What is a BLM file?

A BLM file is a plain-text UK property data feed. Estate agents, letting agents, developers, and property websites use it to move listing data between CRMs, agency sites, and portals without retyping every field. The usual download is a .blm file, often inside a ZIP together with photographs.

There is no single ISO or BSI standard called “BLM”. In practice, software talks about BLM Standard as the common delimited-text layout that grew out of the Rightmove Automated Datafeed (ADF) version 3 style feed. Zoopla, OnTheMarket, and many CRMs accept the same idea with small dialect differences (different delimiters or extra columns). This site generates a generic feed for import into tools that accept that layout — it is not an official Rightmove, Zoopla, or OnTheMarket product.

How the file is structured

A valid feed is split into four tagged sections, in this order, each tag on its own line:

#HEADER# — version, delimiters, property count, generated date, branch id.
#DEFINITION# — the column names, in the order the data rows will use.
#DATA# — one row per listing, fields in that same order.
#END# — marks the end of the file, on the line after the last record.

The header names two delimiters. EOF separates fields. EOR ends a record. Historic Rightmove samples often use ^ between fields and ~ at the end of a row. This converter uses a pipe | as EOF and ~ as EOR, which is what many importers (including ListProperty) expect. Those two characters must not appear inside field values.

Typical fields

The definition line lists the columns the importer will map. Order in the file must match the definition. A compact UK listing usually includes:

AGENT_REF — unique reference for the advert (from the source listing where we can read one).
STATUS — this converter always writes 1 (available). We do not mark under offer, sold, or let.
TRANS_TYPE — 1 sale, 2 rent.
PRICE and PRICE_QUALIFIER (numeric codes such as guide price or offers over, when we can detect them).
RENT_FREQUENCY — filled only for lets (1 monthly, 2 weekly); empty on sales.
PROPERTY_TYPE, TENURE, FURNISHED — numeric codes (for example flat = 6, freehold = 1).
BEDROOMS, BATHROOMS.
ADDRESS_1, TOWN, AREA, POSTCODE1 and POSTCODE2 (outward and inward parts, for example SW1A and 1AA).
SUMMARY (up to 200 characters) and DESCRIPTION (up to 2,000 characters).
NEW_HOME — Y or N when we can tell the advert is a new build.
EPC_CURRENT and EPC_POTENTIAL.
AVAILABLE_FROM, BROCHURE_URL, VIRTUAL_TOUR_URL, and MEDIA_FLOOR_PLAN_01 (floor plan URL when the advert has one).
MEDIA_IMAGE_01 onwards — the original photo URLs from the listing. We always output at least three media columns, and up to twelve if the advert has more images.

Portal dialects add many more columns. We include NEW_HOME and MEDIA_FLOOR_PLAN_01 when we can read them. Importers typically map the columns they know and ignore the rest. Always check the destination site’s import rules after you download a file.

What this converter writes

For one listing URL you are allowed to reuse, we build a Version 3 header, a definition line, a single data row, and #END#. The ZIP contains that .blm file plus the photographs we could download (named like AGENTREF_IMG_01.jpg). The media columns in the feed still hold the original image URLs. Conversion runs in memory and is discarded after the download.

#HEADER#
Version : 3
EOF : |
EOR : ~
Property Count : 1
Generated Date : 2026-09-17 12:00:00
Branch ID : BLMCONVERTER
#DEFINITION#
AGENT_REF|STATUS|TRANS_TYPE|PRICE|PRICE_QUALIFIER|RENT_FREQUENCY|PROPERTY_TYPE|TENURE|FURNISHED|BEDROOMS|BATHROOMS|ADDRESS_1|TOWN|AREA|POSTCODE1|POSTCODE2|SUMMARY|DESCRIPTION|NEW_HOME|EPC_CURRENT|EPC_POTENTIAL|AVAILABLE_FROM|BROCHURE_URL|VIRTUAL_TOUR_URL|MEDIA_FLOOR_PLAN_01|MEDIA_IMAGE_01|MEDIA_IMAGE_02|MEDIA_IMAGE_03~
#DATA#
ABC123_1|1|1|350000|3||6|1||2|1|10 High Street|London||SW1A|1AA|Two bedroom flat|Full description text.|N|C|B|||https://example.com/tour||https://cdn.example.com/1.jpg|https://cdn.example.com/2.jpg|https://cdn.example.com/3.jpg~
#END#

Example of the layout we generate. Real files use the listing you converted. Empty fields stay empty. We strip | and ~ from values so they cannot break the row.

ZIP with photos

This converter always gives you a ZIP: one listing, one BLM, and the photos we could fetch (up to 12). Importers such as ListProperty can use the files in the ZIP; a BLM-only import would use the URLs in MEDIA_IMAGE_*.

When to use it

Use the converter only if you own the listing or are authorised to act for the owner. Paste one public listing page from a supported site, check the preview, then download the ZIP. You stay responsible for the destination import and for only converting adverts you may reuse.

Convert a listing URL