diff --git a/modules/pubmaticBidAdapter.js b/modules/pubmaticBidAdapter.js
index 6891285fcc22..c791acd94852 100644
--- a/modules/pubmaticBidAdapter.js
+++ b/modules/pubmaticBidAdapter.js
@@ -511,7 +511,7 @@ function _createImpressionObject(bid, conf) {
 
   impObj = {
     id: bid.bidId,
-    tagid: bid.params.adUnit,
+    tagid: bid.params.adUnit || undefined,
     bidfloor: _parseSlotParam('kadfloor', bid.params.kadfloor),
     secure: window.location.protocol === 'https:' ? 1 : 0,
     ext: {
@@ -746,10 +746,6 @@ export const spec = {
         utils.logWarn(LOG_WARN_PREFIX + 'Error: publisherId is mandatory and cannot be numeric. Call to OpenBid will not be sent for ad unit: ' + JSON.stringify(bid));
         return false;
       }
-      if (!utils.isStr(bid.params.adSlot)) {
-        utils.logWarn(LOG_WARN_PREFIX + 'Error: adSlotId is mandatory and cannot be numeric. Call to OpenBid will not be sent for ad unit: ' + JSON.stringify(bid));
-        return false;
-      }
       // video ad validation
       if (bid.params.hasOwnProperty('video')) {
         if (!bid.params.video.hasOwnProperty('mimes') || !utils.isArray(bid.params.video.mimes) || bid.params.video.mimes.length === 0) {
@@ -783,17 +779,11 @@ export const spec = {
     var blockedIabCategories = [];
     validBidRequests.forEach(originalBid => {
       bid = utils.deepClone(originalBid);
+      bid.params.adSlot = bid.params.adSlot || '';
       _parseAdSlot(bid);
       if (bid.params.hasOwnProperty('video')) {
-        if (!(bid.params.adSlot && bid.params.adUnit && bid.params.adUnitIndex)) {
-          utils.logWarn(LOG_WARN_PREFIX + 'Skipping the non-standard adslot: ', bid.params.adSlot, JSON.stringify(bid));
-          return;
-        }
+        // Nothing to do
       } else {
-        if (!(bid.params.adSlot && bid.params.adUnit && bid.params.adUnitIndex)) {
-          utils.logWarn(LOG_WARN_PREFIX + 'Skipping the non-standard adslot: ', bid.params.adSlot, JSON.stringify(bid));
-          return;
-        }
         // If we have a native mediaType configured alongside banner, its ok if the banner size is not set in width and height
         // The corresponding banner imp object will not be generated, but we still want the native object to be sent, hence the following check
         if (!(bid.hasOwnProperty('mediaTypes') && bid.mediaTypes.hasOwnProperty(NATIVE)) && bid.params.width === 0 && bid.params.height === 0) {
diff --git a/modules/pubmaticBidAdapter.md b/modules/pubmaticBidAdapter.md
index 16a3b203e202..1948acba40fa 100644
--- a/modules/pubmaticBidAdapter.md
+++ b/modules/pubmaticBidAdapter.md
@@ -25,7 +25,7 @@ var adUnits = [
       bidder: 'pubmatic',
       params: {
         publisherId: '156209',               // required
-        adSlot: 'pubmatic_test2',            // required
+        adSlot: 'pubmatic_test2',            // optional
         pmzoneid: 'zone1, zone11',           // optional
         lat: '40.712775',                    // optional
         lon: '-74.005973',                   // optional
@@ -56,7 +56,7 @@ var adVideoAdUnits = [
       bidder: 'pubmatic',
       params: {
         publisherId: '156209',                  // required
-        adSlot: 'pubmatic_video1',              // required
+        adSlot: 'pubmatic_video1',              // optional
         video: {
           mimes: ['video/mp4','video/x-flv'],   // required
           skippable: true,                      // optional
@@ -104,7 +104,7 @@ var adUnits = [
       bidder: 'pubmatic',
       params: {
         publisherId: '156295',               // required
-        adSlot: 'pubmatic_test2@1x1',       // required
+        adSlot: 'pubmatic_test2@1x1',       // optional
       }
     }]
 }];
@@ -146,7 +146,7 @@ var adUnits = [
       bidder: 'pubmatic',
       params: {
         publisherId: '156209',               // required
-        adSlot: 'pubmatic_test2@300x250',    // required
+        adSlot: 'pubmatic_test2@300x250',    // optional
         pmzoneid: 'zone1, zone11',           // optional
         lat: '40.712775',                    // optional
         lon: '-74.005973',                   // optional
diff --git a/test/spec/modules/pubmaticBidAdapter_spec.js b/test/spec/modules/pubmaticBidAdapter_spec.js
index bf008574027e..b25fd22f822f 100644
--- a/test/spec/modules/pubmaticBidAdapter_spec.js
+++ b/test/spec/modules/pubmaticBidAdapter_spec.js
@@ -668,27 +668,15 @@ describe('PubMatic adapter', function () {
         expect(isValid).to.equal(false);
       });
 
-  		it('invalid bid case: adSlot not passed', function () {
-  		  let validBid = {
-	        bidder: 'pubmatic',
-	        params: {
-	          publisherId: '301'
-	        }
-	      },
-	      isValid = spec.isBidRequestValid(validBid);
-	      expect(isValid).to.equal(false);
-    	});
-
-      it('invalid bid case: adSlot is not string', function () {
+      it('valid bid case: adSlot is not passed', function () {
         let validBid = {
             bidder: 'pubmatic',
             params: {
-              publisherId: '301',
-              adSlot: 15671365
+              publisherId: '301'
             }
           },
           isValid = spec.isBidRequestValid(validBid);
-        expect(isValid).to.equal(false);
+        expect(isValid).to.equal(true);
       });
     });
 
@@ -742,6 +730,39 @@ describe('PubMatic adapter', function () {
         expect(data.imp[0].bidfloorcur).to.equal(bidRequests[0].params.currency);
   		});
 
+      it('Request params check: without adSlot', function () {
+        delete bidRequests[0].params.adSlot;
+        let request = spec.buildRequests(bidRequests);
+        let data = JSON.parse(request.data);
+        expect(data.at).to.equal(1); // auction type
+        expect(data.cur[0]).to.equal('USD'); // currency
+        expect(data.site.domain).to.be.a('string'); // domain should be set
+        expect(data.site.page).to.equal(bidRequests[0].params.kadpageurl); // forced pageURL
+        expect(data.site.publisher.id).to.equal(bidRequests[0].params.publisherId); // publisher Id
+        expect(data.site.ext).to.exist.and.to.be.an('object'); // dctr parameter
+        expect(data.site.ext.key_val).to.exist.and.to.equal(bidRequests[0].params.dctr);
+        expect(data.user.yob).to.equal(parseInt(bidRequests[0].params.yob)); // YOB
+        expect(data.user.gender).to.equal(bidRequests[0].params.gender); // Gender
+        expect(data.device.geo.lat).to.equal(parseFloat(bidRequests[0].params.lat)); // Latitude
+        expect(data.device.geo.lon).to.equal(parseFloat(bidRequests[0].params.lon)); // Lognitude
+        expect(data.user.geo.lat).to.equal(parseFloat(bidRequests[0].params.lat)); // Latitude
+        expect(data.user.geo.lon).to.equal(parseFloat(bidRequests[0].params.lon)); // Lognitude
+        expect(data.ext.wrapper.wv).to.equal($$REPO_AND_VERSION$$); // Wrapper Version
+        expect(data.ext.wrapper.transactionId).to.equal(bidRequests[0].transactionId); // Prebid TransactionId
+        expect(data.ext.wrapper.wiid).to.equal(bidRequests[0].params.wiid); // OpenWrap: Wrapper Impression ID
+        expect(data.ext.wrapper.profile).to.equal(parseInt(bidRequests[0].params.profId)); // OpenWrap: Wrapper Profile ID
+        expect(data.ext.wrapper.version).to.equal(parseInt(bidRequests[0].params.verId)); // OpenWrap: Wrapper Profile Version ID
+
+        expect(data.imp[0].id).to.equal(bidRequests[0].bidId); // Prebid bid id is passed as id
+        expect(data.imp[0].bidfloor).to.equal(parseFloat(bidRequests[0].params.kadfloor)); // kadfloor
+        expect(data.imp[0].tagid).to.deep.equal(undefined); // tagid
+        expect(data.imp[0].banner.w).to.equal(728); // width
+        expect(data.imp[0].banner.h).to.equal(90); // height
+        expect(data.imp[0].banner.format).to.deep.equal([{w: 160, h: 600}]);
+        expect(data.imp[0].ext.pmZoneId).to.equal(bidRequests[0].params.pmzoneid.split(',').slice(0, 50).map(id => id.trim()).join()); // pmzoneid
+        expect(data.imp[0].bidfloorcur).to.equal(bidRequests[0].params.currency);
+      });
+
       it('Request params multi size format object check', function () {
         let bidRequests = [
           {