Updated Price Model TaxIncl methods & Cart Item TaxIncl properties to actually provide Tax inclusive values.

packages/core/src/Base/TaxDriver.php

@@ -5,6 +5,7 @@
 use Lunar\Base\ValueObjects\Cart\TaxBreakdown;
 use Lunar\Models\Contracts\CartLine;
 use Lunar\Models\Contracts\Currency;
+use Lunar\Models\Contracts\TaxZone;
 
 interface TaxDriver
 {
@@ -33,6 +34,15 @@ public function setPurchasable(Purchasable $purchasable): self;
      */
     public function setCartLine(CartLine $cartLine): self;
 
+    /**
+     * Set a tax zone override.
+     *
+     * When provided, this zone is used directly instead of resolving one from the shipping address, allowing
+     * the developer to handle cases like taxation on IP address basis. Just set the tax zone as and let it
+     * flow smoothly.
+     */
+    public function setTaxZone(?TaxZone $taxZone = null): self;
+
     /**
      * Return the tax breakdown from a given sub total.
      *

packages/core/src/Drivers/SystemTaxDriver.php

@@ -11,6 +11,7 @@
 use Lunar\DataTypes\Price;
 use Lunar\Models\Contracts\CartLine;
 use Lunar\Models\Contracts\Currency;
+use Lunar\Models\Contracts\TaxZone as TaxZoneContract;
 use Lunar\Models\TaxZone;
 use Spatie\LaravelBlink\BlinkFacade as Blink;
 
@@ -41,6 +42,12 @@ class SystemTaxDriver implements TaxDriver
      */
     protected ?CartLine $cartLine = null;
 
+    /**
+     * An optional tax zone override supplied at the cart level.
+     * When set this takes precedence over the address-derived zone.
+     */
+    protected ?TaxZoneContract $taxZone = null;
+
     /**
      * {@inheritDoc}
      */
@@ -91,12 +98,22 @@ public function setCartLine(CartLine $cartLine): self
         return $this;
     }
 
+    /**
+     * {@inheritDoc}
+     */
+    public function setTaxZone(?TaxZoneContract $taxZone = null): self
+    {
+        $this->taxZone = $taxZone;
+
+        return $this;
+    }
+
     /**
      * {@inheritDoc}
      */
     public function getBreakdown($subTotal): TaxBreakdown
     {
-        $taxZone = app(GetTaxZone::class)->execute($this->shippingAddress);
+        $taxZone = $this->taxZone ?? app(GetTaxZone::class)->execute($this->shippingAddress);
         $taxClass = $this->purchasable->getTaxClass();
 
         $taxAmounts = Blink::once('tax_zone_rates_'.$taxZone->id.'_'.$taxClass->id, function () use ($taxClass, $taxZone) {

packages/core/src/Models/Cart.php

@@ -41,6 +41,8 @@
 use Lunar\Exceptions\FingerprintMismatchException;
 use Lunar\Facades\DB;
 use Lunar\Facades\ShippingManifest;
+use Lunar\Models\TaxZone;
+use Spatie\LaravelBlink\BlinkFacade as Blink;
 use Lunar\Pipelines\Cart\Calculate;
 use Lunar\Validation\Cart\ValidateCartForOrderCreation;
 use Lunar\Validation\CartLine\CartLineStock;
@@ -67,6 +69,22 @@ class Cart extends BaseModel implements Contracts\Cart
     use LogsActivity;
     use SoftDeletes;
 
+    /** Restore the tax zone override from the cart's meta JSON column whenever a Cart is loaded from the database. */
+    protected static function booted(): void
+    {
+        parent::booted();
+
+        static::retrieved(function (Cart $cart) {
+            $taxZoneId = $cart->meta['tax_zone_id'] ?? null;
+            if ($taxZoneId) {
+                $cart->taxZone = Blink::once(
+                    'cart_tax_zone_'.$taxZoneId,
+                    fn () => TaxZone::find($taxZoneId)
+                );
+            }
+        });
+    }
+
     /**
      * Array of cachable class properties.
      *
@@ -138,6 +156,15 @@ class Cart extends BaseModel implements Contracts\Cart
      */
     public ?ShippingOption $shippingOptionOverride = null;
 
+    /**
+     * The tax zone override for this cart.
+     * When set, this zone will be used instead of resolving a zone from the
+     * shipping address, enabling middleware to enforce the correct geographic
+     * tax treatment based on IP geo-location or customer-provided country
+     * before a full shipping address is known.
+     */
+    public ?TaxZone $taxZone = null;
+
     /**
      * Additional shipping estimate meta data.
      */
@@ -617,4 +644,29 @@ public function getEstimatedShipping(array $params, bool $setOverride = false):
 
         return $option;
     }
+
+    /**
+     * Set the tax zone override for this cart.
+     *
+     * When set, all tax calculations will use this zone instead of resolving one from the shipping address.
+     * Pass null to clear the override and fall back to the address-derived (or default) zone.
+     *
+     * The zone ID is mirrored into the cart's `meta` JSON column so the choice survives across requests.
+     * Call `->save()` afterwards to persist it to the database; the `booted()` retrieved-event listener
+     * will then restore the zone automatically on every subsequent page load.
+     */
+    public function setTaxZone(?TaxZone $taxZone): Cart
+    {
+        $this->taxZone = $taxZone;
+        $meta = $this->meta ?? new \ArrayObject;
+
+        if ($taxZone) {
+            $meta['tax_zone_id'] = $taxZone->id;
+        } else {
+            unset($meta['tax_zone_id']);
+        }
+
+        $this->meta = $meta;
+        return $this;
+    }
 }

packages/core/src/Models/CartLine.php

@@ -40,6 +40,7 @@ class CartLine extends BaseModel implements Contracts\CartLine
      */
     public $cachableProperties = [
         'unitPrice',
+        'unitPriceInclTax',
         'subTotal',
         'discountTotal',
         'taxAmount',

packages/core/src/Models/Contracts/Price.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\MorphTo;
+use Lunar\Models\TaxZone;
 
 interface Price
 {
@@ -24,11 +25,22 @@ public function customerGroup(): BelongsTo;
 
     /**
      * Return the price exclusive of tax.
+     *
+     * @param  TaxZone|null  $taxZone
      */
-    public function priceExTax(): \Lunar\DataTypes\Price;
+    public function priceExTax(?TaxZone $taxZone = null): \Lunar\DataTypes\Price;
 
     /**
      * Return the price inclusive of tax.
+     *
+     * @param  TaxZone|null  $taxZone
      */
-    public function priceIncTax(): int|\Lunar\DataTypes\Price;
+    public function priceIncTax(?TaxZone $taxZone = null): int|\Lunar\DataTypes\Price;
+
+    /**
+     * Return the compare price inclusive of tax.
+     *
+     * @param  TaxZone|null  $taxZone
+     */
+    public function comparePriceIncTax(?TaxZone $taxZone = null): int|\Lunar\DataTypes\Price;
 }

packages/core/src/Models/Price.php

@@ -75,59 +75,77 @@ public function customerGroup(): BelongsTo
 
     /**
      * Return the price exclusive of tax.
+     *
+     * @param  TaxZone|null  $taxZone  Optional override for the tax zone. Falls back to the
+     *                                 Blink cart override, then the store's default zone.
      */
-    public function priceExTax(): \Lunar\DataTypes\Price
+    public function priceExTax(?TaxZone $taxZone = null): \Lunar\DataTypes\Price
     {
         if (! prices_inc_tax()) {
             return $this->price;
         }
 
         $priceExTax = clone $this->price;
 
-        $priceExTax->value = (int) round($priceExTax->value / (1 + $this->getPriceableTaxRate()));
+        $priceExTax->value = (int) round($priceExTax->value / (1 + $this->getPriceableTaxRate($taxZone)));
 
         return $priceExTax;
     }
 
     /**
      * Return the price inclusive of tax.
+     *
+     * @param  TaxZone|null  $taxZone  Optional override for the tax zone.
      */
-    public function priceIncTax(): int|\Lunar\DataTypes\Price
+    public function priceIncTax(?TaxZone $taxZone = null): int|\Lunar\DataTypes\Price
     {
         if (prices_inc_tax()) {
             return $this->price;
         }
 
         $priceIncTax = clone $this->price;
-        $priceIncTax->value = (int) round($priceIncTax->value * (1 + $this->getPriceableTaxRate()));
+        $priceIncTax->value = (int) round($priceIncTax->value * (1 + $this->getPriceableTaxRate($taxZone)));
 
         return $priceIncTax;
     }
 
     /**
      * Return the compare price inclusive of tax.
+     *
+     * @param  TaxZone|null  $taxZone  Optional override for the tax zone.
      */
-    public function comparePriceIncTax(): int|\Lunar\DataTypes\Price
+    public function comparePriceIncTax(?TaxZone $taxZone = null): int|\Lunar\DataTypes\Price
     {
         if (prices_inc_tax()) {
             return $this->compare_price;
         }
 
         $comparePriceIncTax = clone $this->compare_price;
-        $comparePriceIncTax->value = (int) round($comparePriceIncTax->value * (1 + $this->getPriceableTaxRate()));
+        $comparePriceIncTax->value = (int) round($comparePriceIncTax->value * (1 + $this->getPriceableTaxRate($taxZone)));
 
         return $comparePriceIncTax;
     }
 
     /**
-     * Return the total tax rate amount within the predefined tax zone for the related priceable
+     * Return the total tax rate percentage (as a decimal, e.g. 0.20 for 20 %) for the given
+     * tax zone + priceable's own tax class combination.
+     *
+     * Resolution order
+     * ─ Tax class : always from the priceable (product-level classification, never overridden here)
+     * ─ Tax zone  : explicit param → Blink cart override (lunar_cart_tax_zone) → store default zone
+     *
+     * Results are cached in Blink keyed by "{classId}_{zoneId}" so different combinations
+     * never collide within the same request.
      */
-    protected function getPriceableTaxRate(): int|float
+    protected function getPriceableTaxRate(?TaxZone $taxZone = null): int|float
     {
-        return Blink::once('price_tax_rate_'.$this->priceable->getTaxClass()->id, function () {
-            $taxZone = TaxZone::where('default', '=', 1)->first();
+        $taxClass = $this->priceable->getTaxClass();
+        $taxZone ??= Blink::get('lunar_cart_tax_zone')
+            ?? Blink::once('lunar_default_tax_zone', fn () => TaxZone::where('default', '=', 1)->first());
+        $cacheKey = 'price_tax_rate_'.$taxClass->id.'_'.($taxZone?->id ?? 'none');
 
-            if ($taxZone && ! is_null($taxClass = $this->priceable->getTaxClass())) {
+        return Blink::once($cacheKey, function () use ($taxClass, $taxZone) {
+            if ($taxZone && $taxClass) {
                 return $taxClass->taxRateAmounts
                     ->whereIn('tax_rate_id', $taxZone->taxRates->pluck('id'))
                     ->sum('percentage') / 100;

packages/core/src/Pipelines/Cart/CalculateLines.php

@@ -7,6 +7,7 @@
 use Lunar\DataTypes\Price;
 use Lunar\Models\Cart;
 use Lunar\Models\Contracts\Cart as CartContract;
+use Spatie\LaravelBlink\BlinkFacade as Blink;
 
 class CalculateLines
 {
@@ -18,6 +19,14 @@ class CalculateLines
     public function handle(CartContract $cart, Closure $next): mixed
     {
         /** @var Cart $cart */
+
+        // Cache the TaxZone so that price model taxInc methods accounts for it in computation.
+        if ($cart->taxZone) {
+            Blink::put('lunar_cart_tax_zone', $cart->taxZone);
+        } else {
+            Blink::forget('lunar_cart_tax_zone');
+        }
+
         foreach ($cart->lines as $line) {
             $cartLine = app(Pipeline::class)
                 ->send($line)

packages/core/src/Pipelines/Cart/CalculateTax.php

@@ -37,6 +37,7 @@ public function handle(CartContract $cart, Closure $next): mixed
                 ->setCurrency($cart->currency)
                 ->setPurchasable($cartLine->purchasable)
                 ->setCartLine($cartLine)
+                ->setTaxZone($cart->taxZone)
                 ->getBreakdown($subTotal);
 
             $taxBreakDownAmounts = $taxBreakDownAmounts->merge(
@@ -70,6 +71,7 @@ public function handle(CartContract $cart, Closure $next): mixed
             $shippingTax = Taxes::setShippingAddress($cart->shippingAddress)
                 ->setCurrency($cart->currency)
                 ->setPurchasable($shippingOption)
+                ->setTaxZone($cart->taxZone)
                 ->getBreakdown($shippingSubTotal);
 
             $shippingTaxTotal = $shippingTax->amounts->sum('price.value');