Betfair API Release - betDelayModels added to MarketFilter – 12th January 2026

[BetfairDeveloperProgram]

From 12th January 2026, a new betDelayModels field will be added to MarketFilter.

This impacts all API endpoints using the filter parameter i.e. listEvents, listCompetitions, listTimeRanges, listMarketTypes, listCountries, listVenues, listMarketCatalogue.

These endpoints will support betDelayModels filtering for both PASSIVE and DYNAMIC markets.

Example for listMarketCatalogue:

{
"jsonrpc": "2.0",
"method": "SportsAPING/v1.0/listMarketCatalogue",
"params": {
"filter": {
"eventTypeIds": ["1"],
"betDelayModels": ["PASSIVE"]
},
"marketProjection": ["MARKET_DESCRIPTION"],
"maxResults": 10
},
"id": 1
}

Betfair Developer Program

[MichaelL]

Hi Neil,

Thanks for the announcement. These changes are now in place. But the whole thing is imho still a bit inconsistent.

Referring to: https://betfair-developer-docs.atlas...nge+Stream+API

Here, the MarketFilter object still doesn't seem to know anything about betDelayModels. When I tested, what the API actually does, setting the field in MarketFilter didn't raise an error, but also seemd to have no effect, as also markets having no betDelayModels were returned. Usually I'd expect it to have the same effect as for the non-streaming API.

The MarketDescription field in the documentation for the streaming API got the entry "betDelayedModels" (notice the "ed"), while the API actually returns "betDelayModels".

Kind regards,

Michael

[BetfairDeveloperProgram]

Hi Michael,

Sorry about this. We are aware but unfortunately we cannot amend the documentation until next week. In the meantime, correct name is betDelayModels without the "ed".

Response example:

"priceLadderDescription": {
"type": "CLASSIC"
},
"betDelayModels": [
"PASSIVE",
"DYNAMIC"
]
},

Thanks.