diff --git a/packages/binding-coap/src/coap-server.ts b/packages/binding-coap/src/coap-server.ts
index b2bad7c1f..25b2ab3ab 100644
--- a/packages/binding-coap/src/coap-server.ts
+++ b/packages/binding-coap/src/coap-server.ts
@@ -333,14 +333,21 @@ export default class CoapServer implements ProtocolServer {
      *
      * @param req The incoming request.
      * @param res The outgoing response.
-     * @param thing The ExposedThing whose TD is requested.
+     * @param thingKey The key of the ExposedThing whose TD is requested.
      */
-    private async handleTdRequest(req: IncomingMessage, res: OutgoingMessage, thing: ExposedThing) {
+    private async handleTdRequest(req: IncomingMessage, res: OutgoingMessage, thingKey: string) {
         if (req.method !== "GET") {
             this.sendErrorResponse(res, "4.05", "Method Not Allowed");
             return;
         }
 
+        const thing = this.things.get(thingKey);
+
+        if (thing == null) {
+            this.sendErrorResponse(res, "4.04", "Not Found");
+            return;
+        }
+
         const accept = req.headers.Accept;
 
         const contentSerdes = ContentSerdes.get();
@@ -378,32 +385,18 @@ export default class CoapServer implements ProtocolServer {
             );
         });
 
-        let contentType;
+        const contentType = this.getContentTypeFromRequest(req);
 
-        try {
-            contentType = this.getContentTypeFromRequest(req);
-        } catch (exception) {
-            // FIXME
-            this.sendErrorResponse(res, "415", exception.msg);
+        if (!this.checkContentTypeSupportForInput(res, req.method, contentType)) {
+            this.sendErrorResponse(res, "4.15", "Unsupported Media Type");
             return;
         }
 
         const requestUri = this.processRequestUri(req);
-        const segments = decodeURI(requestUri).split("/");
+        const { thingKey, affordanceType, affordanceKey } = this.parseUriSegments(requestUri);
 
         if (requestUri === "/") {
-            // no path -> list all Things
-            if (req.method !== "GET") {
-                this.sendErrorResponse(res, "4.05", "Method Not Allowed");
-                return;
-            }
-
-            res.setHeader("Content-Format", ContentSerdes.DEFAULT);
-            res.code = "2.05";
-            const payload = JSON.stringify(this.getThingDescriptionPayload());
-            res.end(payload);
-
-            // resource found and response sent
+            this.handleThingsRequest(req, res);
             return;
         }
 
@@ -412,23 +405,11 @@ export default class CoapServer implements ProtocolServer {
             return;
         }
 
-        // path -> select Thing
-        const thing = this.things.get(segments[1]);
-
-        if (thing == null) {
-            this.sendErrorResponse(res, "4.04", "Not Found");
-            return;
-        }
-
-        const affordanceType = segments[2];
-        if (segments.length === 2 || affordanceType === "") {
-            // Thing root -> send TD
-            await this.handleTdRequest(req, res, thing);
+        if (affordanceType == null || affordanceType === "") {
+            await this.handleTdRequest(req, res, thingKey);
             return;
         }
 
-        const affordanceKey = segments[3];
-
         switch (affordanceType) {
             case this.PROPERTY_DIR:
                 this.handlePropertyRequest(thing, affordanceKey, req, res, contentType);
@@ -454,6 +435,18 @@ export default class CoapServer implements ProtocolServer {
         return uri;
     }
 
+    private handleThingsRequest(method: string, res: OutgoingMessage) {
+        if (method !== "GET") {
+            this.sendErrorResponse(res, "4.05", "Method Not Allowed");
+            return;
+        }
+
+        res.setHeader("Content-Format", ContentSerdes.DEFAULT);
+        res.code = "2.05";
+        const payload = JSON.stringify(this.getThingDescriptionPayload());
+        res.end(payload);
+    }
+
     private async handlePropertyRequest(
         thing: ExposedThing,
         affordanceKey: string,
@@ -596,6 +589,7 @@ export default class CoapServer implements ProtocolServer {
         const action = thing.actions[affordanceKey];
 
         if (action == null) {
+            this.sendErrorResponse(res, "4.04", "Not Found");
             return;
         }
 
@@ -638,10 +632,10 @@ export default class CoapServer implements ProtocolServer {
         res: OutgoingMessage,
         contentType?: string
     ) {
-        // sub-path -> select Event
         const event = thing.events[affordanceKey];
 
         if (event == null) {
+            this.sendErrorResponse(res, "4.04", "Not Found");
             return;
         }
 
@@ -650,8 +644,19 @@ export default class CoapServer implements ProtocolServer {
             return;
         }
 
-        // subscribeevent
-        if (req.headers.Observe === 0) {
+        const observe = req.headers.Observe;
+
+        if (observe == null) {
+            debug(
+                `CoapServer on port ${this.getPort()} rejects '${affordanceKey}' read from ${Helpers.toUriLiteral(
+                    req.rsinfo.address
+                )}:${req.rsinfo.port}`
+            );
+            this.sendErrorResponse(res, "4.00", "No Observe Option");
+            return;
+        }
+
+        if (observe === 0) {
             // work-around to avoid duplicate requests (resend due to no response)
             // (node-coap does not deduplicate when Observe is set)
             const packet = res._packet;
@@ -703,7 +708,7 @@ export default class CoapServer implements ProtocolServer {
                 );
                 thing.handleUnsubscribeEvent(affordanceKey, listener, options);
             });
-        } else if (req.headers.Observe > 0) {
+        } else if (observe > 0) {
             debug(
                 `CoapServer on port ${this.getPort()} sends '${affordanceKey}' response to ${Helpers.toUriLiteral(
                     req.rsinfo.address
@@ -712,34 +717,27 @@ export default class CoapServer implements ProtocolServer {
             // TODO: Check if this has been fixed in the meantime
             // node-coap does not support GET cancellation
             this.sendErrorResponse(res, "5.01", "node-coap issue: no GET cancellation, send RST");
-        } else {
-            debug(
-                `CoapServer on port ${this.getPort()} rejects '${affordanceKey}' read from ${Helpers.toUriLiteral(
-                    req.rsinfo.address
-                )}:${req.rsinfo.port}`
-            );
-            res.code = "4.00";
-            res.end("No Observe Option");
         }
     }
 
-    private getContentTypeFromRequest(req: IncomingMessage): string | undefined {
+    private getContentTypeFromRequest(req: IncomingMessage): string {
         const contentType = req.headers["Content-Format"] as string;
 
-        if (req.method === "PUT" || req.method === "POST") {
-            if (contentType != null && req.payload.length > 0) {
-                warn(
-                    `CoapServer on port ${this.getPort()} received no Content-Format from ${Helpers.toUriLiteral(
-                        req.rsinfo.address
-                    )}:${req.rsinfo.port}`
-                );
-                return ContentSerdes.DEFAULT;
-            } else if (ContentSerdes.get().getSupportedMediaTypes().includes(ContentSerdes.getMediaType(contentType))) {
-                throw Error("Unsupported Media Type");
-            }
+        if (contentType == null) {
+            warn(
+                `CoapServer on port ${this.getPort()} received no Content-Format from ${Helpers.toUriLiteral(
+                    req.rsinfo.address
+                )}:${req.rsinfo.port}`
+            );
         }
 
-        return undefined;
+        return contentType ?? ContentSerdes.DEFAULT;
+    }
+
+    private checkContentTypeSupportForInput(res: OutgoingMessage, method: string, contentType: string) {
+        const methodsWithPayload: string[] = ["PUT", "POST", "FETCH", "iPATCH", "PATCH"];
+
+        return methodsWithPayload.includes(method) && ContentSerdes.get().getSupportedMediaTypes().includes(ContentSerdes.getMediaType(contentType));
     }
 
     private getThingDescriptionPayload() {
@@ -753,6 +751,16 @@ export default class CoapServer implements ProtocolServer {
         );
     }
 
+    private parseUriSegments(requestUri: string) {
+        const segments = decodeURI(requestUri).split("/");
+
+        return {
+            thingKey: segments[1],
+            affordanceType: segments[2],
+            affordanceKey: segments[3],
+        }
+    }
+
     private sendErrorResponse(res: OutgoingMessage, errorCode: string, errorMessage: string) {
         res.code = errorCode;
         res.end(errorMessage);