To get information about billing plan settings of current user (billing plan name, balance, days left, available services), account and combined settings, use the command core/get_account_data:

svc=core/get_account_data&params={"type":<int>}

Types of response:

• 1 – minimal information, usually required to estimate the state of logged user;
• 2 – detailed information with combined, personal and billing plan settings.

Minimal information:

{
    "plan":<text>,		/* billing plan name */
    "enabled":<int>,		/* state: 0 - blocked, 1 - active */
    "flags":<uint>,		/* billing plan flags */
    "balance":<text>,		/* balance (with currency) */
    "daysCounter":<int>,	/* days counter */
    "services":{		/* services list */
	<text>:{			/* name */
		"type":<int>,		/* type: 1 - on demand; 2 - periodic */
		"usage":<uint>,		/* quantity of active resources of current service */
		"maxUsage":<int>	/* maximal quantity of resources */
	},
	...
    },
    "dealerRights":<int>,	/* allow using dealer rights for current billing plan: 0 - no, 1 - yes */
    "subPlans": [<text>]	/* array of subplans */
}

Detailed information:

{
    "plan":<text>,		/* billing plan name */
    "enabled":<int>,		/* state: 0 - blocked, 1 - active */
    "flags":<uint>,		/* flags - duplicates the same flags from billing plan settings (see the "plan" field below) */
    "balance":<text>,		/* balance (with currency) */
    "daysCounter":<int>,	/* days counter */
    "settings": {
        "balance":<double>,		/* balance */
        "plan": {			/* billing plan settings */
            "flags":<uint>,		/* billing plan flags */
            "blockBalance":<int>,	/* block balance */
            "denyBalance":<int>,	/* deny balance */
            "minDaysCounter":<int>,	/* minimum days counter */
	    "services":{		/* services list */
		<text>:{		/* name */
			"type":<int>,		/* type: 1 - on demand; 2 - periodic */
			"usage":<uint>,		/* count of used items of a type */
			"maxUsage":<int>	/* maximum allowed items of a type */
			"cost":<text>,		/* cost table */
			"interval":<int>	/* reset interval: 0 - none, 1 - hourly, 2 - daily, 3 - weekly, 4 - monthly */
		},
		...
	     }
        },
	"personal":{			/* personal (account) settings */
		...			/* has the same format as billing plan settings */
	},
	"combined":{			/* combined settings (overlapping billing plan and account settings) */
		...			/* has the same format as billing plan settings */
	}
    },
    "dealerRights":<int>,	/* allow using dealer rights for current billing plan: 0 - no, 1 - yes */
    "subPlans":[<text>]		/* array of subplans */
}

You can find available values of billing plan and account flags, as well as list of services in the chapter Detailed information about account.