diff --git a/modules/mesh-vault/cmd/mesh-vault/licencebindings.go b/modules/mesh-vault/cmd/mesh-vault/licencebindings.go
index bb85f20a5..f852d9e63 100644
--- a/modules/mesh-vault/cmd/mesh-vault/licencebindings.go
+++ b/modules/mesh-vault/cmd/mesh-vault/licencebindings.go
@@ -45,6 +45,12 @@ type LicenceBindings struct {
 	Delete func(consumer string) error
 	Keys   func() ([]string, error)
 	Log    func(string, ...any)
+	// WrittenAt is when the bus wrote a consumer's key, so a first view keeps a key an event wrote after it was asked
+	// (B43); nil writes no time, and every key a first view does not name goes.
+	WrittenAt func(consumer string) (time.Time, error)
+	// Answered is whether the first view of the bindings has been answered since the vault started; until it has, an
+	// access token is refused, saying why (B31). Nil is a vault that keeps no first view (its tests).
+	Answered func() bool
 }
 
 // busLicenceBindings is the state on the bus.
@@ -63,6 +69,14 @@ func busLicenceBindings() LicenceBindings {
 		Delete: func(consumer string) error { return st.Delete(consumer) },
 		Keys:   st.Keys,
 		Log:    say,
+		WrittenAt: func(consumer string) (time.Time, error) {
+			e, err := st.Get(consumer)
+			if err != nil || e == nil {
+				return time.Time{}, err
+			}
+			return e.At, nil
+		},
+		Answered: func() bool { return licenceBindingsView != nil && !licenceBindingsView.Status().Answered.IsZero() },
 	}
 }
 
@@ -111,9 +125,10 @@ func (lb LicenceBindings) Heard(body []byte) error {
 	return lb.keep(e.Consumer, LicenceBinding{Licence: e.Licence, Key: e.Key, Generation: e.Generation})
 }
 
-// FirstView takes the manager's answer to `bindings`, by consumer: every binding it names is kept, and every key the
-// state holds for a consumer it does not name is deleted, since that consumer was released.
-func (lb LicenceBindings) FirstView(values map[string]json.RawMessage) error {
+// FirstView takes the manager's answer to `bindings`, asked at asked, by consumer: every binding it names is kept, and
+// every key the state holds for a consumer it does not name is deleted, since that consumer was released, unless an
+// event wrote that key after the view was asked (B43): the view does not know that move yet.
+func (lb LicenceBindings) FirstView(values map[string]json.RawMessage, asked time.Time) error {
 	var errs []error
 	for consumer, raw := range values {
 		var b LicenceBinding
@@ -128,9 +143,20 @@ func (lb LicenceBindings) FirstView(values map[string]json.RawMessage) error {
 		return errors.Join(append(errs, err)...)
 	}
 	for _, consumer := range held {
-		if _, named := values[consumer]; !named {
-			errs = append(errs, lb.Delete(consumer))
+		if _, named := values[consumer]; named {
+			continue
 		}
+		if lb.WrittenAt != nil && !asked.IsZero() {
+			at, err := lb.WrittenAt(consumer)
+			if err != nil {
+				errs = append(errs, err)
+				continue
+			}
+			if at.After(asked) {
+				continue // written by an event after the view was asked (B43)
+			}
+		}
+		errs = append(errs, lb.Delete(consumer))
 	}
 	return errors.Join(errs...)
 }
@@ -192,7 +218,7 @@ func newLicenceBindingsView(ask func(subject string, body any) (json.RawMessage,
 				return
 			}
 			values := f.Values()
-			if err := lb.FirstView(values); err != nil {
+			if err := lb.FirstView(values, s.Asked); err != nil {
 				say("the licence bindings of the first view are not all kept: %v", err)
 				return
 			}
@@ -256,6 +282,9 @@ func (v *Vault) licenceRefusal(caller, name string) (bool, string) {
 	if v.LicenceBindings == nil {
 		return true, "the vault keeps no licence bindings, so no binding names the licence " + key
 	}
+	if v.LicenceBindings.Answered != nil && !v.LicenceBindings.Answered() {
+		return true, "the vault's first view of the licence bindings has not been answered since it started, so it does not yet know which machine a binding names; it asks the licence manager until it answers (B31)"
+	}
 	consumers, err := v.LicenceBindings.Keys()
 	if err != nil {
 		return true, "the licence bindings cannot be read: " + err.Error()
diff --git a/modules/mesh-vault/cmd/mesh-vault/licencebindings_test.go b/modules/mesh-vault/cmd/mesh-vault/licencebindings_test.go
index a9858b11b..1297538ce 100644
--- a/modules/mesh-vault/cmd/mesh-vault/licencebindings_test.go
+++ b/modules/mesh-vault/cmd/mesh-vault/licencebindings_test.go
@@ -8,6 +8,7 @@ import (
 	"slices"
 	"sort"
 	"testing"
+	"time"
 
 	"git.novox.be/novox/mesh-sdk/go/views"
 )
@@ -85,7 +86,7 @@ func TestTheFirstViewOfTheLicenceBindingsIsKept(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if err := lb.FirstView(a.Values); err != nil {
+	if err := lb.FirstView(a.Values, time.Time{}); err != nil {
 		t.Fatal(err)
 	}
 	want := map[string]LicenceBinding{"laptop": {Licence: "acct-1@example.org", Key: "acct-1_at_example.org", Generation: 1013},
@@ -98,10 +99,28 @@ func TestTheFirstViewOfTheLicenceBindingsIsKept(t *testing.T) {
 	}
 	lb.Put = func(string, LicenceBinding) error { return errors.New("the bucket is full") }
 	held["laptop"] = LicenceBinding{Licence: "api", Key: "api", Generation: 1}
-	if err := lb.FirstView(a.Values); err == nil {
+	if err := lb.FirstView(a.Values, time.Time{}); err == nil {
 		t.Fatal("a first view not kept was not said")
 	}
 
+	// B43: a key an event wrote after the view was asked is kept though the view does not name it; one written before
+	// the ask and not named goes.
+	lb, held = memLicenceBindings()
+	asked := time.Date(2026, 11, 12, 1, 0, 0, 0, time.UTC)
+	written := map[string]time.Time{"late": asked.Add(time.Second), "gone": asked.Add(-time.Second)}
+	lb.WrittenAt = func(c string) (time.Time, error) { return written[c], nil }
+	held["late"] = LicenceBinding{Licence: "api", Key: "api", Generation: 2000}
+	held["gone"] = LicenceBinding{Licence: "api", Key: "api", Generation: 9}
+	if err := lb.FirstView(a.Values, asked); err != nil {
+		t.Fatal(err)
+	}
+	if _, ok := held["late"]; !ok {
+		t.Error("a key an event wrote after the first view was asked was removed by it")
+	}
+	if _, ok := held["gone"]; ok {
+		t.Error("a key written before the first view was asked, which it does not name, was kept")
+	}
+
 	manifest, _ := os.ReadFile("../../module.json")
 	var m struct {
 		Invokes, Consumes []string
diff --git a/modules/mesh-vault/cmd/mesh-vault/licences_test.go b/modules/mesh-vault/cmd/mesh-vault/licences_test.go
index 373ad630a..02f8c3357 100644
--- a/modules/mesh-vault/cmd/mesh-vault/licences_test.go
+++ b/modules/mesh-vault/cmd/mesh-vault/licences_test.go
@@ -73,6 +73,22 @@ func TestATokenIsGivenOnlyToAMachineABindingNames(t *testing.T) {
 		}
 	}
 	access := "licence.jane_at_example.org.access"
+	// B31: until the first view of the bindings is answered, an access token is refused, saying why.
+	answered := false
+	lb.Answered = func() bool { return answered }
+	if err := lb.Heard([]byte(`{"consumer":"g14","licence":"jane","key":"jane_at_example.org","generation":1}`)); err != nil {
+		t.Fatal(err)
+	}
+	if _, _, err := asks(v, "g14.node-tools", access); err == nil || !strings.Contains(err.Error(), "first view of the licence bindings has not been answered") {
+		t.Fatalf("a token was handed before the first view was answered: %v", err)
+	}
+	answered = true
+	if _, _, err := asks(v, "g14.node-tools", access); err != nil {
+		t.Fatalf("once the first view is answered the bound machine is refused: %v", err)
+	}
+	if err := lb.Heard([]byte(`{"consumer":"g14","licence":"","key":"","generation":2}`)); err != nil {
+		t.Fatal(err)
+	}
 	if _, _, err := asks(v, "g14.node-tools", access); err == nil || !strings.Contains(err.Error(), "no consumer on g14") {
 		t.Fatalf("a machine no binding names was handed the token: %v", err)
 	}