Number Populate in text boxes

Hi @mattg2, since you tagged scripting, here is a general-purpose script that simply adds sequential numbers to selected text frames (it will ignore other types of items). Note that the layer order of the text frames will dictate the order of the serial numbers. To use it, just select some text frames and run script. It will ask which number to start with.

- Mark

/**
 * Will replace selected text frames' contents
 * with a serial number, entered by user.
 * @discussion https://community.adobe.com/t5/indesign-discussions/number-populate-in-text-boxes/m-p/13549934
 * @author m1b
 */
function main() {

    var startNumber = prompt('Number selected items:\nEnter starting serial number', '1');

    if (
        startNumber == null
        || isNaN(startNumber)
    )
        return;

    replaceItemContentsWithSerialNumber(app.activeDocument.selection, startNumber);


    /**
     * Replace contents of items with a
     * serial number starting at `startNumber`.
     * @param {*} items - array or collection of Page Items
     * @param {*} startNumber 
     */
    function replaceItemContentsWithSerialNumber(items, startNumber) {

        startNumber = Number(startNumber);

        if (isNaN(startNumber))
            startNumber = 1;

        for (var i = 0; i < items.length; i++)
            if (items[i].hasOwnProperty('contents'))
                items[i].contents = String(startNumber++);

    };

}

app.doScript(main, ScriptLanguage.JAVASCRIPT, undefined, UndoModes.ENTIRE_SCRIPT, 'Add serial numbers');

Are you placing the text frames one or more than one per page? What do the numbers mean (that is, are they page numbers, section numbers, item numbers, or something else)?

Same page or separate pages - one box per page ?? 😉

If multiple TextFrames on the same page - @Dave Creamer of IDEAS already gave you the correct answer.

Use a numbered list paragraph style. I would also set style to start in the next text frame.