diff --git a/x-pack/plugins/maps/common/descriptor_types/descriptor_types.d.ts b/x-pack/plugins/maps/common/descriptor_types/descriptor_types.d.ts
index 80e417f9dfa6..4bdafcabaad0 100644
--- a/x-pack/plugins/maps/common/descriptor_types/descriptor_types.d.ts
+++ b/x-pack/plugins/maps/common/descriptor_types/descriptor_types.d.ts
@@ -115,6 +115,7 @@ export type JoinDescriptor = {
 // todo : this union type is incompatible with dynamic extensibility of sources.
 // Reconsider using SourceDescriptor in type signatures for top-level classes
 export type SourceDescriptor =
+  | AbstractSourceDescriptor
   | XYZTMSSourceDescriptor
   | WMSSourceDescriptor
   | KibanaTilemapSourceDescriptor
diff --git a/x-pack/plugins/maps/public/classes/fields/field.ts b/x-pack/plugins/maps/public/classes/fields/field.ts
index 539d0ab4d6ad..04daedc59c03 100644
--- a/x-pack/plugins/maps/public/classes/fields/field.ts
+++ b/x-pack/plugins/maps/public/classes/fields/field.ts
@@ -20,6 +20,7 @@ export interface IField {
   isValid(): boolean;
   getOrdinalFieldMetaRequest(): Promise<unknown>;
   getCategoricalFieldMetaRequest(size: number): Promise<unknown>;
+  supportsFieldMeta(): boolean;
 }
 
 export class AbstractField implements IField {
diff --git a/x-pack/plugins/maps/public/classes/styles/vector/properties/__snapshots__/dynamic_icon_property.test.tsx.snap b/x-pack/plugins/maps/public/classes/styles/vector/properties/__snapshots__/dynamic_icon_property.test.tsx.snap
new file mode 100644
index 000000000000..057907353d68
--- /dev/null
+++ b/x-pack/plugins/maps/public/classes/styles/vector/properties/__snapshots__/dynamic_icon_property.test.tsx.snap
@@ -0,0 +1,78 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Should render categorical legend with breaks 1`] = `
+<div>
+  <EuiSpacer
+    size="s"
+  />
+  <EuiFlexGroup
+    direction="column"
+    gutterSize="none"
+  >
+    <Category
+      color="grey"
+      isLinesOnly={false}
+      isPointsOnly={true}
+      key="US"
+      label="US_format"
+      styleName="icon"
+      symbolId="circle"
+    />
+    <Category
+      color="grey"
+      isLinesOnly={false}
+      isPointsOnly={true}
+      key="CN"
+      label="CN_format"
+      styleName="icon"
+      symbolId="marker"
+    />
+    <Category
+      color="grey"
+      isLinesOnly={false}
+      isPointsOnly={true}
+      key="fallbackCategory"
+      label={
+        <EuiTextColor
+          color="secondary"
+        >
+          Other
+        </EuiTextColor>
+      }
+      styleName="icon"
+      symbolId="square"
+    />
+  </EuiFlexGroup>
+  <EuiFlexGroup
+    gutterSize="xs"
+    justifyContent="spaceAround"
+  >
+    <EuiFlexItem
+      grow={false}
+    >
+      <EuiToolTip
+        content="foobar_label"
+        delay="regular"
+        position="top"
+        title="Icon"
+      >
+        <EuiText
+          className="eui-textTruncate"
+          size="xs"
+          style={
+            Object {
+              "maxWidth": "180px",
+            }
+          }
+        >
+          <small>
+            <strong>
+              foobar_label
+            </strong>
+          </small>
+        </EuiText>
+      </EuiToolTip>
+    </EuiFlexItem>
+  </EuiFlexGroup>
+</div>
+`;
diff --git a/x-pack/plugins/maps/public/classes/styles/vector/properties/__tests__/test_util.ts b/x-pack/plugins/maps/public/classes/styles/vector/properties/__tests__/test_util.ts
new file mode 100644
index 000000000000..1c478bb85ccc
--- /dev/null
+++ b/x-pack/plugins/maps/public/classes/styles/vector/properties/__tests__/test_util.ts
@@ -0,0 +1,75 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+// eslint-disable-next-line max-classes-per-file
+import { FIELD_ORIGIN } from '../../../../../../common/constants';
+import { StyleMeta } from '../../style_meta';
+import {
+  CategoryFieldMeta,
+  GeometryTypes,
+  RangeFieldMeta,
+  StyleMetaDescriptor,
+} from '../../../../../../common/descriptor_types';
+import { AbstractField, IField } from '../../../../fields/field';
+
+class MockField extends AbstractField {
+  async getLabel(): Promise<string> {
+    return this.getName() + '_label';
+  }
+  supportsFieldMeta(): boolean {
+    return true;
+  }
+}
+
+export const mockField: IField = new MockField({
+  fieldName: 'foobar',
+  origin: FIELD_ORIGIN.SOURCE,
+});
+
+class MockStyle {
+  getStyleMeta(): StyleMeta {
+    const geomTypes: GeometryTypes = {
+      isPointsOnly: false,
+      isLinesOnly: false,
+      isPolygonsOnly: false,
+    };
+    const rangeFieldMeta: RangeFieldMeta = { min: 0, max: 100, delta: 100 };
+    const catFieldMeta: CategoryFieldMeta = {
+      categories: [
+        {
+          key: 'US',
+          count: 10,
+        },
+        {
+          key: 'CN',
+          count: 8,
+        },
+      ],
+    };
+
+    const styleMetaDescriptor: StyleMetaDescriptor = {
+      geometryTypes: geomTypes,
+      fieldMeta: {
+        foobar: {
+          range: rangeFieldMeta,
+          categories: catFieldMeta,
+        },
+      },
+    };
+
+    return new StyleMeta(styleMetaDescriptor);
+  }
+}
+
+export class MockLayer {
+  getStyle() {
+    return new MockStyle();
+  }
+
+  getDataRequest() {
+    return null;
+  }
+}
diff --git a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_color_property.test.js b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_color_property.test.js
index b19c25b36984..f4c2b8d92607 100644
--- a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_color_property.test.js
+++ b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_color_property.test.js
@@ -15,65 +15,8 @@ import React from 'react';
 import { shallow } from 'enzyme';
 
 import { DynamicColorProperty } from './dynamic_color_property';
-import { StyleMeta } from '../style_meta';
-import { COLOR_MAP_TYPE, FIELD_ORIGIN, VECTOR_STYLES } from '../../../../../common/constants';
-
-const mockField = {
-  async getLabel() {
-    return 'foobar_label';
-  },
-  getName() {
-    return 'foobar';
-  },
-  getRootName() {
-    return 'foobar';
-  },
-  getOrigin() {
-    return FIELD_ORIGIN.SOURCE;
-  },
-  supportsFieldMeta() {
-    return true;
-  },
-};
-
-class MockStyle {
-  getStyleMeta() {
-    return new StyleMeta({
-      geometryTypes: {
-        isPointsOnly: false,
-        isLinesOnly: false,
-        isPolygonsOnly: false,
-      },
-      fieldMeta: {
-        foobar: {
-          range: { min: 0, max: 100 },
-          categories: {
-            categories: [
-              {
-                key: 'US',
-                count: 10,
-              },
-              {
-                key: 'CN',
-                count: 8,
-              },
-            ],
-          },
-        },
-      },
-    });
-  }
-}
-
-class MockLayer {
-  getStyle() {
-    return new MockStyle();
-  }
-
-  getDataRequest() {
-    return null;
-  }
-}
+import { COLOR_MAP_TYPE, VECTOR_STYLES } from '../../../../../common/constants';
+import { mockField, MockLayer } from './__tests__/test_util';
 
 const makeProperty = (options, field = mockField) => {
   return new DynamicColorProperty(options, VECTOR_STYLES.LINE_COLOR, field, new MockLayer(), () => {
diff --git a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.js b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.js
index 05e2ad06842c..27c4fca7d701 100644
--- a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.js
+++ b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.js
@@ -29,6 +29,11 @@ export class DynamicIconProperty extends DynamicStyleProperty {
     return true;
   }
 
+  getNumberOfCategories() {
+    const palette = getIconPalette(this._options.iconPaletteId);
+    return palette ? palette.length : 0;
+  }
+
   syncIconWithMb(symbolLayerId, mbMap, iconPixelSize) {
     if (this._isIconDynamicConfigComplete()) {
       mbMap.setLayoutProperty(
diff --git a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.test.tsx b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.test.tsx
new file mode 100644
index 000000000000..c27194321302
--- /dev/null
+++ b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_icon_property.test.tsx
@@ -0,0 +1,61 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+// eslint-disable-next-line max-classes-per-file
+import { shallow } from 'enzyme';
+
+jest.mock('ui/new_platform');
+jest.mock('../components/vector_style_editor', () => ({
+  VectorStyleEditor: () => {
+    return <div>mockVectorStyleEditor</div>;
+  },
+}));
+
+import React from 'react';
+import { VECTOR_STYLES } from '../../../../../common/constants';
+// @ts-ignore
+import { DynamicIconProperty } from './dynamic_icon_property';
+import { mockField, MockLayer } from './__tests__/test_util';
+import { IconDynamicOptions } from '../../../../../common/descriptor_types';
+import { IField } from '../../../fields/field';
+
+const makeProperty = (options: Partial<IconDynamicOptions>, field: IField = mockField) => {
+  return new DynamicIconProperty(
+    { ...options, fieldMetaOptions: { isEnabled: false } },
+    VECTOR_STYLES.ICON,
+    field,
+    new MockLayer(),
+    () => {
+      return (x: string) => x + '_format';
+    }
+  );
+};
+
+describe('DynamicIconProperty', () => {
+  it('should derive category number from palettes', async () => {
+    const filled = makeProperty({
+      iconPaletteId: 'filledShapes',
+    });
+    expect(filled.getNumberOfCategories()).toEqual(6);
+    const hollow = makeProperty({
+      iconPaletteId: 'hollowShapes',
+    });
+    expect(hollow.getNumberOfCategories()).toEqual(5);
+  });
+});
+
+test('Should render categorical legend with breaks', async () => {
+  const iconStyle = makeProperty({
+    iconPaletteId: 'filledShapes',
+  });
+
+  const legendRow = iconStyle.renderLegendDetailRow({ isPointsOnly: true, isLinesOnly: false });
+  const component = shallow(legendRow);
+  await new Promise(resolve => process.nextTick(resolve));
+  component.update();
+
+  expect(component).toMatchSnapshot();
+});
diff --git a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_style_property.js b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_style_property.js
index 451a79dd3864..56a461a3bb14 100644
--- a/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_style_property.js
+++ b/x-pack/plugins/maps/public/classes/styles/vector/properties/dynamic_style_property.js
@@ -148,7 +148,8 @@ export class DynamicStyleProperty extends AbstractStyleProperty {
     if (this.isOrdinal()) {
       return this._field.getOrdinalFieldMetaRequest();
     } else if (this.isCategorical()) {
-      return this._field.getCategoricalFieldMetaRequest(this.getNumberOfCategories());
+      const numberOfCategories = this.getNumberOfCategories();
+      return this._field.getCategoricalFieldMetaRequest(numberOfCategories);
     } else {
       return null;
     }