diff --git a/src/Airspace/index.ts b/src/Airspace/index.ts
index e655e81..4e40c40 100644
--- a/src/Airspace/index.ts
+++ b/src/Airspace/index.ts
@@ -1,9 +1,7 @@
-import path from 'path';
-import { getWSDLPath } from '../constants';
-import { getEndpoint } from '../config';
-import { prepareSecurity } from '../security';
 import { createClient } from 'soap';
 import { Config } from '../config';
+import { getWSDLPath } from '../constants';
+import { prepareSecurity } from '../security';
 import { deserializer as customDeserializer } from '../utils/transformers';
 
 export const getWSDL = ({
@@ -34,16 +32,17 @@ function createAirspaceServices(config: Config): Promise<AirspaceClient> {
 import queryCompleteAIXMDatasets, {
   Resolver as QueryCompleteAIXMDatasets,
 } from './queryCompleteAIXMDatasets';
+import retrieveAUP, { Resolver as RetrieveAUP } from './retrieveAUP';
 import retrieveAUPChain, {
   Resolver as RetrieveAUPChain,
 } from './retrieveAUPChain';
-import retrieveAUP, { Resolver as RetrieveAUP } from './retrieveAUP';
 import retrieveEAUPChain, {
   Resolver as RetrieveEAUPChain,
 } from './retrieveEAUPChain';
 
-export interface AirspaceService {
-  __soapClient: object;
+import { BaseServiceInterface } from '../Common/ServiceInterface';
+
+export interface AirspaceService extends BaseServiceInterface {
   queryCompleteAIXMDatasets: QueryCompleteAIXMDatasets;
   retrieveAUPChain: RetrieveAUPChain;
   retrieveEAUPChain: RetrieveEAUPChain;
@@ -53,6 +52,7 @@ export interface AirspaceService {
 export function getAirspaceClient(config: Config): Promise<AirspaceService> {
   return createAirspaceServices(config).then((client) => ({
     __soapClient: client,
+    config,
     queryCompleteAIXMDatasets: queryCompleteAIXMDatasets(client),
     retrieveAUPChain: retrieveAUPChain(client),
     retrieveEAUPChain: retrieveEAUPChain(client),
diff --git a/src/Common/ServiceInterface.ts b/src/Common/ServiceInterface.ts
new file mode 100644
index 0000000..1ae12f9
--- /dev/null
+++ b/src/Common/ServiceInterface.ts
@@ -0,0 +1,6 @@
+import type { Config } from '../config';
+
+export interface BaseServiceInterface {
+  __soapClient: object;
+  config: Config;
+}
diff --git a/src/Flight/index.ts b/src/Flight/index.ts
index a70a8d7..9176750 100644
--- a/src/Flight/index.ts
+++ b/src/Flight/index.ts
@@ -1,10 +1,7 @@
-import path from 'path';
-import { getWSDLPath } from '../constants';
-import { getEndpoint } from '../config';
-import { prepareSecurity } from '../security';
 import { createClient } from 'soap';
 import { Config } from '../config';
-import util from 'util';
+import { getWSDLPath } from '../constants';
+import { prepareSecurity } from '../security';
 import { deserializer as customDeserializer } from '../utils/transformers';
 
 const getWSDL = ({ flavour, XSD_PATH }: Pick<Config, 'flavour' | 'XSD_PATH'>) =>
@@ -38,32 +35,32 @@ function createFlightServices(config: Config): Promise<FlightClient> {
   });
 }
 
-import retrieveFlight from './retrieveFlight';
 import type { Resolver as RetrieveFlight } from './retrieveFlight';
+import retrieveFlight from './retrieveFlight';
 
-import queryFlightsByAirspace from './queryFlightsByAirspace';
 import type { Resolver as QueryFlightsByAirspace } from './queryFlightsByAirspace';
+import queryFlightsByAirspace from './queryFlightsByAirspace';
 
-import queryFlightPlans from './queryFlightPlans';
 import type { Resolver as QueryFlightPlans } from './queryFlightPlans';
+import queryFlightPlans from './queryFlightPlans';
 
-import queryFlightsByTrafficVolume from './queryFlightsByTrafficVolume';
 import type { Resolver as QueryFlightsByTrafficVolume } from './queryFlightsByTrafficVolume';
+import queryFlightsByTrafficVolume from './queryFlightsByTrafficVolume';
 
-import queryFlightsByMeasure from './queryFlightsByMeasure';
 import type { Resolver as QueryFlightsByMeasure } from './queryFlightsByMeasure';
+import queryFlightsByMeasure from './queryFlightsByMeasure';
 
-import queryFlightsByAerodrome from './queryFlightsByAerodrome';
 import type { Resolver as QueryFlightsByAerodrome } from './queryFlightsByAerodrome';
+import queryFlightsByAerodrome from './queryFlightsByAerodrome';
 
-import queryFlightsByAerodromeSet from './queryFlightsByAerodromeSet';
 import type { Resolver as QueryFlightsByAerodromeSet } from './queryFlightsByAerodromeSet';
+import queryFlightsByAerodromeSet from './queryFlightsByAerodromeSet';
 
-import queryFlightsByAircraftOperator from './queryFlightsByAircraftOperator';
+import { BaseServiceInterface } from '../Common/ServiceInterface';
 import type { Resolver as QueryFlightsByAircraftOperator } from './queryFlightsByAircraftOperator';
+import queryFlightsByAircraftOperator from './queryFlightsByAircraftOperator';
 
-export interface FlightService {
-  __soapClient: object;
+export interface FlightService extends BaseServiceInterface {
   retrieveFlight: RetrieveFlight;
   queryFlightsByAirspace: QueryFlightsByAirspace;
   queryFlightPlans: QueryFlightPlans;
@@ -77,6 +74,7 @@ export interface FlightService {
 export function getFlightClient(config: Config): Promise<FlightService> {
   return createFlightServices(config).then((client) => ({
     __soapClient: client,
+    config,
     retrieveFlight: retrieveFlight(client),
     queryFlightsByAirspace: queryFlightsByAirspace(client),
     queryFlightPlans: queryFlightPlans(client),
diff --git a/src/Flow/index.ts b/src/Flow/index.ts
index 3aa8f3f..bffdb6e 100644
--- a/src/Flow/index.ts
+++ b/src/Flow/index.ts
@@ -1,10 +1,7 @@
-import path from 'path';
-import { getWSDLPath } from '../constants';
-import { getEndpoint } from '../config';
-import { prepareSecurity } from '../security';
 import { createClient } from 'soap';
 import { Config } from '../config';
-import util from 'util';
+import { getWSDLPath } from '../constants';
+import { prepareSecurity } from '../security';
 import { deserializer as customDeserializer } from '../utils/transformers';
 
 const getWSDL = ({ flavour, XSD_PATH }: Pick<Config, 'flavour' | 'XSD_PATH'>) =>
@@ -38,31 +35,35 @@ function createFlowServices(config: Config): Promise<FlowClient> {
   });
 }
 
-import retrieveSectorConfigurationPlan from './retrieveSectorConfigurationPlan';
-import { Resolver as RetrieveSectorConfigurationPlan } from './retrieveSectorConfigurationPlan';
-import queryTrafficCountsByAirspace from './queryTrafficCountsByAirspace';
-import { Resolver as QueryTrafficCountsByAirspace } from './queryTrafficCountsByAirspace';
-import queryRegulations from './queryRegulations';
-import { Resolver as QueryRegulations } from './queryRegulations';
-import queryHotspots from './queryHotspots';
-import { Resolver as QueryHotspots } from './queryHotspots';
-import queryTrafficCountsByTrafficVolume from './queryTrafficCountsByTrafficVolume';
-import { Resolver as QueryTrafficCountsByTrafficVolume } from './queryTrafficCountsByTrafficVolume';
-import retrieveOTMVPlan from './retrieveOTMVPlan';
-import { Resolver as RetrieveOTMVPlan } from './retrieveOTMVPlan';
-import updateOTMVPlan from './updateOTMVPlan';
-import { Resolver as UpdateOTMVPlan } from './updateOTMVPlan';
+import { BaseServiceInterface } from '../Common/ServiceInterface';
+import queryHotspots, { Resolver as QueryHotspots } from './queryHotspots';
+import queryRegulations, {
+  Resolver as QueryRegulations,
+} from './queryRegulations';
+import queryTrafficCountsByAirspace, {
+  Resolver as QueryTrafficCountsByAirspace,
+} from './queryTrafficCountsByAirspace';
+import queryTrafficCountsByTrafficVolume, {
+  Resolver as QueryTrafficCountsByTrafficVolume,
+} from './queryTrafficCountsByTrafficVolume';
 import retrieveCapacityPlan, {
   Resolver as RetrieveCapacityPlan,
 } from './retrieveCapacityPlan';
-import updateCapacityPlan from './updateCapacityPlan';
-import { Resolver as UpdateCapacityPlan } from './updateCapacityPlan';
+import retrieveOTMVPlan, {
+  Resolver as RetrieveOTMVPlan,
+} from './retrieveOTMVPlan';
 import retrieveRunwayConfigurationPlan, {
   Resolver as RetrieveRunwayConfigurationPlan,
 } from './retrieveRunwayConfigurationPlan';
+import retrieveSectorConfigurationPlan, {
+  Resolver as RetrieveSectorConfigurationPlan,
+} from './retrieveSectorConfigurationPlan';
+import updateCapacityPlan, {
+  Resolver as UpdateCapacityPlan,
+} from './updateCapacityPlan';
+import updateOTMVPlan, { Resolver as UpdateOTMVPlan } from './updateOTMVPlan';
 
-export interface FlowService {
-  __soapClient: object;
+export interface FlowService extends BaseServiceInterface {
   retrieveSectorConfigurationPlan: RetrieveSectorConfigurationPlan;
   queryTrafficCountsByAirspace: QueryTrafficCountsByAirspace;
   queryRegulations: QueryRegulations;
@@ -78,6 +79,7 @@ export interface FlowService {
 export function getFlowClient(config: Config): Promise<FlowService> {
   return createFlowServices(config).then((client) => ({
     __soapClient: client,
+    config,
     retrieveSectorConfigurationPlan: retrieveSectorConfigurationPlan(client),
     queryTrafficCountsByAirspace: queryTrafficCountsByAirspace(client),
     queryRegulations: queryRegulations(client),
diff --git a/src/GeneralInformation/index.ts b/src/GeneralInformation/index.ts
index f42e582..3e208c1 100644
--- a/src/GeneralInformation/index.ts
+++ b/src/GeneralInformation/index.ts
@@ -1,9 +1,7 @@
+import { createClient } from 'soap';
+import { Config, getEndpoint } from '../config';
 import { getWSDLPath } from '../constants';
-import { getEndpoint } from '../config';
 import { prepareSecurity } from '../security';
-import { createClient } from 'soap';
-import { Config } from '../config';
-import util from 'util';
 import { deserializer as customDeserializer } from '../utils/transformers';
 
 const getWSDL = ({ flavour, XSD_PATH }: Pick<Config, 'flavour' | 'XSD_PATH'>) =>
@@ -36,12 +34,12 @@ function createGeneralInformationServices(
   });
 }
 
+import { BaseServiceInterface } from '../Common/ServiceInterface';
 import queryNMB2BWSDLs, {
   Resolver as QueryNMB2BWSDLs,
 } from './queryNMB2BWSDLs';
 
-export interface GeneralInformationService {
-  __soapClient: object;
+export interface GeneralInformationService extends BaseServiceInterface {
   queryNMB2BWSDLs: QueryNMB2BWSDLs;
 }
 
@@ -51,6 +49,7 @@ export function getGeneralInformationClient(
   return createGeneralInformationServices(config).then(
     (client) => ({
       __soapClient: client,
+      config,
       queryNMB2BWSDLs: queryNMB2BWSDLs(client),
     }),
     (err) => {
diff --git a/src/PublishSubscribe/index.ts b/src/PublishSubscribe/index.ts
index 0bbf125..fd24d58 100644
--- a/src/PublishSubscribe/index.ts
+++ b/src/PublishSubscribe/index.ts
@@ -1,9 +1,7 @@
-import path from 'path';
+import { createClient } from 'soap';
+import { Config, getEndpoint } from '../config';
 import { getWSDLPath } from '../constants';
-import { getEndpoint } from '../config';
 import { prepareSecurity } from '../security';
-import { createClient } from 'soap';
-import { Config } from '../config';
 import { deserializer as customDeserializer } from '../utils/transformers';
 
 const getWSDL = ({ flavour, XSD_PATH }: Pick<Config, 'flavour' | 'XSD_PATH'>) =>
@@ -30,19 +28,24 @@ function createPublishSubscribeServices(
   );
 }
 
-import listSubscriptions from './listSubscriptions';
-import { Resolver as ListSubscriptions } from './listSubscriptions';
-import createSubscription from './createSubscription';
-import { Resolver as CreateSubscription } from './createSubscription';
-import deleteSubscription from './deleteSubscription';
-import { Resolver as DeleteSubscription } from './deleteSubscription';
-import resumeSubscription from './resumeSubscription';
-import { Resolver as ResumeSubscription } from './resumeSubscription';
-import pauseSubscription from './pauseSubscription';
-import { Resolver as PauseSubscription } from './pauseSubscription';
+import createSubscription, {
+  Resolver as CreateSubscription,
+} from './createSubscription';
+import deleteSubscription, {
+  Resolver as DeleteSubscription,
+} from './deleteSubscription';
+import listSubscriptions, {
+  Resolver as ListSubscriptions,
+} from './listSubscriptions';
+import pauseSubscription, {
+  Resolver as PauseSubscription,
+} from './pauseSubscription';
+import resumeSubscription, {
+  Resolver as ResumeSubscription,
+} from './resumeSubscription';
+import { BaseServiceInterface } from '../Common/ServiceInterface';
 
-export interface PublishSubscribeService {
-  __soapClient: object;
+export interface PublishSubscribeService extends BaseServiceInterface {
   listSubscriptions: ListSubscriptions;
   createSubscription: CreateSubscription;
   deleteSubscription: DeleteSubscription;
@@ -53,8 +56,9 @@ export interface PublishSubscribeService {
 export function getPublishSubscribeClient(
   config: Config,
 ): Promise<PublishSubscribeService> {
-  return createPublishSubscribeServices(config).then(client => ({
+  return createPublishSubscribeServices(config).then((client) => ({
     __soapClient: client,
+    config,
     listSubscriptions: listSubscriptions(client),
     createSubscription: createSubscription(client),
     deleteSubscription: deleteSubscription(client),
diff --git a/src/index.test.ts b/src/index.test.ts
index 2fcdf3a..3fb14ed 100644
--- a/src/index.test.ts
+++ b/src/index.test.ts
@@ -12,8 +12,6 @@ import { Config } from './config';
 
 import { describe, test, expect } from 'vitest';
 
-// jest.setTimeout(20000);
-
 describe('Main API', () => {
   test('makeB2BClient', async () => {
     const b2bClient = await makeB2BClient(b2bOptions as Config);
@@ -34,5 +32,6 @@ describe('Main API', () => {
   ])('%O', async (fn) => {
     const res = await fn(b2bOptions);
     expect(res).toBeDefined();
+    expect(res.config).toEqual(b2bOptions);
   });
 });