diff --git a/backend/src/graphql/arg/AdminCreateContributionArgs.ts b/backend/src/graphql/arg/AdminCreateContributionArgs.ts
index 1c6007c48..558821921 100644
--- a/backend/src/graphql/arg/AdminCreateContributionArgs.ts
+++ b/backend/src/graphql/arg/AdminCreateContributionArgs.ts
@@ -3,6 +3,7 @@ import { Decimal } from 'decimal.js-light'
 import { ArgsType, Field, InputType } from 'type-graphql'
 
 import { MEMO_MAX_CHARS, MEMO_MIN_CHARS } from '@/graphql/resolver/const/const'
+import { IsPositiveDecimal } from '@/graphql/validator/Decimal'
 
 @InputType()
 @ArgsType()
@@ -11,6 +12,7 @@ export class AdminCreateContributionArgs {
   email: string
 
   @Field(() => Decimal)
+  @IsPositiveDecimal()
   amount: Decimal
 
   @Field(() => String)
diff --git a/backend/src/graphql/arg/AdminUpdateContributionArgs.ts b/backend/src/graphql/arg/AdminUpdateContributionArgs.ts
index 4958b4346..c5f560c9a 100644
--- a/backend/src/graphql/arg/AdminUpdateContributionArgs.ts
+++ b/backend/src/graphql/arg/AdminUpdateContributionArgs.ts
@@ -3,6 +3,7 @@ import { Decimal } from 'decimal.js-light'
 import { ArgsType, Field, Int } from 'type-graphql'
 
 import { MEMO_MAX_CHARS, MEMO_MIN_CHARS } from '@/graphql/resolver/const/const'
+import { IsPositiveDecimal } from '@/graphql/validator/Decimal'
 
 @ArgsType()
 export class AdminUpdateContributionArgs {
@@ -10,6 +11,7 @@ export class AdminUpdateContributionArgs {
   id: number
 
   @Field(() => Decimal)
+  @IsPositiveDecimal()
   amount: Decimal
 
   @Field(() => String)
diff --git a/backend/src/graphql/arg/ContributionArgs.ts b/backend/src/graphql/arg/ContributionArgs.ts
index e2449ea95..d4c9e639b 100644
--- a/backend/src/graphql/arg/ContributionArgs.ts
+++ b/backend/src/graphql/arg/ContributionArgs.ts
@@ -3,11 +3,13 @@ import { Decimal } from 'decimal.js-light'
 import { ArgsType, Field, InputType } from 'type-graphql'
 
 import { MEMO_MAX_CHARS, MEMO_MIN_CHARS } from '@/graphql/resolver/const/const'
+import { IsPositiveDecimal } from '@/graphql/validator/Decimal'
 
 @InputType()
 @ArgsType()
 export class ContributionArgs {
   @Field(() => Decimal)
+  @IsPositiveDecimal()
   amount: Decimal
 
   @Field(() => String)
diff --git a/backend/src/graphql/arg/ContributionLinkArgs.ts b/backend/src/graphql/arg/ContributionLinkArgs.ts
index 59688a969..4aa268d28 100644
--- a/backend/src/graphql/arg/ContributionLinkArgs.ts
+++ b/backend/src/graphql/arg/ContributionLinkArgs.ts
@@ -8,10 +8,12 @@ import {
   CONTRIBUTIONLINK_NAME_MIN_CHARS,
   CONTRIBUTIONLINK_NAME_MAX_CHARS,
 } from '@/graphql/resolver/const/const'
+import { IsPositiveDecimal } from '@/graphql/validator/Decimal'
 
 @ArgsType()
 export class ContributionLinkArgs {
   @Field(() => Decimal)
+  @IsPositiveDecimal()
   amount: Decimal
 
   @Field(() => String)
diff --git a/backend/src/graphql/arg/TransactionLinkArgs.ts b/backend/src/graphql/arg/TransactionLinkArgs.ts
index 2ffd91d33..6dfdda15e 100644
--- a/backend/src/graphql/arg/TransactionLinkArgs.ts
+++ b/backend/src/graphql/arg/TransactionLinkArgs.ts
@@ -1,12 +1,14 @@
-import { MaxLength, MinLength } from 'class-validator'
+import { IsAlpha, MaxLength, MinLength } from 'class-validator'
 import { Decimal } from 'decimal.js-light'
 import { ArgsType, Field } from 'type-graphql'
 
 import { MEMO_MAX_CHARS, MEMO_MIN_CHARS } from '@/graphql/resolver/const/const'
+import { IsPositiveDecimal } from '@/graphql/validator/Decimal'
 
 @ArgsType()
 export class TransactionLinkArgs {
   @Field(() => Decimal)
+  @IsPositiveDecimal()
   amount: Decimal
 
   @Field(() => String)
diff --git a/backend/src/graphql/arg/TransactionSendArgs.ts b/backend/src/graphql/arg/TransactionSendArgs.ts
index 1279f2051..d8a556b99 100644
--- a/backend/src/graphql/arg/TransactionSendArgs.ts
+++ b/backend/src/graphql/arg/TransactionSendArgs.ts
@@ -3,6 +3,7 @@ import { Decimal } from 'decimal.js-light'
 import { ArgsType, Field } from 'type-graphql'
 
 import { MEMO_MAX_CHARS, MEMO_MIN_CHARS } from '@/graphql/resolver/const/const'
+import { IsPositiveDecimal } from '@/graphql/validator/Decimal'
 
 @ArgsType()
 export class TransactionSendArgs {
@@ -10,6 +11,7 @@ export class TransactionSendArgs {
   identifier: string
 
   @Field(() => Decimal)
+  @IsPositiveDecimal()
   amount: Decimal
 
   @Field(() => String)
diff --git a/backend/src/graphql/resolver/ContributionLinkResolver.ts b/backend/src/graphql/resolver/ContributionLinkResolver.ts
index e8a694a55..1f9e5ce26 100644
--- a/backend/src/graphql/resolver/ContributionLinkResolver.ts
+++ b/backend/src/graphql/resolver/ContributionLinkResolver.ts
@@ -41,10 +41,6 @@ export class ContributionLinkResolver {
   ): Promise<ContributionLink> {
     isStartEndDateValid(validFrom, validTo)
 
-    if (!new Decimal(amount).isPositive()) {
-      throw new LogError('The amount must be a positiv value', amount)
-    }
-
     const dbContributionLink = new DbContributionLink()
     dbContributionLink.amount = amount
     dbContributionLink.name = name
diff --git a/backend/src/graphql/resolver/TransactionLinkResolver.ts b/backend/src/graphql/resolver/TransactionLinkResolver.ts
index 282e6662a..cc0484588 100644
--- a/backend/src/graphql/resolver/TransactionLinkResolver.ts
+++ b/backend/src/graphql/resolver/TransactionLinkResolver.ts
@@ -73,10 +73,6 @@ export class TransactionLinkResolver {
     const createdDate = new Date()
     const validUntil = transactionLinkExpireDate(createdDate)
 
-    if (amount.lessThanOrEqualTo(0)) {
-      throw new LogError('Amount must be a positive number', amount)
-    }
-
     const holdAvailableAmount = amount.minus(calculateDecay(amount, createdDate, validUntil).decay)
 
     // validate amount
diff --git a/backend/src/graphql/resolver/TransactionResolver.ts b/backend/src/graphql/resolver/TransactionResolver.ts
index 721cba8fa..525be81fa 100644
--- a/backend/src/graphql/resolver/TransactionResolver.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.ts
@@ -308,9 +308,6 @@ export class TransactionResolver {
     @Ctx() context: Context,
   ): Promise<boolean> {
     logger.info(`sendCoins(identifier=${identifier}, amount=${amount}, memo=${memo})`)
-    if (amount.lte(0)) {
-      throw new LogError('Amount to send must be positive', amount)
-    }
 
     const senderUser = getUser(context)
 
diff --git a/backend/src/graphql/validator/Decimal.ts b/backend/src/graphql/validator/Decimal.ts
new file mode 100644
index 000000000..caf13143d
--- /dev/null
+++ b/backend/src/graphql/validator/Decimal.ts
@@ -0,0 +1,22 @@
+import { registerDecorator, ValidationOptions, ValidationArguments } from 'class-validator'
+import { Decimal } from 'decimal.js-light'
+
+export function IsPositiveDecimal(validationOptions?: ValidationOptions) {
+  return function (object: NonNullable<unknown>, propertyName: string) {
+    registerDecorator({
+      name: 'isPositiveDecimal',
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+      target: object.constructor,
+      propertyName,
+      options: validationOptions,
+      validator: {
+        validate(value: Decimal) {
+          return value.greaterThan(0)
+        },
+        defaultMessage(args: ValidationArguments) {
+          return `The ${propertyName} must be a positive value ${args.property}`
+        },
+      },
+    })
+  }
+}