diff --git a/components/js-api-client/package.json b/components/js-api-client/package.json
index 925cd27f..c027d982 100644
--- a/components/js-api-client/package.json
+++ b/components/js-api-client/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@crystallize/js-api-client",
     "license": "MIT",
-    "version": "2.4.0",
+    "version": "2.5.0",
     "author": "Crystallize <hello@crystallize.com> (https://crystallize.com)",
     "contributors": [
         "Sébastien Morel <sebastien@crystallize.com>",
diff --git a/components/js-api-client/src/core/pricing.ts b/components/js-api-client/src/core/pricing.ts
index 9a99670d..8f69fdf1 100644
--- a/components/js-api-client/src/core/pricing.ts
+++ b/components/js-api-client/src/core/pricing.ts
@@ -1,50 +1,54 @@
 import { Prices, Tier } from '../types/pricing';
 
 export function pricesForUsageOnTier(usage: number, tiers: Tier[], tierType: 'volume' | 'graduated'): Prices {
-    const sortedTiers = [...tiers].sort((a: Tier, b: Tier) => a.threshold - b.threshold);
+    const sortedTiers = tiers.sort((a: Tier, b: Tier) => a.threshold - b.threshold);
+    // let's add the implicit tiers id it does not exists
+    if (sortedTiers[0].threshold > 0) {
+        sortedTiers.unshift({ threshold: 0, price: 0, currency: tiers[0].currency });
+    }
 
     if (tierType === 'volume') {
-        return volumeBasedPriceFor(usage, sortedTiers);
+        return volumeBasedPriceFor(Math.max(0, usage), sortedTiers);
     }
     return graduatedBasedPriceFor(usage, sortedTiers);
 }
 
 function volumeBasedPriceFor(usage: number, tiers: Tier[]): Prices {
+    const freeUsage = tiers.reduce((memo: number, tier: Tier, tierIndex) => {
+        if (tier.price === 0) {
+            return tiers[tierIndex + 1]?.threshold || 0;
+        }
+        return memo;
+    }, 0);
+    const forCalculationUsage = Math.max(0, usage - freeUsage);
     const tiersLength = tiers.length;
-
     for (let i = tiersLength - 1; i >= 0; i--) {
         const tier: Tier = tiers[i];
         if (usage < tier.threshold && i > 0) {
             continue;
         }
-        // manage also an inexistent tier (threshold = 0)
-        return { [tier.currency]: (usage >= tier.threshold ? tier.price : 0) * usage };
+        return { [tier.currency]: (usage >= tier.threshold ? tier.price || 0 : 0) * forCalculationUsage };
     }
     return { USD: 0.0 };
 }
 
 function graduatedBasedPriceFor(usage: number, tiers: Tier[]): Prices {
     let rest = usage;
-
-    // manage also an inexistent tier (threshold = 0)
-    if (tiers[0].threshold > 0) {
-        rest = Math.max(0, rest - (tiers[0].threshold - 1));
-    }
-
     const splitUsage: Array<Tier & { usage: number }> = tiers.map((tier: Tier, tierIndex: number) => {
-        const limit = tiers[tierIndex + 1]?.threshold || Infinity;
-        const tierUsage = rest > limit ? limit : rest;
+        const currentThreshold = tier.threshold;
+        const nextThreshold = tiers[tierIndex + 1]?.threshold;
+        const maxTierUsage = nextThreshold ? nextThreshold - currentThreshold : Infinity;
+        const tierUsage = rest <= maxTierUsage ? rest : maxTierUsage;
         rest -= tierUsage;
         return {
             ...tier,
             usage: tierUsage,
         };
     });
-
     return splitUsage.reduce((memo: Prices, tier: Tier & { usage: number }) => {
         return {
             ...memo,
-            [tier.currency]: (memo[tier.currency] || 0.0) + tier.usage * tier.price,
+            [tier.currency]: (memo[tier.currency] || 0.0) + tier.usage * (tier.price || 0),
         };
     }, {});
 }
diff --git a/components/js-api-client/tests/pricesForUsageOnTier.test.js b/components/js-api-client/tests/pricesForUsageOnTier.test.js
index f5c49f4d..5855d161 100644
--- a/components/js-api-client/tests/pricesForUsageOnTier.test.js
+++ b/components/js-api-client/tests/pricesForUsageOnTier.test.js
@@ -102,26 +102,97 @@ const tiers5 = [
 
 test('Price For Volume', () => {
     expect(pricesForUsageOnTier(0, tiers1, 'volume')).toEqual({ EUR: 0 });
-    expect(pricesForUsageOnTier(2, tiers1, 'volume')).toEqual({ EUR: 500 });
-    expect(pricesForUsageOnTier(3, tiers1, 'volume')).toEqual({ EUR: 750 });
-    expect(pricesForUsageOnTier(20, tiers1, 'volume')).toEqual({ EUR: 400 });
-    expect(pricesForUsageOnTier(40, tiers1, 'volume')).toEqual({ EUR: 800 });
-
+    expect(pricesForUsageOnTier(2, tiers1, 'volume')).toEqual({ EUR: 0 }); // 2 are still free
+    expect(pricesForUsageOnTier(3, tiers1, 'volume')).toEqual({ EUR: 250 }); // we pay for 1
+    expect(pricesForUsageOnTier(20, tiers1, 'volume')).toEqual({ EUR: 360 }); // 20$ bracket but 2 free
+    expect(pricesForUsageOnTier(40, tiers1, 'volume')).toEqual({ EUR: 760 }); // 20$ bracket but 2 free
     expect(pricesForUsageOnTier(3, tiers2, 'volume')).toEqual({ EUR: 0 });
     expect(pricesForUsageOnTier(14, tiers2, 'volume')).toEqual({ EUR: 0 });
-    expect(pricesForUsageOnTier(15, tiers2, 'volume')).toEqual({ EUR: 7500 });
-    expect(pricesForUsageOnTier(16, tiers2, 'volume')).toEqual({ EUR: 8000 });
-    expect(pricesForUsageOnTier(30, tiers2, 'volume')).toEqual({ EUR: 9000 });
-    expect(pricesForUsageOnTier(31, tiers2, 'volume')).toEqual({ EUR: 9300 });
-    expect(pricesForUsageOnTier(40, tiers2, 'volume')).toEqual({ EUR: 4000 });
-    expect(pricesForUsageOnTier(41, tiers2, 'volume')).toEqual({ EUR: 4100 });
-    expect(pricesForUsageOnTier(131, tiers2, 'volume')).toEqual({ EUR: 13100 });
+    expect(pricesForUsageOnTier(15, tiers2, 'volume')).toEqual({ EUR: 0 });
+    expect(pricesForUsageOnTier(16, tiers2, 'volume')).toEqual({ EUR: 500 });
+    expect(pricesForUsageOnTier(30, tiers2, 'volume')).toEqual({ EUR: 4500 });
+    expect(pricesForUsageOnTier(31, tiers2, 'volume')).toEqual({ EUR: 4800 });
+    expect(pricesForUsageOnTier(40, tiers2, 'volume')).toEqual({ EUR: 2500 });
+    expect(pricesForUsageOnTier(41, tiers2, 'volume')).toEqual({ EUR: 2600 });
+    expect(pricesForUsageOnTier(131, tiers2, 'volume')).toEqual({ EUR: 11600 });
 });
 
-test('Price For Graduated', () => {
+test.only('Price For Graduated', () => {
     expect(pricesForUsageOnTier(4, tiers3, 'graduated')).toEqual({ EUR: 19 });
-    expect(pricesForUsageOnTier(211, tiers3, 'graduated')).toEqual({ EUR: 368 });
+    expect(pricesForUsageOnTier(211, tiers3, 'graduated')).toEqual({ EUR: 304 });
     expect(pricesForUsageOnTier(14, tiers4, 'graduated')).toEqual({ EUR: 0 });
     expect(pricesForUsageOnTier(15, tiers5, 'graduated')).toEqual({ EUR: 0 });
-    expect(pricesForUsageOnTier(25, tiers5, 'graduated')).toEqual({ EUR: 2 });
+    expect(pricesForUsageOnTier(25, tiers5, 'graduated')).toEqual({ EUR: 0 });
+    expect(pricesForUsageOnTier(26, tiers5, 'graduated')).toEqual({ EUR: 2 });
+});
+
+test('Test 3/21/2024 - with existing minimum', () => {
+    const tiers = [
+        {
+            threshold: 0,
+            price: 0,
+            currency: 'EUR',
+        },
+        {
+            threshold: 10,
+            price: 5,
+            currency: 'EUR',
+        },
+        {
+            threshold: 30,
+            price: 3,
+            currency: 'EUR',
+        },
+    ];
+    expect(pricesForUsageOnTier(42, tiers, 'graduated')).toEqual({ EUR: 136 });
+    expect(pricesForUsageOnTier(42, tiers, 'volume')).toEqual({ EUR: 96 });
+});
+
+test('Test 3/21/2024 - without existing minimum', () => {
+    const tiers = [
+        {
+            threshold: 10,
+            price: 5,
+            currency: 'EUR',
+        },
+        {
+            threshold: 30,
+            price: 3,
+            currency: 'EUR',
+        },
+    ];
+    expect(pricesForUsageOnTier(42, tiers, 'graduated')).toEqual({ EUR: 136 });
+    expect(pricesForUsageOnTier(42, tiers, 'volume')).toEqual({ EUR: 96 });
+});
+
+test('Test 3/21/2024 - with many free tiers and existing minimum', () => {
+    const tiers = [
+        {
+            threshold: 0,
+            price: 0,
+            currency: 'EUR',
+        },
+        {
+            threshold: 2,
+            price: 0,
+            currency: 'EUR',
+        },
+        {
+            threshold: 8,
+            price: 0,
+            currency: 'EUR',
+        },
+        {
+            threshold: 10,
+            price: 5,
+            currency: 'EUR',
+        },
+        {
+            threshold: 30,
+            price: 3,
+            currency: 'EUR',
+        },
+    ];
+    expect(pricesForUsageOnTier(42, tiers, 'graduated')).toEqual({ EUR: 136 });
+    expect(pricesForUsageOnTier(42, tiers, 'volume')).toEqual({ EUR: 96 });
 });