diff --git a/cmd/signaldctl/cmd/group/addmember/add-member.go b/cmd/signaldctl/cmd/group/addmember/add-member.go
index 73464bc..54bc20f 100644
--- a/cmd/signaldctl/cmd/group/addmember/add-member.go
+++ b/cmd/signaldctl/cmd/group/addmember/add-member.go
@@ -52,7 +52,10 @@ var (
 			}
 			group = args[0]
 			for _, member := range args[1:] {
-				address := common.StringToAddress(member)
+				address, err := common.StringToAddress(member)
+				if err != nil {
+					log.Fatal(err)
+				}
 				members = append(members, &address)
 			}
 		},
diff --git a/cmd/signaldctl/cmd/group/create/create-group.go b/cmd/signaldctl/cmd/group/create/create-group.go
index 8fdefb5..ca47d72 100644
--- a/cmd/signaldctl/cmd/group/create/create-group.go
+++ b/cmd/signaldctl/cmd/group/create/create-group.go
@@ -58,7 +58,10 @@ var (
 			}
 
 			for _, member := range args[1:] {
-				address := common.StringToAddress(member)
+				address, err := common.StringToAddress(member)
+				if err != nil {
+					log.Fatal(err)
+				}
 				req.Members = append(req.Members, &address)
 			}
 
diff --git a/cmd/signaldctl/cmd/group/removemember/remove-member.go b/cmd/signaldctl/cmd/group/removemember/remove-member.go
index 49a2a6c..436496c 100644
--- a/cmd/signaldctl/cmd/group/removemember/remove-member.go
+++ b/cmd/signaldctl/cmd/group/removemember/remove-member.go
@@ -52,7 +52,10 @@ var (
 			}
 			group = args[0]
 			for _, member := range args[1:] {
-				address := common.StringToAddress(member)
+				address, err := common.StringToAddress(member)
+				if err != nil {
+					log.Fatal(err)
+				}
 				members = append(members, &address)
 			}
 		},
diff --git a/cmd/signaldctl/cmd/group/update/role/update-group-role.go b/cmd/signaldctl/cmd/group/update/role/update-group-role.go
index 8568b0d..5c69ab9 100644
--- a/cmd/signaldctl/cmd/group/update/role/update-group-role.go
+++ b/cmd/signaldctl/cmd/group/update/role/update-group-role.go
@@ -52,7 +52,11 @@ var (
 				log.Fatal("not enough arguments provided")
 			}
 			group = args[0]
-			address = common.StringToAddress(args[1])
+			var err error
+			address, err = common.StringToAddress(args[1])
+			if err != nil {
+				log.Fatal(err)
+			}
 			switch strings.ToLower(args[2]) {
 			case "default":
 				role = "DEFAULT"
diff --git a/cmd/signaldctl/cmd/key/list/list-keys.go b/cmd/signaldctl/cmd/key/list/list-keys.go
index b20ca26..20ee54d 100644
--- a/cmd/signaldctl/cmd/key/list/list-keys.go
+++ b/cmd/signaldctl/cmd/key/list/list-keys.go
@@ -44,7 +44,10 @@ var (
 				log.Fatal("No account specified. Please specify with --account or set a default")
 			}
 			if len(args) >= 1 {
-				a := common.StringToAddress(args[0])
+				a, err := common.StringToAddress(args[0])
+				if err != nil {
+					log.Fatal(err)
+				}
 				address = &a
 			}
 		},
diff --git a/cmd/signaldctl/cmd/key/qr/qr-key.go b/cmd/signaldctl/cmd/key/qr/qr-key.go
index 205db36..8ad927d 100644
--- a/cmd/signaldctl/cmd/key/qr/qr-key.go
+++ b/cmd/signaldctl/cmd/key/qr/qr-key.go
@@ -50,7 +50,11 @@ var (
 				common.Must(cmd.Help())
 				log.Fatal("please specify an address")
 			}
-			address = common.StringToAddress(args[0])
+			var err error
+			address, err = common.StringToAddress(args[0])
+			if err != nil {
+				log.Fatal(err)
+			}
 			if len(args) > 1 {
 				safetyNumber = args[1]
 			}
diff --git a/cmd/signaldctl/cmd/key/trust/trust-key.go b/cmd/signaldctl/cmd/key/trust/trust-key.go
index 6dd0195..da2224c 100644
--- a/cmd/signaldctl/cmd/key/trust/trust-key.go
+++ b/cmd/signaldctl/cmd/key/trust/trust-key.go
@@ -46,7 +46,11 @@ var (
 				common.Must(cmd.Help())
 				log.Fatal("please specify an address and a safety number")
 			}
-			address = common.StringToAddress(args[0])
+			var err error
+			address, err = common.StringToAddress(args[0])
+			if err != nil {
+				log.Fatal(err)
+			}
 			safetyNumber = args[1]
 			if len(args) > 2 {
 				level = strings.ToUpper(args[2])
diff --git a/cmd/signaldctl/cmd/key/trust_all/trust-all.go b/cmd/signaldctl/cmd/key/trust_all/trust-all.go
index 3eb10a2..e474b2c 100644
--- a/cmd/signaldctl/cmd/key/trust_all/trust-all.go
+++ b/cmd/signaldctl/cmd/key/trust_all/trust-all.go
@@ -44,7 +44,11 @@ var (
 				log.Fatal("No account specified. Please specify with --account or set a default")
 			}
 			for _, address := range args {
-				addresses = append(addresses, common.StringToAddress(address))
+				address, err := common.StringToAddress(address)
+				if err != nil {
+					log.Fatal(err)
+				}
+				addresses = append(addresses, address)
 			}
 		},
 		Run: func(_ *cobra.Command, _ []string) {
diff --git a/cmd/signaldctl/cmd/message/react/react-to-message.go b/cmd/signaldctl/cmd/message/react/react-to-message.go
index be66ebc..d91c2f3 100644
--- a/cmd/signaldctl/cmd/message/react/react-to-message.go
+++ b/cmd/signaldctl/cmd/message/react/react-to-message.go
@@ -53,8 +53,11 @@ var (
 			if len(args) != 3 {
 				common.Must(cmd.Help())
 			}
-			author = common.StringToAddress(args[0])
 			var err error
+			author, err = common.StringToAddress(args[0])
+			if err != nil {
+				log.Fatal(err)
+			}
 			timestamp, err = strconv.ParseInt(args[1], 10, 64)
 			if err != nil {
 				log.Fatal("Unable to parse timestamp", args[1], ":", err.Error())
diff --git a/cmd/signaldctl/cmd/message/send/send-message.go b/cmd/signaldctl/cmd/message/send/send-message.go
index b0cd39d..f8bf02c 100644
--- a/cmd/signaldctl/cmd/message/send/send-message.go
+++ b/cmd/signaldctl/cmd/message/send/send-message.go
@@ -35,6 +35,8 @@ import (
 
 var (
 	account     string
+	toAddress   *v1.JsonAddress
+	toGroup     string
 	attachments []string
 
 	SendMessageCmd = &cobra.Command{
@@ -52,20 +54,22 @@ var (
 				common.Must(cmd.Help())
 				log.Fatal("must specify both destination (either group id or phone number) and message")
 			}
+			to, err := common.StringToAddress(args[0])
+			if err != nil {
+				toGroup = args[0]
+			} else {
+				toAddress = &to
+			}
 		},
 		Run: func(_ *cobra.Command, args []string) {
 			go common.Signald.Listen(nil)
 
 			req := v1.SendRequest{
-				Username:    account,
-				MessageBody: strings.Join(args[1:], " "),
-				Attachments: []*v0.JsonAttachment{},
-			}
-
-			if strings.HasPrefix(args[0], "+") {
-				req.RecipientAddress = &v1.JsonAddress{Number: args[0]}
-			} else {
-				req.RecipientGroupID = args[0]
+				Username:         account,
+				MessageBody:      strings.Join(args[1:], " "),
+				Attachments:      []*v0.JsonAttachment{},
+				RecipientAddress: toAddress,
+				RecipientGroupID: toGroup,
 			}
 
 			for _, attachment := range attachments {
diff --git a/cmd/signaldctl/common/signald.go b/cmd/signaldctl/common/signald.go
index 8ffc145..3db14e8 100644
--- a/cmd/signaldctl/common/signald.go
+++ b/cmd/signaldctl/common/signald.go
@@ -1,9 +1,11 @@
 package common
 
 import (
+	"fmt"
 	"log"
 	"strings"
 
+	"github.com/google/uuid"
 	"github.com/jedib0t/go-pretty/v6/table"
 
 	"gitlab.com/signald/signald-go/signald"
@@ -30,6 +32,18 @@ var (
 	OutputFormat string
 )
 
+type InvalidAddressError struct {
+	invalidAddress string
+}
+
+func NewInvalidAddress(i string) InvalidAddressError {
+	return InvalidAddressError{invalidAddress: i}
+}
+
+func (i InvalidAddressError) Error() string {
+	return fmt.Sprintf("invalid address: %s", i.invalidAddress)
+}
+
 func Must(err error) {
 	if err != nil {
 		log.Fatal(err)
@@ -40,9 +54,13 @@ func StylizeTable(t table.Writer) {
 	t.SetStyle(table.StyleLight)
 }
 
-func StringToAddress(address string) v1.JsonAddress {
+func StringToAddress(address string) (v1.JsonAddress, error) {
 	if strings.HasPrefix(address, "+") {
-		return v1.JsonAddress{Number: address}
+		return v1.JsonAddress{Number: address}, nil
 	}
-	return v1.JsonAddress{UUID: address}
+
+	if _, err := uuid.Parse(address); err == nil {
+		return v1.JsonAddress{UUID: address}, nil
+	}
+	return v1.JsonAddress{}, NewInvalidAddress(address)
 }
diff --git a/go.mod b/go.mod
index 6cc870b..a08f00b 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module gitlab.com/signald/signald-go
 go 1.14
 
 require (
+	github.com/google/uuid v1.3.0
 	github.com/jedib0t/go-pretty/v6 v6.1.0
 	github.com/kr/text v0.2.0 // indirect
 	github.com/mattn/go-runewidth v0.0.10 // indirect
diff --git a/go.sum b/go.sum
index b61d002..d22c029 100644
--- a/go.sum
+++ b/go.sum
@@ -65,6 +65,8 @@ github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXi
 github.com/google/pprof v0.0.0-20181206194817-3ea8567a2e57/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
 github.com/google/pprof v0.0.0-20190515194954-54271f7e092f/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
 github.com/google/renameio v0.1.0/go.mod h1:KWCgfxg9yswjAJkECMjeO8J8rahYeXnNhOm40UhjYkI=
+github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
 github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=