diff --git a/src/international_street/Client.js b/src/international_street/Client.js
index ef0a322..727aa64 100644
--- a/src/international_street/Client.js
+++ b/src/international_street/Client.js
@@ -16,6 +16,8 @@ class Client {
 	send(lookup) {
 		if (typeof lookup === "undefined") throw new Errors.UndefinedLookupError();
 
+		lookup.ensureEnoughInfo();
+
 		let request = new Request();
 		request.parameters = buildInputData(lookup, keyTranslationFormat);
 
diff --git a/src/international_street/Lookup.js b/src/international_street/Lookup.js
index 4357ccb..00b2a5c 100644
--- a/src/international_street/Lookup.js
+++ b/src/international_street/Lookup.js
@@ -2,7 +2,6 @@ const UnprocessableEntityError = require("../Errors").UnprocessableEntityError;
 const messages = {
 	countryRequired: "Country field is required.",
 	freeformOrAddress1Required: "Either freeform or address1 is required.",
-	insufficientInformation: "Insufficient information: One or more required fields were not set on the lookup.",
 	badGeocode: "Invalid input: geocode can only be set to 'true' (default is 'false'.",
 	invalidLanguage: "Invalid input: language can only be set to 'latin' or 'native'. When not set, the the output language will match the language of the input values."
 };
@@ -45,13 +44,7 @@ class Lookup {
 	ensureEnoughInfo() {
 		if (fieldIsMissing(this.country)) throw new UnprocessableEntityError(messages.countryRequired);
 
-		if (fieldIsSet(this.freeform)) return true;
-
-		if (fieldIsMissing(this.address1)) throw new UnprocessableEntityError(messages.freeformOrAddress1Required);
-
-		if (fieldIsSet(this.postalCode)) return true;
-
-		if (fieldIsMissing(this.locality) || fieldIsMissing(this.administrativeArea)) throw new UnprocessableEntityError(messages.insufficientInformation);
+		if (fieldIsMissing(this.freeform) && fieldIsMissing(this.address1)) throw new UnprocessableEntityError(messages.freeformOrAddress1Required);
 
 		return true;
 	}
diff --git a/tests/international_street/test_Client.js b/tests/international_street/test_Client.js
index 20e64e7..6224e5f 100644
--- a/tests/international_street/test_Client.js
+++ b/tests/international_street/test_Client.js
@@ -22,6 +22,20 @@ describe("An International Street client", function () {
 		expect(client.send).to.throw(errors.UndefinedLookupError);
 	});
 
+	it("throws an error if sending an empty lookup.", function () {
+		let mockSender = new MockSender();
+		let client = new Client(mockSender);
+
+		expect(() => client.send(new Lookup())).to.throw(errors.UnprocessableEntityError, "Country field is required.");
+	});
+
+	it("throws an error if sending a lookup with country but missing freeform and address1.", function () {
+		let mockSender = new MockSender();
+		let client = new Client(mockSender);
+
+		expect(() => client.send(new Lookup("CA"))).to.throw(errors.UnprocessableEntityError, "Either freeform or address1 is required.");
+	});
+
 	it("correctly assigns request parameters based on lookup input.", function () {
 		let mockSender = new MockSender();
 		let client = new Client(mockSender);
@@ -60,7 +74,7 @@ describe("An International Street client", function () {
 		const expectedMockPayload = [{address1: "A", }];
 		let mockSender = new MockSenderWithResponse(expectedMockPayload);
 		const client = new Client(mockSender);
-		let lookup = new Lookup();
+		let lookup = new Lookup("CA", "123 Main St");
 		let expectedResult = new Candidate({address1: "A"});
 
 		return client.send(lookup).then(response => {
diff --git a/tests/international_street/test_Lookup.js b/tests/international_street/test_Lookup.js
index ed4e40f..c2c9e91 100644
--- a/tests/international_street/test_Lookup.js
+++ b/tests/international_street/test_Lookup.js
@@ -7,7 +7,6 @@ describe("An International Street lookup", function () {
 	const messages = {
 		countryRequired: "Country field is required.",
 		freeformOrAddress1Required: "Either freeform or address1 is required.",
-		insufficientInformation: "Insufficient information: One or more required fields were not set on the lookup.",
 		badGeocode: "Invalid input: geocode can only be set to 'true' (default is 'false'.",
 		invalidLanguage: "Invalid input: language can only be set to 'latin' or 'native'. When not set, the the output language will match the language of the input values."
 	};
@@ -27,29 +26,6 @@ describe("An International Street lookup", function () {
 		ensureValidationThrows(new Lookup("a").ensureEnoughInfo, messages.freeformOrAddress1Required);
 	});
 
-	it("rejects lookups with only a country and address 1.", function () {
-		let lookup = new Lookup("a");
-		lookup.address1 = "b";
-
-		ensureValidationThrows(lookup.ensureEnoughInfo, messages.insufficientInformation);
-	});
-
-	it("rejects lookups with only a country, address 1, and locality.", function () {
-		let lookup = new Lookup("a");
-		lookup.address1 = "b";
-		lookup.locality = "c";
-
-		ensureValidationThrows(lookup.ensureEnoughInfo, messages.insufficientInformation);
-	});
-
-	it("rejects lookups with only a country, address 1, and adminstrative area.", function () {
-		let lookup = new Lookup("a");
-		lookup.address1 = "b";
-		lookup.administrativeArea = "c";
-
-		ensureValidationThrows(lookup.ensureEnoughInfo, messages.insufficientInformation);
-	});
-
 	it("rejects lookups with an invalid geocode value.", function () {
 		let lookup = new Lookup();
 		lookup.geocode = "Blarg!";
@@ -69,16 +45,9 @@ describe("An International Street lookup", function () {
 
 		let lookup2 = new Lookup("a");
 		lookup2.address1 = "b";
-		lookup2.postalCode = "c";
-
-		let lookup3 = new Lookup("a");
-		lookup3.address1 = "b";
-		lookup3.locality = "c";
-		lookup3.administrativeArea = "d";
 
 		expect(lookup1.ensureEnoughInfo()).to.equal(true);
 		expect(lookup2.ensureEnoughInfo()).to.equal(true);
-		expect(lookup3.ensureEnoughInfo()).to.equal(true);
 	});
 
 	it("accepts lookups with a valid language.", function () {