diff --git a/modules/birthday/birthdaybase.go b/modules/birthday/birthdaybase.go
index fe40179..aba9dcc 100644
--- a/modules/birthday/birthdaybase.go
+++ b/modules/birthday/birthdaybase.go
@@ -43,12 +43,14 @@ type birthdayBase struct {
 }
 
 type birthdayEntry struct {
-	ID      uint64 `database:"id"`
-	Day     int    `database:"day"`
-	Month   int    `database:"month"`
-	Year    int    `database:"year"`
-	Visible bool   `database:"visible"`
-	time    time.Time
+	ID          uint64 `database:"id"`
+	Day         int    `database:"day"`
+	Month       int    `database:"month"`
+	Year        int    `database:"year"`
+	Visible     bool   `database:"visible"`
+	time        time.Time
+	GuildIDsRaw string `database:"guilds"`
+	GuildIDs    []string
 }
 
 // Returns a readable Form of the date
@@ -108,15 +110,75 @@ func (b birthdayEntry) Age() int {
 	return b.Next().Year() - b.Year - 1
 }
 
+// ParseGuildIDs splits the guild IDs into a slice and stores them in b.GuildIDs.
+func (b *birthdayEntry) ParseGuildIDs() {
+	b.GuildIDs = strings.Split(b.GuildIDsRaw, ",")
+}
+
+// IsInGuild returns true if the guildID is in b.GuildIDs.
+// If guildID is empty, IsInGuild returns true.
+func (b birthdayEntry) IsInGuild(guildID string) bool {
+	if guildID == "" {
+		return true
+	}
+	return util.ContainsString(b.GuildIDs, guildID)
+}
+
+// SetGuild sets the guildID in the birthday entry.
+func (b *birthdayEntry) SetGuild(guildID string) {
+	b.GuildIDsRaw += guildID
+	b.ParseGuildIDs()
+}
+
+// AddGuild adds the guildID to the birthday entry.
+func (b *birthdayEntry) AddGuild(guildID string) error {
+	if util.ContainsString(b.GuildIDs, guildID) {
+		return nil
+	} else if len(b.GuildIDs) >= 3 {
+		return fmt.Errorf("this entry already has %d guilds", len(b.GuildIDs))
+	}
+	b.GuildIDsRaw += "," + guildID
+	b.GuildIDsRaw = strings.Trim(b.GuildIDsRaw, ", ")
+	b.ParseGuildIDs()
+	return nil
+}
+
+// IsEqual returns true if b and b2 are equal.
+//
+// That is, if all of the following are true
+//  1. They have the same user ID.
+//  2. They are on the same date.
+//  3. They have the same visibility.
+//  4. They have the same guilds in (any order).
+func (b birthdayEntry) IsEqual(b2 birthdayEntry) bool {
+	if b.ID != b2.ID || b.Day != b2.Day || b.Month != b2.Month || b.Year != b2.Year || b.Visible != b2.Visible {
+		return false
+	}
+
+	// check for same guilds in any order
+	for _, guildID := range b.GuildIDs {
+		if !util.ContainsString(b2.GuildIDs, guildID) {
+			return false
+		}
+	}
+	for _, guildID := range b2.GuildIDs {
+		if !util.ContainsString(b.GuildIDs, guildID) {
+			return false
+		}
+	}
+	return true
+}
+
 // getBirthday copies all birthday fields into the struct pointed at by b.
 //
 // If the user from b.ID is not found it returns sql.ErrNoRows.
 func (cmd birthdayBase) getBirthday(b *birthdayEntry) (err error) {
-	row := database.QueryRow("SELECT day,month,year,visible FROM birthdays WHERE id=?", b.ID)
-	err = row.Scan(&b.Day, &b.Month, &b.Year, &b.Visible)
+	row := database.QueryRow("SELECT day,month,year,visible,guilds FROM birthdays WHERE id=?", b.ID)
+	err = row.Scan(&b.Day, &b.Month, &b.Year, &b.Visible, &b.GuildIDsRaw)
 	if err != nil {
 		return err
 	}
+	b.ParseGuildIDs()
 	return b.ParseTime()
 }
 
@@ -127,27 +189,36 @@ func (cmd birthdayBase) hasBirthday(id uint64) (hasBirthday bool, err error) {
 }
 
 // setBirthday inserts a new database entry with the values from b.
-func (cmd birthdayBase) setBirthday(b birthdayEntry) error {
-	_, err := database.Exec("INSERT INTO birthdays(id,day,month,year,visible) VALUES(?,?,?,?,?);", b.ID, b.Day, b.Month, b.Year, b.Visible)
+func (cmd birthdayBase) setBirthday(b *birthdayEntry) (err error) {
+	b.SetGuild(cmd.Interaction.GuildID)
+	_, err = database.Exec("INSERT INTO birthdays(id,day,month,year,visible,guilds) VALUES(?,?,?,?,?);", b.ID, b.Day, b.Month, b.Year, b.Visible, b.GuildIDsRaw)
 	return err
 }
 
 // updateBirthday updates an existing database entry with the values from b.
-func (cmd birthdayBase) updateBirthday(b birthdayEntry) (before birthdayEntry, err error) {
-	err = b.ParseTime()
-	if err != nil {
-		return birthdayEntry{}, err
-	}
+func (cmd birthdayBase) updateBirthday(b *birthdayEntry) (before birthdayEntry, err error) {
 	before.ID = b.ID
 	if err = cmd.getBirthday(&before); err != nil {
 		return birthdayEntry{}, fmt.Errorf("trying to get old birthday: %v", err)
 	}
+	b.GuildIDsRaw = before.GuildIDsRaw
+	b.ParseGuildIDs()
+
+	err = b.AddGuild(cmd.Interaction.GuildID)
+	if err != nil {
+		return birthdayEntry{}, fmt.Errorf("adding guild '%s' to birthday entry: %v", cmd.Interaction.GuildID, err)
+	}
+
+	// early return if nothing changed
+	if b.IsEqual(before) {
+		return before, nil
+	}
 
 	var (
 		updateNames []string
 		updateVars  []any
 		oldV        reflect.Value = reflect.ValueOf(before)
-		v           reflect.Value = reflect.ValueOf(b)
+		v           reflect.Value = reflect.ValueOf(*b)
 	)
 	for i := 0; i < v.NumField(); i++ {
 		var (
@@ -160,11 +231,11 @@ func (cmd birthdayBase) updateBirthday(b birthdayEntry) (before birthdayEntry, e
 			continue
 		}
 
+		tag := v.Type().Field(i).Tag.Get("database")
+		if tag == "" {
+			continue
+		}
 		if f.Interface() != oldF.Interface() {
-			tag := v.Type().Field(i).Tag.Get("database")
-			if tag == "" {
-				continue
-			}
 			updateNames = append(updateNames, tag)
 			updateVars = append(updateVars, f.Interface())
 		}
@@ -193,8 +264,8 @@ func (cmd birthdayBase) removeBirthday(id uint64) (birthdayEntry, error) {
 	return b, err
 }
 
-// getBirthdaysMonth return a sorted slice of birthday entries that matches the given month.
-func (cmd birthdayBase) getBirthdaysMonth(month int) (birthdays []birthdayEntry, err error) {
+// getBirthdaysMonth return a sorted slice of birthday entries that matches the given guildID and month.
+func (cmd birthdayBase) getBirthdaysMonth(guildID string, month int) (birthdays []birthdayEntry, err error) {
 	var numOfEntries int64
 	err = database.QueryRow("SELECT COUNT(*) FROM birthdays WHERE month=?", month).Scan(&numOfEntries)
 	if err != nil {
@@ -206,7 +277,7 @@ func (cmd birthdayBase) getBirthdaysMonth(month int) (birthdays []birthdayEntry,
 		return birthdays, nil
 	}
 
-	rows, err := database.Query("SELECT id,day,year,visible FROM birthdays WHERE month=?", month)
+	rows, err := database.Query("SELECT id,day,year,visible,guilds FROM birthdays WHERE month=?", month)
 	if err != nil {
 		return birthdays, err
 	}
@@ -214,12 +285,13 @@ func (cmd birthdayBase) getBirthdaysMonth(month int) (birthdays []birthdayEntry,
 
 	for rows.Next() {
 		b := birthdayEntry{Month: month}
-		err = rows.Scan(&b.ID, &b.Day, &b.Year, &b.Visible)
+		err = rows.Scan(&b.ID, &b.Day, &b.Year, &b.Visible, &b.GuildIDsRaw)
 		if err != nil {
 			return birthdays, err
 		}
+		b.ParseGuildIDs()
 
-		if !b.Visible {
+		if !b.Visible || !b.IsInGuild(guildID) {
 			continue
 		}
 
@@ -238,8 +310,8 @@ func (cmd birthdayBase) getBirthdaysMonth(month int) (birthdays []birthdayEntry,
 	return birthdays, nil
 }
 
-// getBirthdaysDate return a slice of birthday entries that matches the given date.
-func getBirthdaysDate(day int, month int) (birthdays []birthdayEntry, err error) {
+// getBirthdaysDate return a slice of birthday entries that matches the given guildID and date.
+func getBirthdaysDate(guildID string, day int, month int) (birthdays []birthdayEntry, err error) {
 	var numOfEntries int64
 	err = database.QueryRow("SELECT COUNT(*) FROM birthdays WHERE day=? AND month=?", day, month).Scan(&numOfEntries)
 	if err != nil {
@@ -251,7 +323,7 @@ func getBirthdaysDate(day int, month int) (birthdays []birthdayEntry, err error)
 		return birthdays, nil
 	}
 
-	rows, err := database.Query("SELECT id,year,visible FROM birthdays WHERE day=? AND month=?", day, month)
+	rows, err := database.Query("SELECT id,year,visible,guilds FROM birthdays WHERE day=? AND month=?", day, month)
 	if err != nil {
 		return birthdays, err
 	}
@@ -259,12 +331,13 @@ func getBirthdaysDate(day int, month int) (birthdays []birthdayEntry, err error)
 
 	for rows.Next() {
 		b := birthdayEntry{Day: day, Month: month}
-		err = rows.Scan(&b.ID, &b.Year, &b.Visible)
+		err = rows.Scan(&b.ID, &b.Year, &b.Visible, &b.GuildIDsRaw)
 		if err != nil {
 			return birthdays, err
 		}
+		b.ParseGuildIDs()
 
-		if !b.Visible {
+		if !b.Visible || !b.IsInGuild(guildID) {
 			continue
 		}
 
diff --git a/modules/birthday/handleCheck.go b/modules/birthday/handleCheck.go
index 30a7c8c..7969ca2 100644
--- a/modules/birthday/handleCheck.go
+++ b/modules/birthday/handleCheck.go
@@ -35,14 +35,6 @@ func Check(s *discordgo.Session) {
 	defer rows.Close()
 
 	now := time.Now()
-	birthdays, err := getBirthdaysDate(now.Day(), int(now.Month()))
-	if err != nil {
-		log.Printf("Error on getting todays birthdays from database: %v\n", err)
-	}
-	e, n := birthdayAnnounceEmbed(s, birthdays)
-	if n <= 0 {
-		return
-	}
 
 	for rows.Next() {
 		err = rows.Scan(&guildID, &channelID)
@@ -50,6 +42,9 @@ func Check(s *discordgo.Session) {
 			log.Printf("Error on scanning birthday channel ID from database %v\n", err)
 			continue
 		}
+		if channelID == 0 {
+			continue
+		}
 
 		channel, err := s.Channel(fmt.Sprint(channelID))
 		if err != nil {
@@ -61,6 +56,15 @@ func Check(s *discordgo.Session) {
 			return
 		}
 
+		birthdays, err := getBirthdaysDate(fmt.Sprint(guildID), now.Day(), int(now.Month()))
+		if err != nil {
+			log.Printf("Error on getting todays birthdays from guild %s from database: %v\n", fmt.Sprint(guildID), err)
+		}
+		e, n := birthdayAnnounceEmbed(s, fmt.Sprint(guildID), birthdays)
+		if n <= 0 {
+			return
+		}
+
 		// announce
 		_, err = s.ChannelMessageSendEmbed(channel.ID, e)
 		if err != nil {
@@ -71,7 +75,7 @@ func Check(s *discordgo.Session) {
 
 // birthdayAnnounceEmbed returns the embed, that contains all birthdays and 'n' as the number of
 // birthdays, which is always len(b)
-func birthdayAnnounceEmbed(s *discordgo.Session, b []birthdayEntry) (e *discordgo.MessageEmbed, n int) {
+func birthdayAnnounceEmbed(s *discordgo.Session, guildID string, b []birthdayEntry) (e *discordgo.MessageEmbed, n int) {
 	var title, fValue string
 
 	switch len(b) {
@@ -85,14 +89,17 @@ func birthdayAnnounceEmbed(s *discordgo.Session, b []birthdayEntry) (e *discordg
 	}
 
 	for _, b := range b {
-		mention := fmt.Sprintf("<@%d>", b.ID)
+		member := util.IsGuildMember(s, guildID, fmt.Sprint(b.ID))
+		if member == nil {
+			continue
+		}
 
 		if b.Year == 0 {
-			fValue += fmt.Sprintf("%s\n", mention)
+			fValue += fmt.Sprintf("%s\n", member.Mention())
 		} else {
 			format := lang.Get(tp+"msg.announce.with_age", lang.FallbackLang())
 			format += "\n"
-			fValue += fmt.Sprintf(format, mention, fmt.Sprint(b.Age()))
+			fValue += fmt.Sprintf(format, member.Mention(), fmt.Sprint(b.Age()))
 		}
 	}
 
diff --git a/modules/birthday/handlerSubcommandAnnounce.go b/modules/birthday/handlerSubcommandAnnounce.go
index 82d5a33..2f50bc0 100644
--- a/modules/birthday/handlerSubcommandAnnounce.go
+++ b/modules/birthday/handlerSubcommandAnnounce.go
@@ -37,14 +37,14 @@ func (cmd Chat) subcommandAnnounce() subcommandAnnounce {
 
 func (cmd subcommandAnnounce) handler() {
 	now := time.Now()
-	b, err := getBirthdaysDate(now.Day(), int(now.Month()))
+	b, err := getBirthdaysDate(cmd.Interaction.GuildID, now.Day(), int(now.Month()))
 	if err != nil {
-		log.Printf("Error on announce birthday: %v\n", err)
+		log.Printf("Error on announce birthday in guild %s: %v\n", cmd.Interaction.GuildID, err)
 		cmd.ReplyError()
 		return
 	}
 
-	e, n := birthdayAnnounceEmbed(cmd.Session, b)
+	e, n := birthdayAnnounceEmbed(cmd.Session, cmd.Interaction.GuildID, b)
 
 	if n <= 0 {
 		cmd.ReplyHiddenEmbed(e)
diff --git a/modules/birthday/handlerSubcommandList.go b/modules/birthday/handlerSubcommandList.go
index 238804f..40b4eb5 100644
--- a/modules/birthday/handlerSubcommandList.go
+++ b/modules/birthday/handlerSubcommandList.go
@@ -49,9 +49,9 @@ func (cmd subcommandList) handler() {
 	}
 	month := int(cmd.month.IntValue())
 
-	birthdays, err := cmd.getBirthdaysMonth(month)
+	birthdays, err := cmd.getBirthdaysMonth(cmd.Interaction.GuildID, month)
 	if err != nil {
-		log.Printf("Error on get birthdays by month: %v\n", err)
+		log.Printf("Error on get birthdays by month from guild %s: %v\n", cmd.Interaction.GuildID, err)
 		cmd.ReplyError()
 		return
 	}
diff --git a/modules/birthday/handlerSubcommandSet.go b/modules/birthday/handlerSubcommandSet.go
index bd97d93..02e5fca 100644
--- a/modules/birthday/handlerSubcommandSet.go
+++ b/modules/birthday/handlerSubcommandSet.go
@@ -121,7 +121,7 @@ func (cmd subcommandSet) interactionHandler() {
 		return
 	}
 
-	b := birthdayEntry{
+	b := &birthdayEntry{
 		ID:      authorID,
 		Day:     int(cmd.day.IntValue()),
 		Month:   int(cmd.month.IntValue()),
@@ -194,13 +194,13 @@ func (cmd subcommandSet) interactionHandler() {
 }
 
 // seperate handler for an update of the birthday
-func (cmd subcommandSet) handleUpdate(b birthdayEntry, e *discordgo.MessageEmbed) error {
+func (cmd subcommandSet) handleUpdate(b *birthdayEntry, e *discordgo.MessageEmbed) (err error) {
 	before, err := cmd.updateBirthday(b)
 	if err != nil {
 		return err
 	}
 
-	if b == before {
+	if b.IsEqual(before) {
 		var age string
 		if b.Year > 0 {
 			age = fmt.Sprintf(" (%d)", b.Age()+1)
diff --git a/util/discord.go b/util/discord.go
index e0b6ef1..7b89314 100644
--- a/util/discord.go
+++ b/util/discord.go
@@ -437,3 +437,24 @@ func MessageComplexWebhookEdit(src any) *discordgo.WebhookEdit {
 		panic("Given source type is not supported: " + fmt.Sprintf("%T", src))
 	}
 }
+
+// IsGuildMember returns the given user as a member of the given guild. If the
+// user is not a member of the guild IsGuildMember returns nil.
+func IsGuildMember(s *discordgo.Session, guildID, userID string) (member *discordgo.Member) {
+	member, err := s.State.Member(guildID, userID)
+	if err == nil {
+		return member
+	} else if err != discordgo.ErrStateNotFound {
+		log.Printf("ERROR: Failed to get guild member from cache (G: %s, U: %s): %v\n", guildID, userID, err)
+	}
+	member, err = s.GuildMember(guildID, userID)
+	if err == nil {
+		return member
+	}
+
+	var restErr *discordgo.RESTError
+	if !errors.As(err, &restErr) || restErr.Response.StatusCode != http.StatusNotFound {
+		log.Printf("ERROR: Failed to get guild member from API (G: %s, U: %s): %v\n", guildID, userID, err)
+	}
+	return nil
+}