diff --git a/src/lib/customers.ts b/src/lib/customers.ts
index 8a67406..b707bdd 100644
--- a/src/lib/customers.ts
+++ b/src/lib/customers.ts
@@ -3,7 +3,7 @@ import { query } from '../utils/PostgresConnection'
 import { pg as sql } from 'yesql'
 import { getConfig } from '../utils/config'
 import { stripe } from '../utils/StripeClientManager'
-import { constructUpsertSql } from '../utils/helpers'
+import { cleanseArrayField, constructUpsertSql } from '../utils/helpers'
 import { customerSchema } from '../schemas/customer'
 
 const config = getConfig()
@@ -13,7 +13,8 @@ export const upsertCustomer = async (customer: Customer.Customer): Promise<Custo
   const upsertString = constructUpsertSql(config.SCHEMA || 'stripe', 'customers', customerSchema)
 
   // Inject the values
-  const prepared = sql(upsertString)(customer)
+  const cleansed = cleanseArrayField(customer)
+  const prepared = sql(upsertString)(cleansed)
 
   // Run it
   const { rows } = await query(prepared.text, prepared.values)
diff --git a/src/lib/invoices.ts b/src/lib/invoices.ts
index 5d716d7..8360f30 100644
--- a/src/lib/invoices.ts
+++ b/src/lib/invoices.ts
@@ -3,7 +3,7 @@ import { query } from '../utils/PostgresConnection'
 import { pg as sql } from 'yesql'
 import { getConfig } from '../utils/config'
 import { stripe } from '../utils/StripeClientManager'
-import { constructUpsertSql } from '../utils/helpers'
+import { cleanseArrayField, constructUpsertSql } from '../utils/helpers'
 import { invoiceSchema } from '../schemas/invoice'
 import { verifyCustomerExists, fetchAndInsertCustomer } from './customers'
 import { verifySubscriptionExists, fetchAndInsertSubscription } from './subscriptions'
@@ -23,25 +23,12 @@ export const upsertInvoice = async (invoice: Invoice.Invoice): Promise<Invoice.I
     await fetchAndInsertSubscription(subscriptionId)
   }
 
-  /**
-   * For array object field like invoice.custom_fields
-   * ex: [{"name":"Project name","value":"Test Project"}]
-   *
-   * we need to stringify it first cos passing array object directly will end up with
-   * {
-   * invalid input syntax for type json
-   * detail: 'Expected ":", but found "}".',
-   * where: 'JSON data, line 1: ...\\":\\"Project name\\",\\"value\\":\\"Test Project\\"}"}',
-   * }
-   */
-  const customFields = invoice.custom_fields
-  const modifiedInvoice = { ...invoice, custom_fields: JSON.stringify(customFields) }
-
   // Create the SQL
   const upsertString = constructUpsertSql(config.SCHEMA || 'stripe', 'invoices', invoiceSchema)
 
   // Inject the values
-  const prepared = sql(upsertString)(modifiedInvoice)
+  const cleansed = cleanseArrayField(invoice)
+  const prepared = sql(upsertString)(cleansed)
 
   // Run it
   const { rows } = await query(prepared.text, prepared.values)
diff --git a/src/lib/prices.ts b/src/lib/prices.ts
index e7fdcb7..974e861 100644
--- a/src/lib/prices.ts
+++ b/src/lib/prices.ts
@@ -4,7 +4,7 @@ import { pg as sql } from 'yesql'
 import { getConfig } from '../utils/config'
 import { stripe } from '../utils/StripeClientManager'
 import { verifyProductExists, fetchAndInsertProduct } from './products'
-import { constructUpsertSql } from '../utils/helpers'
+import { cleanseArrayField, constructUpsertSql } from '../utils/helpers'
 import { priceSchema } from '../schemas/price'
 
 const config = getConfig()
@@ -20,7 +20,8 @@ export const upsertPrice = async (price: Price.Price): Promise<Price.Price[]> =>
   const upsertString = constructUpsertSql(config.SCHEMA || 'stripe', 'prices', priceSchema)
 
   // Inject the values
-  const prepared = sql(upsertString)(price)
+  const cleansed = cleanseArrayField(price)
+  const prepared = sql(upsertString)(cleansed)
 
   // Run it
   const { rows } = await query(prepared.text, prepared.values)
diff --git a/src/lib/products.ts b/src/lib/products.ts
index bddc45e..f06dcdd 100644
--- a/src/lib/products.ts
+++ b/src/lib/products.ts
@@ -4,7 +4,7 @@ import { pg as sql } from 'yesql'
 import { getConfig } from '../utils/config'
 import { stripe } from '../utils/StripeClientManager'
 import { productSchema } from '../schemas/product'
-import { constructUpsertSql } from '../utils/helpers'
+import { cleanseArrayField, constructUpsertSql } from '../utils/helpers'
 
 const config = getConfig()
 
@@ -13,7 +13,8 @@ export const upsertProduct = async (product: Product.Product): Promise<Product.P
   const upsertString = constructUpsertSql(config.SCHEMA || 'stripe', 'products', productSchema)
 
   // Inject the values
-  const prepared = sql(upsertString)(product)
+  const cleansed = cleanseArrayField(product)
+  const prepared = sql(upsertString)(cleansed)
 
   // Run it
   const { rows } = await query(prepared.text, prepared.values)
diff --git a/src/lib/subscription_items.ts b/src/lib/subscription_items.ts
index 7425230..7493c2f 100644
--- a/src/lib/subscription_items.ts
+++ b/src/lib/subscription_items.ts
@@ -3,7 +3,7 @@ import { query } from '../utils/PostgresConnection'
 import { pg as sql } from 'yesql'
 import { getConfig } from '../utils/config'
 import { stripe } from '../utils/StripeClientManager'
-import { constructUpsertSql } from '../utils/helpers'
+import { cleanseArrayField, constructUpsertSql } from '../utils/helpers'
 import { subscriptionItemSchema } from '../schemas/subscription_item'
 
 const config = getConfig()
@@ -29,7 +29,8 @@ export const upsertSubscriptionItem = async (
   )
 
   // Inject the values
-  const prepared = sql(upsertString)(modifiedSubscriptionItem)
+  const cleansed = cleanseArrayField(modifiedSubscriptionItem)
+  const prepared = sql(upsertString)(cleansed)
 
   // Run it
   const { rows } = await query(prepared.text, prepared.values)
diff --git a/src/lib/subscriptions.ts b/src/lib/subscriptions.ts
index 6c8f03d..8914007 100644
--- a/src/lib/subscriptions.ts
+++ b/src/lib/subscriptions.ts
@@ -3,7 +3,7 @@ import { query } from '../utils/PostgresConnection'
 import { pg as sql } from 'yesql'
 import { getConfig } from '../utils/config'
 import { stripe } from '../utils/StripeClientManager'
-import { constructUpsertSql } from '../utils/helpers'
+import { cleanseArrayField, constructUpsertSql } from '../utils/helpers'
 import { subscriptionSchema } from '../schemas/subscription'
 import { verifyCustomerExists, fetchAndInsertCustomer } from './customers'
 import { upsertSubscriptionItem } from './subscription_items'
@@ -27,7 +27,8 @@ export const upsertSubscription = async (
   )
 
   // Inject the values
-  const prepared = sql(upsertString)(subscription)
+  const cleansed = cleanseArrayField(subscription)
+  const prepared = sql(upsertString)(cleansed)
 
   // Run it
   const { rows } = await query(prepared.text, prepared.values)
diff --git a/src/utils/helpers.ts b/src/utils/helpers.ts
index 0508a4c..c45441b 100644
--- a/src/utils/helpers.ts
+++ b/src/utils/helpers.ts
@@ -41,3 +41,29 @@ export const constructUpsertSql = (
         .join(',')}
     ;`
 }
+
+/**
+ * For array object field like invoice.custom_fields
+ * ex: [{"name":"Project name","value":"Test Project"}]
+ *
+ * we need to stringify it first cos passing array object directly will end up with
+ * {
+ * invalid input syntax for type json
+ * detail: 'Expected ":", but found "}".',
+ * where: 'JSON data, line 1: ...\\":\\"Project name\\",\\"value\\":\\"Test Project\\"}"}',
+ * }
+ */
+export const cleanseArrayField = (obj: {
+  [Key: string]: any
+}): {
+  [Key: string]: any
+} => {
+  const cleansed = { ...obj }
+  Object.keys(cleansed).map((k) => {
+    const data = cleansed[k]
+    if (Array.isArray(data)) {
+      cleansed[k] = JSON.stringify(data)
+    }
+  })
+  return cleansed
+}