local authority area, one zip per council. Grab the councils you care about. If you want the whole of England and Wales, you are downloading a few hundred zips.

2. Load them and fix the projection

Inside each zip is a GML file. Geography Markup Language, which is XML with coordinates in it. QGIS will open it.

The geometry arrives in ETRS89 latitude and longitude, because that is what INSPIRE mandates. Your aerial layer is almost certainly Web Mercator, and a lot of British data is British National Grid. QGIS will reproject on the fly, but if your parcels appear somewhere off the west coast of Africa, this is why.

3. Add an aerial layer

QGIS reads XYZ tile services. Add one as an XYZ layer and it sits under your polygons. Read the terms of whichever imagery you use before you rely on it for anything beyond looking, because "visible in a browser" and "licensed for your purpose" are different things.

4. Add OS topographic mapping, if the question needs it

For a stream, a slope, or a footpath, aerial imagery is the wrong layer on its own. You want mapped features.

OS Open Rivers is Ordnance Survey's open watercourse network, free under the OGL from the OS Data Hub, covering freshwater rivers, tidal estuaries and canals across Great Britain. Updated every six months.
Contours and terrain come from OS Terrain 50, also open, with contours at 10 metre intervals.
The Environment Agency publishes river datasets through the Defra Data Services Platform, including the statutory Main River map. That one is England only; for Wales the equivalent comes from Natural Resources Wales. Check the licence on each dataset rather than assuming, because some are conditionally licensed and some carry Ordnance Survey rights on top.

5. Style the polygons so you can see through them

The default fill is opaque, which hides the thing you came to look at. Either drop the fill to a low opacity or switch to outline-only in a bright colour. Then zoom in.

That is it. You now have registered boundaries over a photo, and you can see whether the channel in the imagery crosses the polygon boundary, runs alongside it, or sits inside it.

Where route one bites

None of this is hard. It is just longer than "an afternoon" sounds when you are three hours in.

The download is per-council. Fine for one parish. Tedious for a county, genuinely annoying for a country.

GML is heavy. All those polygons, all that XML overhead. Large files, slow loads, and QGIS will feel it.

Reprojection is a step you will get wrong once. Everyone does.

Rendering a whole county is slow. Desktop GIS draws every feature in view. Past a certain parcel count you are waiting on the map rather than reading it.

It goes stale. HM Land Registry republishes the INSPIRE data monthly, on the first Sunday. Your download does not update itself. Whatever you built in March is a March snapshot.

If you want the full pipeline, including converting GML with ogr2ogr and building vector tiles so it renders at speed, that is written up in what are INSPIRE Index Polygons.

Route two: skip the setup

The alternative is a viewer where the download, conversion, reprojection and tiling have already happened, for the whole of England and Wales, and stay current.

Edgelands is one. It draws the INSPIRE polygons over a choice of basemaps: OS Outdoor, which carries mapped watercourses, contours, paths and field boundaries, and satellite imagery for what is physically there now. There is an opacity slider on the polygon layer, so you can fade the parcels down over the photo rather than styling a layer to see through it, and you can switch basemap without rebuilding anything.

On the satellite view there is also a watercourse layer drawn over the imagery: rivers, streams and canals by default, with drains and ditches available if you want them. That matters more than it sounds. A channel running under tree cover is invisible in an aerial photo, and this is the layer that most guides tell you to go and source yourself.

For a boundary-against-a-feature question, that combination is the whole job. Put the polygons over OS Outdoor to see the mapped stream, flip to satellite to see the actual channel with the watercourse line drawn on top, slide the opacity to compare. Nothing to install, nothing to source, nothing to reproject.

It is £5 a month with a 7-day free trial. QGIS is free forever. That is a real difference and it should be part of your decision.

What neither route can tell you

This is the important section, and it applies identically to both.

The line is not the legal boundary. HM Land Registry works to the general boundaries rule, set out in section 60 of the Land Registration Act 2002. A title plan boundary shows the general extent of the land. It does not determine the exact line. Plans are drawn at 1:1250 in urban areas and 1:2500 in rural ones, where the width of the drawn line itself covers a real distance on the ground.

So "the stream appears to run inside the polygon" is a good answer to "is this worth looking into". It is not evidence in a disagreement with a neighbour. For that you need the deeds, the physical evidence at the date of transfer, and usually a surveyor and a solicitor. There is a formal route, the determined boundary application, and it is covered in the general boundaries rule. If the question is specifically about a watercourse, reading a stream against a UK property boundary covers the riparian ownership rules that sit beneath the visual check.

No owners. INSPIRE has no names in it. The proprietor sits in the title register, which costs £7 from HM Land Registry. See is there a free HM Land Registry map.

Freeholds only. No leaseholds. Flats and leasehold estates are a separate dataset.

A gap is not proof of anything. Missing polygons can mean unregistered land, and HM Land Registry has more than 90% of the land mass of England and Wales on the register, which leaves just under a tenth of the country off it. They can also be digitising artefacts, slivers a metre wide that are noise rather than land. Learn the difference before you get excited.

It stops at the border. England and Wales. Scotland and Northern Ireland have their own registers and their own data.

When QGIS is genuinely the better answer

Not a grudging concession. There are questions where a viewer is the wrong tool and QGIS is obviously right.

You are joining the polygons to your own data. Your survey points, a client's holdings, a spreadsheet of addresses.
You want spatial analysis, not a look. Areas, intersections, buffers, "every parcel within 50 metres of this watercourse".
You need to export. A shapefile, a PDF plan, a layout with a scale bar.
You work offline, or somewhere with no signal.
You want a layer nobody else offers. Soil, flood zones, historic mapping, your own drone imagery.
You have no budget. Free is a legitimate requirement and QGIS meets it completely.

A viewer is for looking. A GIS is for working. Most people asking this question want to look, which is why the shortcut exists, but plenty of people genuinely want to work.

So, which one

If you have one question about one patch of ground and you want the answer this evening, take the shortcut. If you are going to be back next week with a different question and your own data, install QGIS and learn it properly. It is a serious tool and the time pays back.

Either way you are looking at the same open dataset, published free by HM Land Registry, showing the same indicative lines. The only thing that changes is how much of your evening goes on plumbing.

Next: the general boundaries rule for why the line is indicative and what to do when indicative is not enough, how to research a piece of land for the wider desk-research toolkit, or QGIS and Edgelands compared if you are still deciding which tool to use for INSPIRE polygons.

FAQ

Can I overlay INSPIRE polygons on an aerial photo? Yes. The INSPIRE Index Polygons are a free download under the Open Government Licence, and they can be drawn over aerial imagery or OS mapping in any GIS. QGIS is the free desktop route and takes an afternoon to set up. A web viewer that has already processed the data is the no-install route.

Do I need QGIS to view INSPIRE polygons? No. QGIS is the most capable free option and it is the right answer if you want to analyse the data or combine it with your own layers. If you only want to look at boundaries against a photo or a topographic map, a viewer that has already downloaded and tiled the data will get you there faster.

Can I see whether a stream runs through a registered title? You can see whether a watercourse appears to cross a polygon, run alongside it, or sit inside it, which is usually enough to answer the question you actually had. It is not proof. HM Land Registry works to the general boundaries rule, so the line is indicative rather than the precise legal edge.

What basemap should I put INSPIRE polygons on? It depends on the question. Aerial imagery shows you what is physically there now, which is what you want for hedges, tracks and buildings. OS topographic mapping shows mapped watercourses, contours and paths, which is what you want for a stream or a slope. Being able to switch between the two matters more than picking the right one.

Are INSPIRE polygons accurate enough to settle a boundary? No. Under section 60 of the Land Registration Act 2002 the boundary shown on a title plan is a general boundary. It does not determine the exact line. For that you need the deeds, the physical evidence on the ground, and usually a surveyor and a solicitor.