diff --git a/frontend/src/lib/components/payments/PaymentModal.svelte b/frontend/src/lib/components/payments/PaymentModal.svelte
index 78ae079..1790184 100644
--- a/frontend/src/lib/components/payments/PaymentModal.svelte
+++ b/frontend/src/lib/components/payments/PaymentModal.svelte
@@ -271,6 +271,12 @@
 	let selectedTipPercent = $state<number | null>(null);
 	let customTipAmount = $state<string>('');
 
+	// Partial payment amounts for card and saved card (in pounds, user enters)
+	let cardPaymentAmount = $state<string>('');
+	let lastValidCardAmount = $state<string>('');
+	let savedCardPaymentAmount = $state<string>('');
+	let lastValidSavedCardAmount = $state<string>('');
+
 	let pollingInterval: ReturnType<typeof setInterval> | null = null;
 
 	function selectTipPercent(percent: number) {
@@ -289,6 +295,30 @@
 		tipEnabled = customTipAmount !== '' && parseFloat(customTipAmount) > 0;
 	}
 
+	function handleCardAmountInput(e: Event) {
+		const input = e.target as HTMLInputElement;
+		const sanitized = sanitizeDecimalInput(input.value);
+		if (sanitized === '' || /^\d+(\.\d{0,2})?$/.test(sanitized)) {
+			cardPaymentAmount = sanitized;
+			lastValidCardAmount = sanitized;
+		} else {
+			cardPaymentAmount = lastValidCardAmount;
+			input.value = lastValidCardAmount;
+		}
+	}
+
+	function handleSavedCardAmountInput(e: Event) {
+		const input = e.target as HTMLInputElement;
+		const sanitized = sanitizeDecimalInput(input.value);
+		if (sanitized === '' || /^\d+(\.\d{0,2})?$/.test(sanitized)) {
+			savedCardPaymentAmount = sanitized;
+			lastValidSavedCardAmount = sanitized;
+		} else {
+			savedCardPaymentAmount = lastValidSavedCardAmount;
+			input.value = lastValidSavedCardAmount;
+		}
+	}
+
 	function getServicePrice(service: BookingService): number {
 		const override = serviceOverrides[service.service_id];
 		if (override && override.price !== '') {
@@ -367,6 +397,56 @@
 	// disabled in that state; the handlers also guard defensively.
 	const nothingToCharge = $derived(totalDue <= 0);
 
+	// Card payment amount validation
+	const cardAmountNum = $derived(cardPaymentAmount === '' ? totalDue : parseFloat(cardPaymentAmount));
+	const cardAmountValid = $derived(
+		cardPaymentAmount === '' ||
+			(cardPaymentAmount !== '' &&
+				!isNaN(cardAmountNum) &&
+				cardAmountNum > 0 &&
+				cardAmountNum <= totalDue &&
+				/^\d+(\.\d{0,2})?$/.test(cardPaymentAmount))
+	);
+	const cardValidationError = $derived(
+		cardPaymentAmount !== '' && !cardAmountValid
+			? cardPaymentAmount === ''
+				? ''
+				: !/^\d+(\.\d{0,2})?$/.test(cardPaymentAmount)
+					? 'Enter a valid amount (max 2 decimal places)'
+					: cardAmountNum <= 0
+						? 'Amount must be greater than 0'
+						: cardAmountNum > totalDue
+							? `Amount cannot exceed ${formatCurrency(totalDue)}`
+							: ''
+			: ''
+	);
+
+	// Saved card payment amount validation
+	const savedCardAmountNum = $derived(
+		savedCardPaymentAmount === '' ? totalDue : parseFloat(savedCardPaymentAmount)
+	);
+	const savedCardAmountValid = $derived(
+		savedCardPaymentAmount === '' ||
+			(savedCardPaymentAmount !== '' &&
+				!isNaN(savedCardAmountNum) &&
+				savedCardAmountNum > 0 &&
+				savedCardAmountNum <= totalDue &&
+				/^\d+(\.\d{0,2})?$/.test(savedCardPaymentAmount))
+	);
+	const savedCardValidationError = $derived(
+		savedCardPaymentAmount !== '' && !savedCardAmountValid
+			? savedCardPaymentAmount === ''
+				? ''
+				: !/^\d+(\.\d{0,2})?$/.test(savedCardPaymentAmount)
+					? 'Enter a valid amount (max 2 decimal places)'
+					: savedCardAmountNum <= 0
+						? 'Amount must be greater than 0'
+						: savedCardAmountNum > totalDue
+							? `Amount cannot exceed ${formatCurrency(totalDue)}`
+							: ''
+			: ''
+	);
+
 	async function applyLoyaltyRedemption(): Promise<void> {
 		if (!useLoyalty) return;
 		const res = await apiFetch(`/api/admin/bookings/${booking.id}/apply-redemption`, {
@@ -381,12 +461,16 @@
 
 	async function handleCardPayment() {
 		if (isProcessingPaymentSync) return;
-		const finalAmount = totalDue;
+		const finalAmount = cardAmountNum;
 
 		if (isNaN(finalAmount) || finalAmount <= 0) {
 			toast.error('Please enter a valid amount');
 			return;
 		}
+		if (finalAmount > totalDue) {
+			toast.error(`Amount cannot exceed ${formatCurrency(totalDue)}`);
+			return;
+		}
 		// The loyalty redemption is applied on top of totalDue; guard against
 		// the effective charge being zero or negative.
 		if (Math.round(finalAmount * 100) - loyaltyDiscount <= 0) {
@@ -837,7 +921,16 @@
 			return;
 		}
 
-		const chargeAmount = Math.round(totalDue * 100) - loyaltyDiscount;
+		const chargeAmount = Math.round(savedCardAmountNum * 100) - loyaltyDiscount;
+
+		if (isNaN(savedCardAmountNum) || savedCardAmountNum <= 0) {
+			toast.error('Please enter a valid amount');
+			return;
+		}
+		if (savedCardAmountNum > totalDue) {
+			toast.error(`Amount cannot exceed ${formatCurrency(totalDue)}`);
+			return;
+		}
 
 		// totalDue can be £0 (fully discounted) and the loyalty discount is
 		// applied on top — the effective charge could otherwise be 0 or negative.
@@ -1446,10 +1539,40 @@
 					</div>
 				{/if}
 
+				<div>
+					<label for="card-amount" class="text-sm font-medium text-gray-700">
+						Amount to Charge
+					</label>
+					<div class="relative mt-1">
+						<span class="absolute top-1/2 left-3 -translate-y-1/2 text-gray-500">£</span>
+						<Input
+							id="card-amount"
+							type="text"
+							inputmode="decimal"
+							step="0.01"
+							placeholder={totalDue.toFixed(2)}
+							value={cardPaymentAmount}
+							oninput={handleCardAmountInput}
+							class="pl-7"
+							disabled={status !== 'selecting'}
+						/>
+					</div>
+					{#if cardValidationError}
+						<p class="mt-1 text-sm text-red-600">{cardValidationError}</p>
+					{/if}
+					<p class="mt-1 text-xs text-gray-500">
+						Leave blank to charge full amount ({formatCurrency(totalDue)})
+					</p>
+				</div>
+
 				<div class="flex gap-3">
 					<Button variant="ghost" onclick={resetToSelect} class="min-h-11 flex-1">Back</Button>
-					<Button onclick={handleCardPayment} class="min-h-11 flex-1" disabled={nothingToCharge}>
-						Charge Card
+					<Button
+						onclick={handleCardPayment}
+						class="min-h-11 flex-1"
+						disabled={nothingToCharge || !cardAmountValid}
+					>
+						{cardPaymentAmount === '' ? 'Charge Card' : `Charge ${formatCurrency(cardAmountNum)}`}
 					</Button>
 				</div>
 			</div>
@@ -1710,14 +1833,46 @@
 					}}
 				/>
 
+				{#if selectedSavedCardId}
+					<div>
+						<label for="saved-card-amount" class="text-sm font-medium text-gray-700">
+							Amount to Charge
+						</label>
+						<div class="relative mt-1">
+							<span class="absolute top-1/2 left-3 -translate-y-1/2 text-gray-500">£</span>
+							<Input
+								id="saved-card-amount"
+								type="text"
+								inputmode="decimal"
+								step="0.01"
+								placeholder={totalDue.toFixed(2)}
+								value={savedCardPaymentAmount}
+								oninput={handleSavedCardAmountInput}
+								class="pl-7"
+								disabled={status !== 'saved-card-selecting'}
+							/>
+						</div>
+						{#if savedCardValidationError}
+							<p class="mt-1 text-sm text-red-600">{savedCardValidationError}</p>
+						{/if}
+						<p class="mt-1 text-xs text-gray-500">
+							Leave blank to charge full amount ({formatCurrency(totalDue)})
+						</p>
+					</div>
+				{/if}
+
 				<div class="flex gap-3">
 					<Button variant="ghost" onclick={resetToSelect} class="min-h-11 flex-1">Back</Button>
 					<Button
 						onclick={handleSavedCardPayment}
 						class="min-h-11 flex-1"
-						disabled={!selectedSavedCardId || nothingToCharge}
+						disabled={
+							!selectedSavedCardId || nothingToCharge || !savedCardAmountValid
+						}
 					>
-						Charge Saved Card
+						{savedCardPaymentAmount === ''
+							? 'Charge Saved Card'
+							: `Charge ${formatCurrency(savedCardAmountNum)}`}
 					</Button>
 				</div>
 			</div>