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Live number

Lasso’s Live Number is your way to find the best available phone number. The numbers are validated in real time through a range of sources, verified for compliance with protection and regulations, and, importantly, prioritized in a way that ensures the best available number at any given moment.

This API requires a livenumber subscription

Contact Lasso at contact@lassox.com or +45 7174 7812 for information

Retrieve company for phonenumber

This endpoint retrieves the CVR registered to a phonenumber through one of our sources. Only accepts integers, e.g. no area codes or similar.

GET api.lassox.com/data/livenumber/lookup/{phonenumber}

GET api.lassox.com/data/livenumber/lookup/71747812

[
    34580820
]

Retrieve live numbers for company

This endpoint retrieves the livenumbers for a specific company.

GET api.lassox.com/data/livenumber/{lassoid}

GET api.lassox.com/data/livenumber/CVR-1-34580820

{
    "lassoId": "CVR-1-34580820",
    "updated": "2026-05-05T11:18:17.267",
    "isRobinson": false,
    "isCommerciallyProtected": false,
    "numbers": [
        {
            "phoneNumber": "71747812",
            "sources": [
                {
                    "type": "CVR",
                    "timestamp": "2026-04-28T08:30:13.8806645",
                    "note": "Registreret i CVR"
                },
                {
                    "type": "Website",
                    "timestamp": "2026-03-30T00:10:16.0761431",
                    "note": null
                }
            ],
            "score": 5.1,
            "explanation": "Dette nummer er fundet i CVR Registeret, vha. internetsøgning og på virksomhedens hjemmeside og er ikke reklamebeskyttet. Du må derfor gerne ringe til det.",
            "callable": true,
            "obfuscated": false
        }
    ]
}

Retrieve live numbers for multiple companies

This endpoint retrieves the livenumbers for a range of companies

POST api.lassox.com/data/livenumber

[
    CVR1, CVR2, CVR3, etc.
]

POST api.lassox.com/data/livenumber

[
    34580820, 12345678
]

[
    {
        "lassoId": "CVR-1-12345678",
        "isRobinson": false,
        "isCommerciallyProtected": false,
        "numbers": [
            {
                "phoneNumber": "87654321",
                "sources": [
                    {
                        "type": "CVR",
                        "timestamp": "2026-04-27T07:34:14.3038662",
                        "note": "Registreret i CVR"
                    }
                ],
                "score": 3.1,
                "explanation": "Dette nummer er fundet i CVR Registeret og vha. internetsøgning og er ikke reklamebeskyttet. Du må derfor gerne ringe til det.",
                "callable": true,
                "obfuscated": false
            }
        ]
    },
    {
        "lassoId": "CVR-1-34580820",
        "isRobinson": false,
        "isCommerciallyProtected": false,
        "numbers": [
            {
                "phoneNumber": "71747812",
                "sources": [
                    {
                        "type": "CVR",
                        "timestamp": "2026-04-28T08:30:13.8806645",
                        "note": "Registreret i CVR"
                    },
                    {
                        "type": "Website",
                        "timestamp": "2026-03-30T00:10:16.0761431",
                        "note": null
                    }
                ],
                "score": 5.1,
                "explanation": "Dette nummer er fundet i CVR Registeret, vha. internetsøgning og på virksomhedens hjemmeside og er ikke reklamebeskyttet. Du må derfor gerne ringe til det.",
                "callable": true,
                "obfuscated": false
            }
        ]
    }
]

Retrieve changes in livenumbers

This endpoint allows you to retrieve any CVR with changes to its livenumbers. Each CVR has an Updated field which is the one we filter and sort by. A change can be anything in the data, so not neccessarily an added or removed number.

If there is more than one page, you can retrieve the next page using the continuationToken found in the previous response, by providing it in the next response with the parameter cToken. If the token is null, there are no more pages. Note that the continuation token is just convenience, and you can do the paging logic yourself using the skip and take parameters.

The following parameters are available:

Name Type Description
since Datetime The minimum value for update time
skip Boolean The amount to skip
take Integer The number of results returned, max 1000
cToken String The continuation token to use 
GET api.lassox.com/data/livenumber?since=DATETIME&skip=INT&take=INT&cToken=STRING

GET api.lassox.com/data/livenumber?since=2026-01-01&skip=0&take=100

{
    "continuationToken": "MjAyMC0wMS0wMVQwMC4wMC4wMHwxMDB8MTAw",
    "results": [
        {
            "lassoId": "CVR-1-34580820",
            "updated": "2026-05-05T11:18:17.267",
            "isRobinson": false,
            "isCommerciallyProtected": false,
            "numbers": [
                {
                    "phoneNumber": "71747812",
                    "sources": [
                        {
                            "type": "CVR",
                            "timestamp": "2026-04-28T08:30:13.8806645",
                            "note": "Registreret i CVR"
                        },
                        {
                            "type": "Website",
                            "timestamp": "2026-03-30T00:10:16.0761431",
                            "note": null
                        }
                    ],
                    "score": 5.1,
                    "explanation": "Dette nummer er fundet i CVR Registeret, vha. internetsøgning og på virksomhedens hjemmeside og er ikke reklamebeskyttet. Du må derfor gerne ringe til det.",
                    "callable": true,
                    "obfuscated": false
                }
            ]
        }
    ]
}