diff --git a/client/src/index.css b/client/src/index.css
index 7219984..32759cd 100644
--- a/client/src/index.css
+++ b/client/src/index.css
@@ -9,7 +9,8 @@
   --font-family: "Manrope";
   --color-brand: 24 90 219;
   --color-accent: 0 166 166;
-  --color-surface: 244 247 251;
+  --color-surface-brand: 244 247 251;
+  --color-surface: var(--color-surface-brand);
   --color-page: 248 250 252;
   --color-text: 15 23 42;
   --color-muted: 90 106 133;
diff --git a/client/src/lib/api.ts b/client/src/lib/api.ts
index c07fccc..a8c5c15 100644
--- a/client/src/lib/api.ts
+++ b/client/src/lib/api.ts
@@ -9,6 +9,8 @@ import type {
   LoginResponse,
 } from "@mrp/shared";
 import type {
+  CrmContactEntryDto,
+  CrmContactEntryInput,
   CrmRecordDetailDto,
   CrmRecordInput,
   CrmRecordStatus,
@@ -140,6 +142,16 @@ export const api = {
       token
     );
   },
+  createCustomerContactEntry(token: string, customerId: string, payload: CrmContactEntryInput) {
+    return request<CrmContactEntryDto>(
+      `/api/v1/crm/customers/${customerId}/contact-history`,
+      {
+        method: "POST",
+        body: JSON.stringify(payload),
+      },
+      token
+    );
+  },
   getVendors(token: string, filters?: { q?: string; status?: CrmRecordStatus; state?: string }) {
     return request<CrmRecordSummaryDto[]>(
       `/api/v1/crm/vendors${buildQueryString({
@@ -174,6 +186,16 @@ export const api = {
       token
     );
   },
+  createVendorContactEntry(token: string, vendorId: string, payload: CrmContactEntryInput) {
+    return request<CrmContactEntryDto>(
+      `/api/v1/crm/vendors/${vendorId}/contact-history`,
+      {
+        method: "POST",
+        body: JSON.stringify(payload),
+      },
+      token
+    );
+  },
   getGanttDemo(token: string) {
     return request<{ tasks: GanttTaskDto[]; links: GanttLinkDto[] }>("/api/v1/gantt/demo", undefined, token);
   },
diff --git a/client/src/modules/crm/CrmContactEntryForm.tsx b/client/src/modules/crm/CrmContactEntryForm.tsx
new file mode 100644
index 0000000..82c987f
--- /dev/null
+++ b/client/src/modules/crm/CrmContactEntryForm.tsx
@@ -0,0 +1,72 @@
+import type { CrmContactEntryInput } from "@mrp/shared/dist/crm/types.js";
+
+import { crmContactTypeOptions } from "./config";
+
+interface CrmContactEntryFormProps {
+  form: CrmContactEntryInput;
+  isSaving: boolean;
+  status: string;
+  onChange: <Key extends keyof CrmContactEntryInput>(key: Key, value: CrmContactEntryInput[Key]) => void;
+  onSubmit: (event: React.FormEvent<HTMLFormElement>) => void;
+}
+
+export function CrmContactEntryForm({ form, isSaving, status, onChange, onSubmit }: CrmContactEntryFormProps) {
+  return (
+    <form className="space-y-5" onSubmit={onSubmit}>
+      <div className="grid gap-5 md:grid-cols-[0.9fr_1.1fr]">
+        <label className="block">
+          <span className="mb-2 block text-sm font-semibold text-text">Interaction type</span>
+          <select
+            value={form.type}
+            onChange={(event) => onChange("type", event.target.value as CrmContactEntryInput["type"])}
+            className="w-full rounded-2xl border border-line/70 bg-page px-4 py-3 text-text outline-none transition focus:border-brand"
+          >
+            {crmContactTypeOptions.map((option) => (
+              <option key={option.value} value={option.value}>
+                {option.label}
+              </option>
+            ))}
+          </select>
+        </label>
+        <label className="block">
+          <span className="mb-2 block text-sm font-semibold text-text">Contact timestamp</span>
+          <input
+            type="datetime-local"
+            value={form.contactAt.slice(0, 16)}
+            onChange={(event) => onChange("contactAt", new Date(event.target.value).toISOString())}
+            className="w-full rounded-2xl border border-line/70 bg-page px-4 py-3 text-text outline-none transition focus:border-brand"
+          />
+        </label>
+      </div>
+      <label className="block">
+        <span className="mb-2 block text-sm font-semibold text-text">Summary</span>
+        <input
+          value={form.summary}
+          onChange={(event) => onChange("summary", event.target.value)}
+          className="w-full rounded-2xl border border-line/70 bg-page px-4 py-3 text-text outline-none transition focus:border-brand"
+          placeholder="Short headline for the interaction"
+        />
+      </label>
+      <label className="block">
+        <span className="mb-2 block text-sm font-semibold text-text">Details</span>
+        <textarea
+          value={form.body}
+          onChange={(event) => onChange("body", event.target.value)}
+          rows={5}
+          className="w-full rounded-2xl border border-line/70 bg-page px-4 py-3 text-text outline-none transition focus:border-brand"
+          placeholder="Capture what happened, follow-ups, and commitments."
+        />
+      </label>
+      <div className="flex items-center justify-between rounded-2xl border border-line/70 bg-page/70 px-4 py-4">
+        <span className="text-sm text-muted">{status}</span>
+        <button
+          type="submit"
+          disabled={isSaving}
+          className="rounded-2xl bg-brand px-5 py-3 text-sm font-semibold text-white disabled:cursor-not-allowed disabled:opacity-60"
+        >
+          {isSaving ? "Saving..." : "Add entry"}
+        </button>
+      </div>
+    </form>
+  );
+}
diff --git a/client/src/modules/crm/CrmContactTypeBadge.tsx b/client/src/modules/crm/CrmContactTypeBadge.tsx
new file mode 100644
index 0000000..0fafa1b
--- /dev/null
+++ b/client/src/modules/crm/CrmContactTypeBadge.tsx
@@ -0,0 +1,13 @@
+import type { CrmContactEntryType } from "@mrp/shared/dist/crm/types.js";
+
+import { crmContactTypeOptions, crmContactTypePalette } from "./config";
+
+export function CrmContactTypeBadge({ type }: { type: CrmContactEntryType }) {
+  const label = crmContactTypeOptions.find((option) => option.value === type)?.label ?? type;
+
+  return (
+    <span className={`inline-flex rounded-full px-3 py-1 text-xs font-semibold uppercase tracking-[0.16em] ${crmContactTypePalette[type]}`}>
+      {label}
+    </span>
+  );
+}
diff --git a/client/src/modules/crm/CrmDetailPage.tsx b/client/src/modules/crm/CrmDetailPage.tsx
index 75155f1..9fa7b74 100644
--- a/client/src/modules/crm/CrmDetailPage.tsx
+++ b/client/src/modules/crm/CrmDetailPage.tsx
@@ -1,12 +1,14 @@
 import { permissions } from "@mrp/shared";
-import type { CrmRecordDetailDto } from "@mrp/shared/dist/crm/types.js";
+import type { CrmContactEntryInput, CrmRecordDetailDto } from "@mrp/shared/dist/crm/types.js";
 import { useEffect, useState } from "react";
 import { Link, useParams } from "react-router-dom";
 
 import { useAuth } from "../../auth/AuthProvider";
 import { api, ApiError } from "../../lib/api";
+import { CrmContactEntryForm } from "./CrmContactEntryForm";
+import { CrmContactTypeBadge } from "./CrmContactTypeBadge";
 import { CrmStatusBadge } from "./CrmStatusBadge";
-import { type CrmEntity, crmConfigs } from "./config";
+import { type CrmEntity, crmConfigs, emptyCrmContactEntryInput } from "./config";
 
 interface CrmDetailPageProps {
   entity: CrmEntity;
@@ -19,6 +21,9 @@ export function CrmDetailPage({ entity }: CrmDetailPageProps) {
   const config = crmConfigs[entity];
   const [record, setRecord] = useState<CrmRecordDetailDto | null>(null);
   const [status, setStatus] = useState(`Loading ${config.singularLabel.toLowerCase()}...`);
+  const [contactEntryForm, setContactEntryForm] = useState<CrmContactEntryInput>(emptyCrmContactEntryInput);
+  const [contactEntryStatus, setContactEntryStatus] = useState("Add a timeline entry for this account.");
+  const [isSavingContactEntry, setIsSavingContactEntry] = useState(false);
 
   const canManage = user?.permissions.includes(permissions.crmWrite) ?? false;
 
@@ -33,6 +38,7 @@ export function CrmDetailPage({ entity }: CrmDetailPageProps) {
       .then((nextRecord) => {
         setRecord(nextRecord);
         setStatus(`${config.singularLabel} record loaded.`);
+        setContactEntryStatus("Add a timeline entry for this account.");
       })
       .catch((error: unknown) => {
         const message = error instanceof ApiError ? error.message : `Unable to load ${config.singularLabel.toLowerCase()}.`;
@@ -44,6 +50,48 @@ export function CrmDetailPage({ entity }: CrmDetailPageProps) {
     return <div className="rounded-[28px] border border-line/70 bg-surface/90 p-8 text-sm text-muted shadow-panel">{status}</div>;
   }
 
+  function updateContactEntryField<Key extends keyof CrmContactEntryInput>(key: Key, value: CrmContactEntryInput[Key]) {
+    setContactEntryForm((current) => ({ ...current, [key]: value }));
+  }
+
+  async function handleContactEntrySubmit(event: React.FormEvent<HTMLFormElement>) {
+    event.preventDefault();
+    if (!token || !recordId) {
+      return;
+    }
+
+    setIsSavingContactEntry(true);
+    setContactEntryStatus("Saving timeline entry...");
+
+    try {
+      const nextEntry =
+        entity === "customer"
+          ? await api.createCustomerContactEntry(token, recordId, contactEntryForm)
+          : await api.createVendorContactEntry(token, recordId, contactEntryForm);
+
+      setRecord((current) =>
+        current
+          ? {
+              ...current,
+              contactHistory: [nextEntry, ...current.contactHistory].sort(
+                (left, right) => new Date(right.contactAt).getTime() - new Date(left.contactAt).getTime()
+              ),
+            }
+          : current
+      );
+      setContactEntryForm({
+        ...emptyCrmContactEntryInput,
+        contactAt: new Date().toISOString(),
+      });
+      setContactEntryStatus("Timeline entry added.");
+    } catch (error: unknown) {
+      const message = error instanceof ApiError ? error.message : "Unable to save timeline entry.";
+      setContactEntryStatus(message);
+    } finally {
+      setIsSavingContactEntry(false);
+    }
+  }
+
   return (
     <section className="space-y-6">
       <div className="rounded-[28px] border border-line/70 bg-surface/90 p-8 shadow-panel">
@@ -76,7 +124,7 @@ export function CrmDetailPage({ entity }: CrmDetailPageProps) {
           </div>
         </div>
       </div>
-      <div className="grid gap-6 xl:grid-cols-[1.2fr_0.8fr]">
+      <div className="grid gap-6 xl:grid-cols-[1.15fr_0.85fr]">
         <article className="rounded-[28px] border border-line/70 bg-surface/90 p-8 shadow-panel">
           <p className="text-xs font-semibold uppercase tracking-[0.24em] text-muted">Contact</p>
           <dl className="mt-6 grid gap-5 md:grid-cols-2">
@@ -99,7 +147,7 @@ export function CrmDetailPage({ entity }: CrmDetailPageProps) {
           </dl>
         </article>
         <article className="rounded-[28px] border border-line/70 bg-surface/90 p-8 shadow-panel">
-          <p className="text-xs font-semibold uppercase tracking-[0.24em] text-muted">Notes</p>
+          <p className="text-xs font-semibold uppercase tracking-[0.24em] text-muted">Internal Notes</p>
           <p className="mt-4 whitespace-pre-line text-sm leading-7 text-text">
             {record.notes || "No internal notes recorded for this account yet."}
           </p>
@@ -108,6 +156,55 @@ export function CrmDetailPage({ entity }: CrmDetailPageProps) {
           </div>
         </article>
       </div>
+      <section className="grid gap-6 xl:grid-cols-[0.85fr_1.15fr]">
+        {canManage ? (
+          <article className="rounded-[28px] border border-line/70 bg-surface/90 p-8 shadow-panel">
+            <p className="text-xs font-semibold uppercase tracking-[0.24em] text-muted">Contact History</p>
+            <h4 className="mt-3 text-xl font-bold text-text">Add timeline entry</h4>
+            <p className="mt-2 text-sm text-muted">
+              Record calls, emails, meetings, and follow-up notes directly against this account.
+            </p>
+            <div className="mt-6">
+              <CrmContactEntryForm
+                form={contactEntryForm}
+                isSaving={isSavingContactEntry}
+                status={contactEntryStatus}
+                onChange={updateContactEntryField}
+                onSubmit={handleContactEntrySubmit}
+              />
+            </div>
+          </article>
+        ) : null}
+        <article className="rounded-[28px] border border-line/70 bg-surface/90 p-8 shadow-panel">
+          <p className="text-xs font-semibold uppercase tracking-[0.24em] text-muted">Timeline</p>
+          <h4 className="mt-3 text-xl font-bold text-text">Recent interactions</h4>
+          {record.contactHistory.length === 0 ? (
+            <div className="mt-6 rounded-3xl border border-dashed border-line/70 bg-page/60 px-6 py-12 text-center text-sm text-muted">
+              No contact history has been recorded for this account yet.
+            </div>
+          ) : (
+            <div className="mt-6 space-y-4">
+              {record.contactHistory.map((entry) => (
+                <article key={entry.id} className="rounded-3xl border border-line/70 bg-page/60 p-5">
+                  <div className="flex flex-col gap-3 lg:flex-row lg:items-start lg:justify-between">
+                    <div>
+                      <div className="flex flex-wrap items-center gap-3">
+                        <CrmContactTypeBadge type={entry.type} />
+                        <h5 className="text-base font-semibold text-text">{entry.summary}</h5>
+                      </div>
+                      <p className="mt-3 whitespace-pre-line text-sm leading-7 text-text">{entry.body}</p>
+                    </div>
+                    <div className="text-sm text-muted lg:text-right">
+                      <div>{new Date(entry.contactAt).toLocaleString()}</div>
+                      <div className="mt-1">{entry.createdBy.name}</div>
+                    </div>
+                  </div>
+                </article>
+              ))}
+            </div>
+          )}
+        </article>
+      </section>
     </section>
   );
 }
diff --git a/client/src/modules/crm/config.ts b/client/src/modules/crm/config.ts
index eaf4a38..6751146 100644
--- a/client/src/modules/crm/config.ts
+++ b/client/src/modules/crm/config.ts
@@ -1,4 +1,11 @@
-import { crmRecordStatuses, type CrmRecordInput, type CrmRecordStatus } from "@mrp/shared/dist/crm/types.js";
+import {
+  crmContactEntryTypes,
+  crmRecordStatuses,
+  type CrmContactEntryInput,
+  type CrmContactEntryType,
+  type CrmRecordInput,
+  type CrmRecordStatus,
+} from "@mrp/shared/dist/crm/types.js";
 
 export type CrmEntity = "customer" | "vendor";
 
@@ -60,4 +67,25 @@ export const crmStatusPalette: Record<CrmRecordStatus, string> = {
   INACTIVE: "border border-slate-400/30 bg-slate-500/12 text-slate-700 dark:text-slate-300",
 };
 
-export { crmRecordStatuses };
+export const emptyCrmContactEntryInput: CrmContactEntryInput = {
+  type: "NOTE",
+  summary: "",
+  body: "",
+  contactAt: new Date().toISOString(),
+};
+
+export const crmContactTypeOptions: Array<{ value: CrmContactEntryType; label: string }> = [
+  { value: "NOTE", label: "Note" },
+  { value: "CALL", label: "Call" },
+  { value: "EMAIL", label: "Email" },
+  { value: "MEETING", label: "Meeting" },
+];
+
+export const crmContactTypePalette: Record<CrmContactEntryType, string> = {
+  NOTE: "border border-slate-400/30 bg-slate-500/12 text-slate-700 dark:text-slate-300",
+  CALL: "border border-sky-400/30 bg-sky-500/12 text-sky-700 dark:text-sky-300",
+  EMAIL: "border border-violet-400/30 bg-violet-500/12 text-violet-700 dark:text-violet-300",
+  MEETING: "border border-rose-400/30 bg-rose-500/12 text-rose-700 dark:text-rose-300",
+};
+
+export { crmContactEntryTypes, crmRecordStatuses };
diff --git a/client/src/theme/ThemeProvider.tsx b/client/src/theme/ThemeProvider.tsx
index 661a6bf..be1bfa7 100644
--- a/client/src/theme/ThemeProvider.tsx
+++ b/client/src/theme/ThemeProvider.tsx
@@ -33,7 +33,7 @@ export function ThemeProvider({ children }: { children: React.ReactNode }) {
 
     document.documentElement.style.setProperty("--color-brand", hexToRgbTriplet(profile.theme.primaryColor));
     document.documentElement.style.setProperty("--color-accent", hexToRgbTriplet(profile.theme.accentColor));
-    document.documentElement.style.setProperty("--color-surface", hexToRgbTriplet(profile.theme.surfaceColor));
+    document.documentElement.style.setProperty("--color-surface-brand", hexToRgbTriplet(profile.theme.surfaceColor));
     document.documentElement.style.setProperty("--font-family", profile.theme.fontFamily);
   };
 
diff --git a/server/prisma/migrations/20260314203000_crm_contact_history/migration.sql b/server/prisma/migrations/20260314203000_crm_contact_history/migration.sql
new file mode 100644
index 0000000..0d6ef7b
--- /dev/null
+++ b/server/prisma/migrations/20260314203000_crm_contact_history/migration.sql
@@ -0,0 +1,19 @@
+CREATE TABLE "CrmContactEntry" (
+    "id" TEXT NOT NULL PRIMARY KEY,
+    "type" TEXT NOT NULL DEFAULT 'NOTE',
+    "summary" TEXT NOT NULL,
+    "body" TEXT NOT NULL,
+    "contactAt" DATETIME NOT NULL,
+    "customerId" TEXT,
+    "vendorId" TEXT,
+    "createdById" TEXT,
+    "createdAt" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updatedAt" DATETIME NOT NULL,
+    CONSTRAINT "CrmContactEntry_customerId_fkey" FOREIGN KEY ("customerId") REFERENCES "Customer" ("id") ON DELETE CASCADE ON UPDATE CASCADE,
+    CONSTRAINT "CrmContactEntry_vendorId_fkey" FOREIGN KEY ("vendorId") REFERENCES "Vendor" ("id") ON DELETE CASCADE ON UPDATE CASCADE,
+    CONSTRAINT "CrmContactEntry_createdById_fkey" FOREIGN KEY ("createdById") REFERENCES "User" ("id") ON DELETE SET NULL ON UPDATE CASCADE
+);
+
+CREATE INDEX "CrmContactEntry_customerId_contactAt_idx" ON "CrmContactEntry"("customerId", "contactAt");
+
+CREATE INDEX "CrmContactEntry_vendorId_contactAt_idx" ON "CrmContactEntry"("vendorId", "contactAt");
diff --git a/server/prisma/schema.prisma b/server/prisma/schema.prisma
index 372ef81..c8f7e61 100644
--- a/server/prisma/schema.prisma
+++ b/server/prisma/schema.prisma
@@ -18,6 +18,7 @@ model User {
   createdAt    DateTime    @default(now())
   updatedAt    DateTime    @updatedAt
   userRoles    UserRole[]
+  contactEntries CrmContactEntry[]
 }
 
 model Role {
@@ -115,6 +116,7 @@ model Customer {
   notes        String
   createdAt    DateTime @default(now())
   updatedAt    DateTime @updatedAt
+  contactEntries CrmContactEntry[]
 }
 
 model Vendor {
@@ -132,4 +134,21 @@ model Vendor {
   notes        String
   createdAt    DateTime @default(now())
   updatedAt    DateTime @updatedAt
+  contactEntries CrmContactEntry[]
+}
+
+model CrmContactEntry {
+  id          String   @id @default(cuid())
+  type        String   @default("NOTE")
+  summary     String
+  body        String
+  contactAt   DateTime
+  customerId  String?
+  vendorId    String?
+  createdById String?
+  createdAt   DateTime @default(now())
+  updatedAt   DateTime @updatedAt
+  customer    Customer? @relation(fields: [customerId], references: [id], onDelete: Cascade)
+  vendor      Vendor?   @relation(fields: [vendorId], references: [id], onDelete: Cascade)
+  createdBy   User?     @relation(fields: [createdById], references: [id], onDelete: SetNull)
 }
diff --git a/server/src/modules/crm/router.ts b/server/src/modules/crm/router.ts
index c85a4be..d4ff40e 100644
--- a/server/src/modules/crm/router.ts
+++ b/server/src/modules/crm/router.ts
@@ -1,11 +1,14 @@
-import { crmRecordStatuses, permissions } from "@mrp/shared";
+import { permissions } from "@mrp/shared";
+import { crmContactEntryTypes, crmRecordStatuses } from "@mrp/shared/dist/crm/types.js";
 import { Router } from "express";
 import { z } from "zod";
 
 import { fail, ok } from "../../lib/http.js";
 import { requirePermissions } from "../../lib/rbac.js";
 import {
+  createCustomerContactEntry,
   createCustomer,
+  createVendorContactEntry,
   createVendor,
   getCustomerById,
   getVendorById,
@@ -35,6 +38,13 @@ const crmListQuerySchema = z.object({
   status: z.enum(crmRecordStatuses).optional(),
 });
 
+const crmContactEntrySchema = z.object({
+  type: z.enum(crmContactEntryTypes),
+  summary: z.string().trim().min(1).max(160),
+  body: z.string().trim().min(1).max(4000),
+  contactAt: z.string().datetime(),
+});
+
 function getRouteParam(value: string | string[] | undefined) {
   return typeof value === "string" ? value : null;
 }
@@ -99,6 +109,25 @@ crmRouter.put("/customers/:customerId", requirePermissions([permissions.crmWrite
   return ok(response, customer);
 });
 
+crmRouter.post("/customers/:customerId/contact-history", requirePermissions([permissions.crmWrite]), async (request, response) => {
+  const customerId = getRouteParam(request.params.customerId);
+  if (!customerId) {
+    return fail(response, 400, "INVALID_INPUT", "Customer id is invalid.");
+  }
+
+  const parsed = crmContactEntrySchema.safeParse(request.body);
+  if (!parsed.success) {
+    return fail(response, 400, "INVALID_INPUT", "Contact history entry is invalid.");
+  }
+
+  const entry = await createCustomerContactEntry(customerId, parsed.data, request.authUser?.id);
+  if (!entry) {
+    return fail(response, 404, "CRM_CUSTOMER_NOT_FOUND", "Customer record was not found.");
+  }
+
+  return ok(response, entry, 201);
+});
+
 crmRouter.get("/vendors", requirePermissions([permissions.crmRead]), async (_request, response) => {
   const parsed = crmListQuerySchema.safeParse(_request.query);
   if (!parsed.success) {
@@ -156,3 +185,22 @@ crmRouter.put("/vendors/:vendorId", requirePermissions([permissions.crmWrite]),
 
   return ok(response, vendor);
 });
+
+crmRouter.post("/vendors/:vendorId/contact-history", requirePermissions([permissions.crmWrite]), async (request, response) => {
+  const vendorId = getRouteParam(request.params.vendorId);
+  if (!vendorId) {
+    return fail(response, 400, "INVALID_INPUT", "Vendor id is invalid.");
+  }
+
+  const parsed = crmContactEntrySchema.safeParse(request.body);
+  if (!parsed.success) {
+    return fail(response, 400, "INVALID_INPUT", "Contact history entry is invalid.");
+  }
+
+  const entry = await createVendorContactEntry(vendorId, parsed.data, request.authUser?.id);
+  if (!entry) {
+    return fail(response, 404, "CRM_VENDOR_NOT_FOUND", "Vendor record was not found.");
+  }
+
+  return ok(response, entry, 201);
+});
diff --git a/server/src/modules/crm/service.ts b/server/src/modules/crm/service.ts
index e1856af..997c3d0 100644
--- a/server/src/modules/crm/service.ts
+++ b/server/src/modules/crm/service.ts
@@ -1,4 +1,7 @@
 import type {
+  CrmContactEntryDto,
+  CrmContactEntryInput,
+  CrmContactEntryType,
   CrmRecordDetailDto,
   CrmRecordInput,
   CrmRecordStatus,
@@ -30,6 +33,58 @@ function mapDetail(record: Customer | Vendor): CrmRecordDetailDto {
     postalCode: record.postalCode,
     notes: record.notes,
     createdAt: record.createdAt.toISOString(),
+    contactHistory: [],
+  };
+}
+
+type ContactEntryWithAuthor = {
+  id: string;
+  type: string;
+  summary: string;
+  body: string;
+  contactAt: Date;
+  createdAt: Date;
+  createdBy: {
+    id: string;
+    firstName: string;
+    lastName: string;
+    email: string;
+  } | null;
+};
+
+type DetailedRecord = (Customer | Vendor) & {
+  contactEntries: ContactEntryWithAuthor[];
+};
+
+function mapContactEntry(entry: ContactEntryWithAuthor): CrmContactEntryDto {
+  return {
+    id: entry.id,
+    type: entry.type as CrmContactEntryType,
+    summary: entry.summary,
+    body: entry.body,
+    contactAt: entry.contactAt.toISOString(),
+    createdAt: entry.createdAt.toISOString(),
+    createdBy: entry.createdBy
+      ? {
+          id: entry.createdBy.id,
+          name: `${entry.createdBy.firstName} ${entry.createdBy.lastName}`.trim(),
+          email: entry.createdBy.email,
+        }
+      : {
+          id: null,
+          name: "System",
+          email: null,
+        },
+  };
+}
+
+function mapDetailedRecord(record: DetailedRecord): CrmRecordDetailDto {
+  return {
+    ...mapDetail(record),
+    contactHistory: record.contactEntries
+      .slice()
+      .sort((left, right) => right.contactAt.getTime() - left.contactAt.getTime())
+      .map(mapContactEntry),
   };
 }
 
@@ -74,9 +129,17 @@ export async function listCustomers(filters: CrmListFilters = {}) {
 export async function getCustomerById(customerId: string) {
   const customer = await prisma.customer.findUnique({
     where: { id: customerId },
+    include: {
+      contactEntries: {
+        include: {
+          createdBy: true,
+        },
+        orderBy: [{ contactAt: "desc" }, { createdAt: "desc" }],
+      },
+    },
   });
 
-  return customer ? mapDetail(customer) : null;
+  return customer ? mapDetailedRecord(customer) : null;
 }
 
 export async function createCustomer(payload: CrmRecordInput) {
@@ -116,9 +179,17 @@ export async function listVendors(filters: CrmListFilters = {}) {
 export async function getVendorById(vendorId: string) {
   const vendor = await prisma.vendor.findUnique({
     where: { id: vendorId },
+    include: {
+      contactEntries: {
+        include: {
+          createdBy: true,
+        },
+        orderBy: [{ contactAt: "desc" }, { createdAt: "desc" }],
+      },
+    },
   });
 
-  return vendor ? mapDetail(vendor) : null;
+  return vendor ? mapDetailedRecord(vendor) : null;
 }
 
 export async function createVendor(payload: CrmRecordInput) {
@@ -145,3 +216,55 @@ export async function updateVendor(vendorId: string, payload: CrmRecordInput) {
 
   return mapDetail(vendor);
 }
+
+export async function createCustomerContactEntry(customerId: string, payload: CrmContactEntryInput, createdById?: string) {
+  const existingCustomer = await prisma.customer.findUnique({
+    where: { id: customerId },
+  });
+
+  if (!existingCustomer) {
+    return null;
+  }
+
+  const entry = await prisma.crmContactEntry.create({
+    data: {
+      type: payload.type,
+      summary: payload.summary,
+      body: payload.body,
+      contactAt: new Date(payload.contactAt),
+      customerId,
+      createdById,
+    },
+    include: {
+      createdBy: true,
+    },
+  });
+
+  return mapContactEntry(entry);
+}
+
+export async function createVendorContactEntry(vendorId: string, payload: CrmContactEntryInput, createdById?: string) {
+  const existingVendor = await prisma.vendor.findUnique({
+    where: { id: vendorId },
+  });
+
+  if (!existingVendor) {
+    return null;
+  }
+
+  const entry = await prisma.crmContactEntry.create({
+    data: {
+      type: payload.type,
+      summary: payload.summary,
+      body: payload.body,
+      contactAt: new Date(payload.contactAt),
+      vendorId,
+      createdById,
+    },
+    include: {
+      createdBy: true,
+    },
+  });
+
+  return mapContactEntry(entry);
+}
diff --git a/shared/src/crm/types.ts b/shared/src/crm/types.ts
index c3cdfb8..0ebb4ef 100644
--- a/shared/src/crm/types.ts
+++ b/shared/src/crm/types.ts
@@ -1,6 +1,29 @@
 export const crmRecordStatuses = ["LEAD", "ACTIVE", "ON_HOLD", "INACTIVE"] as const;
+export const crmContactEntryTypes = ["NOTE", "CALL", "EMAIL", "MEETING"] as const;
 
 export type CrmRecordStatus = (typeof crmRecordStatuses)[number];
+export type CrmContactEntryType = (typeof crmContactEntryTypes)[number];
+
+export interface CrmContactEntryDto {
+  id: string;
+  type: CrmContactEntryType;
+  summary: string;
+  body: string;
+  contactAt: string;
+  createdAt: string;
+  createdBy: {
+    id: string | null;
+    name: string;
+    email: string | null;
+  };
+}
+
+export interface CrmContactEntryInput {
+  type: CrmContactEntryType;
+  summary: string;
+  body: string;
+  contactAt: string;
+}
 
 export interface CrmRecordSummaryDto {
   id: string;
@@ -20,6 +43,7 @@ export interface CrmRecordDetailDto extends CrmRecordSummaryDto {
   postalCode: string;
   notes: string;
   createdAt: string;
+  contactHistory: CrmContactEntryDto[];
 }
 
 export interface CrmRecordInput {