diff --git a/irc/channel.go b/irc/channel.go
index 247e7cba..ff299447 100644
--- a/irc/channel.go
+++ b/irc/channel.go
@@ -371,17 +371,22 @@ func (channel *Channel) CanSpeak(client *Client) bool {
 	return true
 }
 
+// TagMsg sends a tag message to everyone in this channel who can accept them.
+func (channel *Channel) TagMsg(minPrefix *ChannelMode, clientOnlyTags *map[string]ircmsg.TagValue, client *Client) {
+	channel.sendMessage("TAGMSG", []Capability{MessageTags}, minPrefix, clientOnlyTags, client, nil)
+}
+
 // PrivMsg sends a private message to everyone in this channel.
 func (channel *Channel) PrivMsg(minPrefix *ChannelMode, clientOnlyTags *map[string]ircmsg.TagValue, client *Client, message string) {
-	channel.sendMessage("PRIVMSG", minPrefix, clientOnlyTags, client, message)
+	channel.sendMessage("PRIVMSG", nil, minPrefix, clientOnlyTags, client, &message)
 }
 
 // Notice sends a private message to everyone in this channel.
 func (channel *Channel) Notice(minPrefix *ChannelMode, clientOnlyTags *map[string]ircmsg.TagValue, client *Client, message string) {
-	channel.sendMessage("NOTICE", minPrefix, clientOnlyTags, client, message)
+	channel.sendMessage("NOTICE", nil, minPrefix, clientOnlyTags, client, &message)
 }
 
-func (channel *Channel) sendMessage(cmd string, minPrefix *ChannelMode, clientOnlyTags *map[string]ircmsg.TagValue, client *Client, message string) {
+func (channel *Channel) sendMessage(cmd string, requiredCaps []Capability, minPrefix *ChannelMode, clientOnlyTags *map[string]ircmsg.TagValue, client *Client, message *string) {
 	if !channel.CanSpeak(client) {
 		client.Send(nil, client.server.name, ERR_CANNOTSENDTOCHAN, channel.name, "Cannot send to channel")
 		return
@@ -403,10 +408,29 @@ func (channel *Channel) sendMessage(cmd string, minPrefix *ChannelMode, clientOn
 		if member == client && !client.capabilities[EchoMessage] {
 			continue
 		}
+
+		canReceive := true
+		for _, capName := range requiredCaps {
+			if !member.capabilities[capName] {
+				canReceive = false
+			}
+		}
+		if !canReceive {
+			continue
+		}
+
 		if member.capabilities[MessageTags] {
-			member.SendFromClient(client, clientOnlyTags, client.nickMaskString, cmd, channel.name, message)
+			if message == nil {
+				member.SendFromClient(client, clientOnlyTags, client.nickMaskString, cmd, channel.name)
+			} else {
+				member.SendFromClient(client, clientOnlyTags, client.nickMaskString, cmd, channel.name, *message)
+			}
 		} else {
-			member.SendFromClient(client, nil, client.nickMaskString, cmd, channel.name, message)
+			if message == nil {
+				member.SendFromClient(client, nil, client.nickMaskString, cmd, channel.name)
+			} else {
+				member.SendFromClient(client, nil, client.nickMaskString, cmd, channel.name, *message)
+			}
 		}
 	}
 }
diff --git a/irc/commands.go b/irc/commands.go
index b3bb056c..ee27a5bd 100644
--- a/irc/commands.go
+++ b/irc/commands.go
@@ -191,6 +191,10 @@ var Commands = map[string]Command{
 		handler:   sceneHandler,
 		minParams: 2,
 	},
+	"TAGMSG": {
+		handler:   tagmsgHandler,
+		minParams: 1,
+	},
 	"QUIT": {
 		handler:      quitHandler,
 		usablePreReg: true,
diff --git a/irc/help.go b/irc/help.go
index e0d726c8..91ed9b07 100644
--- a/irc/help.go
+++ b/irc/help.go
@@ -300,6 +300,12 @@ Gives the given user a new nickname.`,
 		text: `SCENE <target> <text to be sent>
 
 The SCENE command is used to send a scene notification to the given target.`,
+	},
+	"tagmsg": {
+		text: `@+client-only-tags TAGMSG <target>{,<target>}
+
+Sends the given client-only tags to the given targets as a TAGMSG. See the IRCv3
+specs for more info: http://ircv3.net/specs/core/message-tags-3.3.html`,
 	},
 	"quit": {
 		text: `QUIT [reason]
diff --git a/irc/message_tags.go b/irc/message_tags.go
index 7ef5496e..b45a67ac 100644
--- a/irc/message_tags.go
+++ b/irc/message_tags.go
@@ -19,5 +19,9 @@ func GetClientOnlyTags(tags map[string]ircmsg.TagValue) *map[string]ircmsg.TagVa
 		}
 	}
 
+	if len(clientOnlyTags) < 1 {
+		return nil
+	}
+
 	return &clientOnlyTags
 }
diff --git a/irc/server.go b/irc/server.go
index ed585721..da7860b4 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -338,7 +338,7 @@ func (server *Server) setISupport() {
 	server.isupport.Add("RPCHAN", "E")
 	server.isupport.Add("RPUSER", "E")
 	server.isupport.Add("STATUSMSG", "~&@%+")
-	server.isupport.Add("TARGMAX", fmt.Sprintf("NAMES:1,LIST:1,KICK:1,WHOIS:1,PRIVMSG:%s,NOTICE:%s,MONITOR:", maxTargetsString, maxTargetsString))
+	server.isupport.Add("TARGMAX", fmt.Sprintf("NAMES:1,LIST:1,KICK:1,WHOIS:1,PRIVMSG:%s,TAGMSG:%s,NOTICE:%s,MONITOR:", maxTargetsString, maxTargetsString, maxTargetsString))
 	server.isupport.Add("TOPICLEN", strconv.Itoa(server.limits.TopicLen))
 
 	// account registration
@@ -963,6 +963,63 @@ func privmsgHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool
 	return false
 }
 
+// TAGMSG <target>{,<target>}
+func tagmsgHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
+	clientOnlyTags := GetClientOnlyTags(msg.Tags)
+	// no client-only tags, so we can drop it
+	if clientOnlyTags == nil {
+		return false
+	}
+
+	targets := strings.Split(msg.Params[0], ",")
+
+	for i, targetString := range targets {
+		// max of four targets per privmsg
+		if i > maxTargets-1 {
+			break
+		}
+		prefixes, targetString := SplitChannelMembershipPrefixes(targetString)
+		lowestPrefix := GetLowestChannelModePrefix(prefixes)
+
+		// eh, no need to notify them
+		if len(targetString) < 1 {
+			continue
+		}
+
+		target, err := CasefoldChannel(targetString)
+		if err == nil {
+			channel := server.channels.Get(target)
+			if channel == nil {
+				client.Send(nil, server.name, ERR_NOSUCHCHANNEL, client.nick, targetString, "No such channel")
+				continue
+			}
+			channel.TagMsg(lowestPrefix, clientOnlyTags, client)
+		} else {
+			target, err = CasefoldName(targetString)
+			user := server.clients.Get(target)
+			if err != nil || user == nil {
+				if len(target) > 0 {
+					client.Send(nil, server.name, ERR_NOSUCHNICK, target, "No such nick")
+				}
+				continue
+			}
+			// end user can't receive tagmsgs
+			if !user.capabilities[MessageTags] {
+				continue
+			}
+			user.SendFromClient(client, clientOnlyTags, "TAGMSG", user.nick)
+			if client.capabilities[EchoMessage] {
+				client.SendFromClient(client, clientOnlyTags, "TAGMSG", user.nick)
+			}
+			if user.flags[Away] {
+				//TODO(dan): possibly implement cooldown of away notifications to users
+				client.Send(nil, server.name, RPL_AWAY, user.nick, user.awayMessage)
+			}
+		}
+	}
+	return false
+}
+
 func (client *Client) WhoisChannelsNames(target *Client) []string {
 	isMultiPrefix := target.capabilities[MultiPrefix]
 	var chstrs []string