diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c3238507a..12891851a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -528,7 +528,7 @@ jobs:
           report_name: Coverage Backend
           type: lcov
           result_path: ./backend/coverage/lcov.info
-          min_coverage: 74
+          min_coverage: 77
           token: ${{ github.token }}
 
   ##########################################################################
diff --git a/backend/src/graphql/resolver/semaphore.test.ts b/backend/src/graphql/resolver/semaphore.test.ts
new file mode 100644
index 000000000..e334910f1
--- /dev/null
+++ b/backend/src/graphql/resolver/semaphore.test.ts
@@ -0,0 +1,190 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+
+import Decimal from 'decimal.js-light'
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+import { logger } from '@test/testSetup'
+import { userFactory } from '@/seeds/factory/user'
+import { bibiBloxberg } from '@/seeds/users/bibi-bloxberg'
+import { bobBaumeister } from '@/seeds/users/bob-baumeister'
+import { peterLustig } from '@/seeds/users/peter-lustig'
+import { creationFactory, nMonthsBefore } from '@/seeds/factory/creation'
+import { cleanDB, testEnvironment, contributionDateFormatter } from '@test/helpers'
+import {
+  confirmContribution,
+  createContribution,
+  createTransactionLink,
+  redeemTransactionLink,
+  login,
+  createContributionLink,
+  sendCoins,
+} from '@/seeds/graphql/mutations'
+
+let mutate: any, con: any
+let testEnv: any
+
+beforeAll(async () => {
+  testEnv = await testEnvironment()
+  mutate = testEnv.mutate
+  con = testEnv.con
+  await cleanDB()
+})
+
+afterAll(async () => {
+  await cleanDB()
+  await con.close()
+})
+
+describe('semaphore', () => {
+  let contributionLinkCode = ''
+  let bobsTransactionLinkCode = ''
+  let bibisTransactionLinkCode = ''
+  let bibisOpenContributionId = -1
+  let bobsOpenContributionId = -1
+
+  beforeAll(async () => {
+    const now = new Date()
+    await userFactory(testEnv, bibiBloxberg)
+    await userFactory(testEnv, peterLustig)
+    await userFactory(testEnv, bobBaumeister)
+    await creationFactory(testEnv, {
+      email: 'bibi@bloxberg.de',
+      amount: 1000,
+      memo: 'Herzlich Willkommen bei Gradido!',
+      creationDate: nMonthsBefore(new Date()),
+      confirmed: true,
+    })
+    await creationFactory(testEnv, {
+      email: 'bob@baumeister.de',
+      amount: 1000,
+      memo: 'Herzlich Willkommen bei Gradido!',
+      creationDate: nMonthsBefore(new Date()),
+      confirmed: true,
+    })
+    await mutate({
+      mutation: login,
+      variables: { email: 'peter@lustig.de', password: 'Aa12345_' },
+    })
+    const {
+      data: { createContributionLink: contributionLink },
+    } = await mutate({
+      mutation: createContributionLink,
+      variables: {
+        amount: new Decimal(200),
+        name: 'Test Contribution Link',
+        memo: 'Danke für deine Teilnahme an dem Test der Contribution Links',
+        cycle: 'ONCE',
+        validFrom: new Date(2022, 5, 18).toISOString(),
+        validTo: new Date(now.getFullYear() + 1, 7, 14).toISOString(),
+        maxAmountPerMonth: new Decimal(200),
+        maxPerCycle: 1,
+      },
+    })
+    contributionLinkCode = 'CL-' + contributionLink.code
+    await mutate({
+      mutation: login,
+      variables: { email: 'bob@baumeister.de', password: 'Aa12345_' },
+    })
+    const {
+      data: { createTransactionLink: bobsLink },
+    } = await mutate({
+      mutation: createTransactionLink,
+      variables: {
+        email: 'bob@baumeister.de',
+        amount: 20,
+        memo: 'Bobs Link',
+      },
+    })
+    const {
+      data: { createContribution: bobsContribution },
+    } = await mutate({
+      mutation: createContribution,
+      variables: {
+        creationDate: contributionDateFormatter(new Date()),
+        amount: 200,
+        memo: 'Bobs Contribution',
+      },
+    })
+    await mutate({
+      mutation: login,
+      variables: { email: 'bibi@bloxberg.de', password: 'Aa12345_' },
+    })
+    const {
+      data: { createTransactionLink: bibisLink },
+    } = await mutate({
+      mutation: createTransactionLink,
+      variables: {
+        amount: 20,
+        memo: 'Bibis Link',
+      },
+    })
+    const {
+      data: { createContribution: bibisContribution },
+    } = await mutate({
+      mutation: createContribution,
+      variables: {
+        creationDate: contributionDateFormatter(new Date()),
+        amount: 200,
+        memo: 'Bibis Contribution',
+      },
+    })
+    bobsTransactionLinkCode = bobsLink.code
+    bibisTransactionLinkCode = bibisLink.code
+    bibisOpenContributionId = bibisContribution.id
+    bobsOpenContributionId = bobsContribution.id
+  })
+
+  it('creates a lot of transactions without errors', async () => {
+    await mutate({
+      mutation: login,
+      variables: { email: 'bibi@bloxberg.de', password: 'Aa12345_' },
+    })
+    const bibiRedeemContributionLink = mutate({
+      mutation: redeemTransactionLink,
+      variables: { code: contributionLinkCode },
+    })
+    const redeemBobsLink = mutate({
+      mutation: redeemTransactionLink,
+      variables: { code: bobsTransactionLinkCode },
+    })
+    const bibisTransaction = mutate({
+      mutation: sendCoins,
+      variables: { email: 'bob@baumeister.de', amount: '50', memo: 'Das ist für dich, Bob' },
+    })
+    await mutate({
+      mutation: login,
+      variables: { email: 'bob@baumeister.de', password: 'Aa12345_' },
+    })
+    const bobRedeemContributionLink = mutate({
+      mutation: redeemTransactionLink,
+      variables: { code: contributionLinkCode },
+    })
+    const redeemBibisLink = mutate({
+      mutation: redeemTransactionLink,
+      variables: { code: bibisTransactionLinkCode },
+    })
+    const bobsTransaction = mutate({
+      mutation: sendCoins,
+      variables: { email: 'bibi@bloxberg.de', amount: '50', memo: 'Das ist für dich, Bibi' },
+    })
+    await mutate({
+      mutation: login,
+      variables: { email: 'peter@lustig.de', password: 'Aa12345_' },
+    })
+    const confirmBibisContribution = mutate({
+      mutation: confirmContribution,
+      variables: { id: bibisOpenContributionId },
+    })
+    const confirmBobsContribution = mutate({
+      mutation: confirmContribution,
+      variables: { id: bobsOpenContributionId },
+    })
+    await expect(bibiRedeemContributionLink).resolves.toMatchObject({ errors: undefined })
+    await expect(redeemBobsLink).resolves.toMatchObject({ errors: undefined })
+    await expect(bibisTransaction).resolves.toMatchObject({ errors: undefined })
+    await expect(bobRedeemContributionLink).resolves.toMatchObject({ errors: undefined })
+    await expect(redeemBibisLink).resolves.toMatchObject({ errors: undefined })
+    await expect(bobsTransaction).resolves.toMatchObject({ errors: undefined })
+    await expect(confirmBibisContribution).resolves.toMatchObject({ errors: undefined })
+    await expect(confirmBobsContribution).resolves.toMatchObject({ errors: undefined })
+  })
+})