diff --git a/internal/gateway/methods/bitrix_portals.go b/internal/gateway/methods/bitrix_portals.go
index 4157f8d7..99eb35a7 100644
--- a/internal/gateway/methods/bitrix_portals.go
+++ b/internal/gateway/methods/bitrix_portals.go
@@ -71,7 +71,11 @@ type bitrixPortalView struct {
 var (
 	// Bitrix24 cloud portal hosts. Matches *.bitrix24.{com,eu,ru,de,fr,jp,in,kz,ua,by}
 	// plus self-hosted *.bitrix.info. Subdomain regex matches DNS label rules.
-	bitrixDomainRegex = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?\.(bitrix24\.(com|eu|ru|de|fr|jp|in|kz|ua|by)|bitrix\.info)$`)
+	bitrixCloudDomainRegex = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?\.(bitrix24\.(com|eu|ru|de|fr|jp|in|kz|ua|by)|bitrix\.info)$`)
+
+	// Valid hostname regex for self-hosted Bitrix24 instances (custom domains).
+	// Accepts any valid FQDN or hostname with optional port (e.g. bx.example.com, portal.internal:8443).
+	selfHostedDomainRegex = regexp.MustCompile(`^[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?(\.[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?)*(\:\d+)?$`)
 
 	// Portal name: lowercase slug used in install state token + channel config
 	// reference. Underscore allowed for legacy CLI-created portals.
@@ -142,8 +146,8 @@ func (m *BitrixPortalsMethods) handleCreate(ctx context.Context, client *gateway
 		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, i18n.T(locale, i18n.MsgInvalidRequest, "name: lowercase letters, digits, hyphen, underscore (2-64 chars)")))
 		return
 	}
-	if !bitrixDomainRegex.MatchString(domain) {
-		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, i18n.T(locale, i18n.MsgInvalidRequest, "domain: must be *.bitrix24.{com,eu,ru,…} or *.bitrix.info")))
+	if !bitrixCloudDomainRegex.MatchString(domain) && !selfHostedDomainRegex.MatchString(domain) {
+		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, i18n.T(locale, i18n.MsgInvalidRequest, "domain: must be a valid hostname (e.g. *.bitrix24.com, *.bitrix.info, or your self-hosted domain)")))
 		return
 	}
 	if clientID == "" || clientSecret == "" {
diff --git a/internal/gateway/methods/bitrix_portals_test.go b/internal/gateway/methods/bitrix_portals_test.go
index 1405267b..f2d9995b 100644
--- a/internal/gateway/methods/bitrix_portals_test.go
+++ b/internal/gateway/methods/bitrix_portals_test.go
@@ -369,7 +369,7 @@ func TestBitrixPortals_Create_InvalidDomain(t *testing.T) {
 	client, ch := gateway.NewCapturingTestClient(permissions.RoleAdmin, tid, "u", 4)
 	m.handleCreate(store.WithTenantID(context.Background(), tid), client, buildBitrixReq(t, protocol.MethodBitrixPortalsCreate, map[string]string{
 		"name":          "p",
-		"domain":        "not-a-bitrix-domain.com",
+		"domain":        "-invalid.com",
 		"client_id":     "x",
 		"client_secret": "y",
 	}))
@@ -380,6 +380,29 @@ func TestBitrixPortals_Create_InvalidDomain(t *testing.T) {
 	}
 }
 
+func TestBitrixPortals_Create_SelfHostedDomain(t *testing.T) {
+	tid := uuid.MustParse("22222222-2222-2222-2222-222222222222")
+	pStore := newStubBitrixPortalStore()
+	m := NewBitrixPortalsMethods(pStore, newStubChannelInstanceStore(), gatewayURLFn("https://goclaw.tamgiac.com"))
+
+	client, ch := gateway.NewCapturingTestClient(permissions.RoleAdmin, tid, "admin", 4)
+	m.handleCreate(store.WithTenantID(context.Background(), tid), client, buildBitrixReq(t, protocol.MethodBitrixPortalsCreate, map[string]string{
+		"name":          "myportal",
+		"domain":        "bx.mycompany.com",
+		"client_id":     "local.abc",
+		"client_secret": "secret123",
+	}))
+
+	resp := readResponse(t, ch)
+	if resp.Error != nil {
+		t.Fatalf("create with self-hosted domain failed: %+v", resp.Error)
+	}
+	result := resp.Payload.(map[string]any)
+	if result["domain"] != "bx.mycompany.com" {
+		t.Errorf("domain = %q, want bx.mycompany.com", result["domain"])
+	}
+}
+
 func TestBitrixPortals_Create_InvalidName(t *testing.T) {
 	tid := uuid.New()
 	m := NewBitrixPortalsMethods(newStubBitrixPortalStore(), newStubChannelInstanceStore(), gatewayURLFn("https://gw.example.com"))
@@ -543,19 +566,44 @@ func TestBitrixDomainRegex(t *testing.T) {
 	}
 	bad := []string{
 		"tamgiac.bitrix24",
-		"tamgiac.example.com",
 		"tamgiac.bitrix24.xx",
 		"-bad.bitrix24.com",
 		"UPPER.bitrix24.com", // we lowercase before match
 		"a.b.bitrix24.com",   // multi-level subdomain not allowed
 	}
 	for _, d := range good {
-		if !bitrixDomainRegex.MatchString(d) {
+		if !bitrixCloudDomainRegex.MatchString(d) {
 			t.Errorf("should accept %q", d)
 		}
 	}
 	for _, d := range bad {
-		if bitrixDomainRegex.MatchString(d) {
+		if bitrixCloudDomainRegex.MatchString(d) {
+			t.Errorf("should reject %q", d)
+		}
+	}
+}
+
+func TestSelfHostedDomainRegex(t *testing.T) {
+	good := []string{
+		"bx.example.com",
+		"portal.internal",
+		"bitrix.mycompany.co.uk",
+		"portal.example.com:8443",
+		"bx.corp",
+	}
+	bad := []string{
+		"-bad.example.com",
+		"UPPER.example.com", // we lowercase before match
+		"",
+		"not a domain",
+	}
+	for _, d := range good {
+		if !selfHostedDomainRegex.MatchString(d) {
+			t.Errorf("should accept %q", d)
+		}
+	}
+	for _, d := range bad {
+		if selfHostedDomainRegex.MatchString(d) {
 			t.Errorf("should reject %q", d)
 		}
 	}