diff --git a/src/components/UploadPage.tsx b/src/components/UploadPage.tsx
index c444f3b..773f556 100644
--- a/src/components/UploadPage.tsx
+++ b/src/components/UploadPage.tsx
@@ -117,12 +117,12 @@ export function UploadPage({
                   <UploadIcon size={40} className="fill-fg-muted" aria-hidden />
                 </div>
                 <h3 className="m-0 font-semibold text-fg-default text-[18px] sm:text-[20px]">Drop your CSV here or click to browse</h3>
-                <p className="m-0 text-fg-muted text-[14px]">premiumRequestUsageReport_*.csv</p>
+                <p className="m-0 text-fg-muted text-[14px]">April or May PRU vs usage-based billing CSV</p>
               </>
             )}
           </div>
         </section>
-        <p className="mt-4 mb-0 text-fg-muted text-[13px]">Accepted: .csv files from the Premium Request Usage report</p>
+        <p className="mt-4 mb-0 text-fg-muted text-[13px]">Accepted: April and May PRU vs usage-based billing reports</p>
         <section className="mt-6 px-6 py-5 text-left border border-border-default rounded-lg bg-bg-muted" aria-label="Privacy notice">
           <h4 className="m-0 mb-3 flex items-center gap-2 text-[16px] text-fg-default">
             <LockIcon size={16} className="text-app-savings-fg" aria-hidden />
diff --git a/src/pipeline/parser.test.ts b/src/pipeline/parser.test.ts
index afa5ffa..334cc22 100644
--- a/src/pipeline/parser.test.ts
+++ b/src/pipeline/parser.test.ts
@@ -7,8 +7,10 @@ import {
   parseNormalizedTokenUsageRecord,
   parseTokenUsageHeader,
   parseTokenUsageRecord,
+  UnsupportedNativeAiCreditsReportError,
   UnsupportedReportVersionError,
   validateHeader,
+  validateSupportedReportRecord,
 } from './parser'
 
 const FULL_HEADER = [
@@ -759,3 +761,62 @@ describe('validateHeader', () => {
     expect(() => validateHeader(header)).toThrow(InvalidReportError)
   })
 })
+
+describe('validateSupportedReportRecord', () => {
+  it('throws a clear error for the native AI Credits report format', () => {
+    const header = parseTokenUsageHeader(HEADER_WITHOUT_EXCEEDS_QUOTA)
+    const record = parseTokenUsageRecord(
+      buildRow([
+        '5/29/26',
+        'mona',
+        'copilot',
+        'copilot_ai_credit',
+        'Auto: Claude Haiku 4.5',
+        '96.9990345',
+        'ai-credits',
+        '0.01',
+        '0.969990345',
+        '0',
+        '0.969990345',
+        '3900',
+        'example-org',
+        '',
+        '96.9990345',
+        '0.969990345',
+      ]),
+      header,
+    )
+
+    expect(() => validateSupportedReportRecord(header, record)).toThrow(UnsupportedNativeAiCreditsReportError)
+    expect(() => validateSupportedReportRecord(header, record)).toThrow(
+      'currently supports PRU vs usage-based billing reports generated for the April and May billing periods',
+    )
+  })
+
+  it('accepts PRU report rows when exceeds_quota is absent', () => {
+    const header = parseTokenUsageHeader(HEADER_WITHOUT_EXCEEDS_QUOTA)
+    const record = parseTokenUsageRecord(
+      buildRow([
+        '2026-05-29',
+        'mona',
+        'copilot',
+        'copilot_premium_request',
+        'Auto: Claude Haiku 4.5',
+        '2',
+        'requests',
+        '0.04',
+        '0.08',
+        '0',
+        '0.08',
+        '300',
+        'example-org',
+        'Cost Center A',
+        '20',
+        '0.20',
+      ]),
+      header,
+    )
+
+    expect(() => validateSupportedReportRecord(header, record)).not.toThrow()
+  })
+})
diff --git a/src/pipeline/parser.ts b/src/pipeline/parser.ts
index b60d775..7e9e96f 100644
--- a/src/pipeline/parser.ts
+++ b/src/pipeline/parser.ts
@@ -138,6 +138,17 @@ export class UnsupportedReportVersionError extends Error {
   }
 }
 
+export class UnsupportedNativeAiCreditsReportError extends Error {
+  constructor() {
+    super(
+      `This billing preview app currently supports PRU vs usage-based billing reports generated for ` +
+        `the April and May billing periods. Reports generated on or after June 1 use AI Credits as ` +
+        `the primary unit and are not supported yet.`,
+    )
+    this.name = 'UnsupportedNativeAiCreditsReportError'
+  }
+}
+
 export function validateHeader(header: TokenUsageHeader): void {
   const missingBase = BASE_BILLING_COLUMNS.filter((col) => !(col in header.index))
   if (missingBase.length > 0) {
@@ -150,6 +161,15 @@ export function validateHeader(header: TokenUsageHeader): void {
   }
 }
 
+export function validateSupportedReportRecord(header: TokenUsageHeader, record: TokenUsageRecord): void {
+  const lacksExceedsQuota = !('exceeds_quota' in header.index)
+  const usesNativeAiCreditsUnit = record.unit_type === 'ai-credits' && record.sku.endsWith('_ai_credit')
+
+  if (lacksExceedsQuota && usesNativeAiCreditsUnit) {
+    throw new UnsupportedNativeAiCreditsReportError()
+  }
+}
+
 function stripBom(s: string): string {
   return s.replace(/^\uFEFF/, '')
 }
diff --git a/src/pipeline/runPipeline.test.ts b/src/pipeline/runPipeline.test.ts
index 43b5fa4..1bbdb09 100644
--- a/src/pipeline/runPipeline.test.ts
+++ b/src/pipeline/runPipeline.test.ts
@@ -24,8 +24,27 @@ const HEADER = [
   'aic_gross_amount',
 ].join(',')
 
-function createCsv(rows: string[][]): File {
-  const body = [HEADER, ...rows.map((row) => row.join(','))].join('\n')
+const NATIVE_AI_CREDITS_HEADER = [
+  'date',
+  'username',
+  'product',
+  'sku',
+  'model',
+  'quantity',
+  'unit_type',
+  'applied_cost_per_quantity',
+  'gross_amount',
+  'discount_amount',
+  'net_amount',
+  'total_monthly_quota',
+  'organization',
+  'cost_center_name',
+  'aic_quantity',
+  'aic_gross_amount',
+].join(',')
+
+function createCsv(rows: string[][], header = HEADER): File {
+  const body = [header, ...rows.map((row) => row.join(','))].join('\n')
   return new File([body], 'usage.csv', { type: 'text/csv' })
 }
 
@@ -45,7 +64,36 @@ class CaptureAggregator implements Aggregator<TokenUsageRecord, TokenUsageRecord
   }
 }
 
-describe('runPipeline progress', () => {
+describe('runPipeline', () => {
+  it('rejects native AI Credits reports before processing rows', async () => {
+    const file = createCsv([
+      [
+        '5/29/26',
+        'mona',
+        'copilot',
+        'copilot_ai_credit',
+        'Auto: Claude Haiku 4.5',
+        '96.9990345',
+        'ai-credits',
+        '0.01',
+        '0.969990345',
+        '0',
+        '0.969990345',
+        '3900',
+        'example-org',
+        '',
+        '96.9990345',
+        '0.969990345',
+      ],
+    ], NATIVE_AI_CREDITS_HEADER)
+    const aggregator = new CaptureAggregator()
+
+    await expect(runPipeline(file, [aggregator])).rejects.toThrow(
+      'currently supports PRU vs usage-based billing reports generated for the April and May billing periods',
+    )
+    expect(aggregator.result()).toEqual([])
+  })
+
   it('filters and normalizes known normalization window rows before AIC allocation', async () => {
     const file = createCsv([
       ['2026-04-25', 'mona', 'copilot', 'copilot_premium_request', 'GPT-5', '0', 'requests', '0.04', '0', '0', '0', 'False', '300', '', '', '0', '0'],
diff --git a/src/pipeline/runPipeline.ts b/src/pipeline/runPipeline.ts
index 08dbb7e..d5ce7ea 100644
--- a/src/pipeline/runPipeline.ts
+++ b/src/pipeline/runPipeline.ts
@@ -3,19 +3,31 @@ import { createAicIncludedCreditsAllocator, type AicIncludedCreditsOverrides } f
 import {
   parseTokenUsageHeader,
   parseNormalizedTokenUsageRecord,
+  parseTokenUsageRecord,
+  validateSupportedReportRecord,
   validateHeader,
   type TokenUsageHeader,
   type TokenUsageRecord,
 } from './parser'
 import { streamLines, type StreamProgress } from './streamer'
 
-async function validateFileHeader(file: File): Promise<void> {
+async function validateFileFormat(file: File): Promise<void> {
+  let header: TokenUsageHeader | null = null
+
   for await (const line of streamLines(file)) {
     const trimmed = line.trimEnd()
-    if (trimmed) {
-      validateHeader(parseTokenUsageHeader(trimmed))
-      return
+    if (!trimmed) {
+      continue
     }
+
+    if (!header) {
+      header = parseTokenUsageHeader(trimmed)
+      validateHeader(header)
+      continue
+    }
+
+    validateSupportedReportRecord(header, parseTokenUsageRecord(trimmed, header))
+    return
   }
 }
 
@@ -67,7 +79,7 @@ export async function runPipeline(
   options?: PipelineOptions,
 ): Promise<PipelineResult> {
   const { includedCreditsOverrides = {}, progressResolution = 500, onProgress } = options ?? {}
-  await validateFileHeader(file)
+  await validateFileFormat(file)
   let lastProgressStage: PipelineProgress['stage'] | null = null
   let lastProgressPercent = -1
   let lastProgressTimestamp = 0