diff --git a/custom_components/jev/conversation.py b/custom_components/jev/conversation.py
index 359094b..e37818d 100644
--- a/custom_components/jev/conversation.py
+++ b/custom_components/jev/conversation.py
@@ -53,6 +53,7 @@
 from .coordinator import JevRuntimeData
 from .entity import build_device_info
 from .interpret import build_questions, interpret
+from .payload import payload_bytes
 from .snapshot import async_snapshot
 
 _LOGGER = logging.getLogger(__name__)
@@ -72,7 +73,9 @@
     "already_on": "{name} is already on.",
     "already_off": "{name} is already off.",
     "query_not_found": "I could not find that.",
-    "budget_spent": "The daily token budget is spent, so I cannot do that today.",
+    "budget_spent": (
+        "Not enough of the daily token budget is left for that, so I cannot do it today."
+    ),
     "auth_failed": "TypeSafe rejected the API key. Check it in the Jev settings.",
     "unavailable": "TypeSafe did not answer. Try again in a moment.",
 }
@@ -154,14 +157,7 @@ async def _async_handle_message(
     ) -> conversation.ConversationResult:
         runtime: JevRuntimeData = self._entry.runtime_data
 
-        # The budget covers voice as well as sensors, because a satellite that
-        # mishears a wake word all night is exactly the runaway it exists to stop.
         runtime.usage.roll_over(dt_util.now().date())
-        if runtime.usage.would_exceed():
-            return await self._fall_back(
-                user_input, "the daily token budget is spent", "budget_spent"
-            )
-
         snapshot = async_snapshot(self.hass, MAX_CONVERSATION_ENTITIES)
         if not snapshot.entities:
             return await self._fall_back(user_input, "no entities are exposed to Assist")
@@ -169,8 +165,23 @@ async def _async_handle_message(
         questions = build_questions(user_input.text, snapshot, MAX_CONVERSATION_ENTITIES)
         state = snapshot.as_state() | {"command": user_input.text}
 
+        # The budget covers voice as well as sensors, because a satellite that
+        # mishears a wake word all night is exactly the runaway it exists to stop.
+        # The check is on this command's estimate, the same as a context's, so the
+        # last command of the day cannot take the total past the budget.
+        request_bytes = payload_bytes(state, questions, runtime.model)
+        estimate = runtime.usage.estimate_tokens(request_bytes)
+        if runtime.usage.would_exceed_with(estimate):
+            return await self._fall_back(
+                user_input,
+                f"the daily token budget has {runtime.usage.remaining()} tokens left "
+                f"and this command needs about {estimate}",
+                "budget_spent",
+            )
+
         try:
-            response = await runtime.client.ask(state, questions)
+            with runtime.usage.reservation(estimate):
+                response = await runtime.client.ask(state, questions)
         except JevAuthError as err:
             _LOGGER.error("TypeSafe rejected the API key: %s", err)
             self._entry.async_start_reauth(self.hass)
@@ -183,7 +194,7 @@ async def _async_handle_message(
                 user_input, f"TypeSafe did not answer: {err}", "unavailable"
             )
 
-        runtime.usage.record(response.usage.input_tokens)
+        runtime.usage.record(response.usage.input_tokens, request_bytes)
         runtime.model_version = response.model or runtime.model_version
         runtime.usage.notify()
 
@@ -267,7 +278,14 @@ async def _fall_back(
         agent = self._fallback_agent
         _LOGGER.debug("falling back to %s because %s", agent or "nobody", why)
         if agent is None:
-            return await self._speak(user_input, line)
+            # An error, as the default agent answers one. A satellite and the Assist
+            # dialog treat an action_done reply as a command that went through.
+            code = (
+                ha_intent.IntentResponseErrorCode.NO_INTENT_MATCH
+                if line == "not_understood"
+                else ha_intent.IntentResponseErrorCode.FAILED_TO_HANDLE
+            )
+            return await self._speak(user_input, line, error=code)
         result = await conversation.async_converse(
             self.hass,
             user_input.text,
@@ -316,13 +334,17 @@ async def _speak(
         self,
         user_input: conversation.ConversationInput,
         key: str,
+        error: ha_intent.IntentResponseErrorCode | None = None,
         **placeholders: str,
     ) -> conversation.ConversationResult:
         """Say one of our own lines, with its placeholders filled in."""
         language = user_input.language or self.hass.config.language
-        text = (await self._lines(language))[key]
+        text = (await self._lines(language))[key].format(**placeholders)
         response = ha_intent.IntentResponse(language=user_input.language)
-        response.async_set_speech(text.format(**placeholders))
+        if error is None:
+            response.async_set_speech(text)
+        else:
+            response.async_set_error(error, text)
         return conversation.ConversationResult(
             response=response, conversation_id=user_input.conversation_id
         )
diff --git a/custom_components/jev/strings.json b/custom_components/jev/strings.json
index 54cf0a1..1502dc0 100644
--- a/custom_components/jev/strings.json
+++ b/custom_components/jev/strings.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "The API answered, but not to the question that was asked.",
     "preview_template_error": "The template does not render: {reason}",
     "query_not_found": "I could not find that.",
-    "budget_spent": "The daily token budget is spent, so I cannot do that today.",
+    "budget_spent": "Not enough of the daily token budget is left for that, so I cannot do it today.",
     "auth_failed": "TypeSafe rejected the API key. Check it in the Jev settings.",
     "unavailable": "TypeSafe did not answer. Try again in a moment.",
     "preview_over_budget": "The daily token budget is spent, so there is no trial answer. The question still saves.",
diff --git a/custom_components/jev/translations/cs.json b/custom_components/jev/translations/cs.json
index dd03fe5..b9261e9 100644
--- a/custom_components/jev/translations/cs.json
+++ b/custom_components/jev/translations/cs.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "API odpovědělo, ale ne na otázku, která byla položena.",
     "preview_template_error": "Šablona se nevykreslí: {reason}",
     "query_not_found": "To jsem nenašel.",
-    "budget_spent": "Denní rozpočet tokenů je vyčerpán, takže to dnes udělat nemohu.",
+    "budget_spent": "Z denního rozpočtu tokenů na to nezbývá dost, takže to dnes udělat nemohu.",
     "auth_failed": "TypeSafe odmítl klíč API. Zkontrolujte ho v nastavení Jev.",
     "unavailable": "TypeSafe neodpověděl. Zkuste to za chvíli znovu.",
     "preview_over_budget": "Denní rozpočet tokenů je vyčerpán, takže zkušební odpověď není. Otázka se přesto uloží.",
diff --git a/custom_components/jev/translations/da.json b/custom_components/jev/translations/da.json
index bbdea05..162a8fb 100644
--- a/custom_components/jev/translations/da.json
+++ b/custom_components/jev/translations/da.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "API'en svarede, men ikke på det spørgsmål, der blev stillet.",
     "preview_template_error": "Skabelonen kan ikke gengives: {reason}",
     "query_not_found": "Det kunne jeg ikke finde.",
-    "budget_spent": "Det daglige tokenbudget er brugt, så det kan jeg ikke gøre i dag.",
+    "budget_spent": "Der er ikke nok tilbage af det daglige tokenbudget til det, så det kan jeg ikke gøre i dag.",
     "auth_failed": "TypeSafe afviste API-nøglen. Tjek den i indstillingerne for Jev.",
     "unavailable": "TypeSafe svarede ikke. Prøv igen om et øjeblik.",
     "preview_over_budget": "Det daglige token-budget er brugt op, så der er intet prøvesvar. Spørgsmålet bliver gemt alligevel.",
diff --git a/custom_components/jev/translations/de.json b/custom_components/jev/translations/de.json
index 89c7dbc..69fbe6c 100644
--- a/custom_components/jev/translations/de.json
+++ b/custom_components/jev/translations/de.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "Die API hat geantwortet, aber nicht auf die gestellte Frage.",
     "preview_template_error": "Die Vorlage lässt sich nicht rendern: {reason}",
     "query_not_found": "Das konnte ich nicht finden.",
-    "budget_spent": "Das tägliche Token-Budget ist aufgebraucht, deshalb kann ich das heute nicht tun.",
+    "budget_spent": "Vom täglichen Token-Budget ist dafür nicht mehr genug übrig, deshalb kann ich das heute nicht tun.",
     "auth_failed": "TypeSafe hat den API-Schlüssel abgelehnt. Prüfe ihn in den Jev-Einstellungen.",
     "unavailable": "TypeSafe hat nicht geantwortet. Versuche es gleich noch einmal.",
     "preview_over_budget": "Das Tagesbudget für Tokens ist aufgebraucht, es gibt also keine Probeantwort. Die Frage wird trotzdem gespeichert.",
diff --git a/custom_components/jev/translations/en.json b/custom_components/jev/translations/en.json
index 54cf0a1..1502dc0 100644
--- a/custom_components/jev/translations/en.json
+++ b/custom_components/jev/translations/en.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "The API answered, but not to the question that was asked.",
     "preview_template_error": "The template does not render: {reason}",
     "query_not_found": "I could not find that.",
-    "budget_spent": "The daily token budget is spent, so I cannot do that today.",
+    "budget_spent": "Not enough of the daily token budget is left for that, so I cannot do it today.",
     "auth_failed": "TypeSafe rejected the API key. Check it in the Jev settings.",
     "unavailable": "TypeSafe did not answer. Try again in a moment.",
     "preview_over_budget": "The daily token budget is spent, so there is no trial answer. The question still saves.",
diff --git a/custom_components/jev/translations/es.json b/custom_components/jev/translations/es.json
index a3e9da7..731deeb 100644
--- a/custom_components/jev/translations/es.json
+++ b/custom_components/jev/translations/es.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "La API ha respondido, pero no a la pregunta que se le hizo.",
     "preview_template_error": "La plantilla no se procesa: {reason}",
     "query_not_found": "No he podido encontrarlo.",
-    "budget_spent": "El presupuesto diario de tokens se ha agotado, así que hoy no puedo hacerlo.",
+    "budget_spent": "No queda suficiente presupuesto diario de tokens para eso, así que hoy no puedo hacerlo.",
     "auth_failed": "TypeSafe rechazó la clave de API. Revísala en los ajustes de Jev.",
     "unavailable": "TypeSafe no respondió. Inténtalo de nuevo en un momento.",
     "preview_over_budget": "El presupuesto diario de tokens está agotado, así que no hay respuesta de prueba. La pregunta sí se guarda.",
diff --git a/custom_components/jev/translations/fr.json b/custom_components/jev/translations/fr.json
index d05d12e..96b7c78 100644
--- a/custom_components/jev/translations/fr.json
+++ b/custom_components/jev/translations/fr.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "L'API a répondu, mais pas à la question qui a été posée.",
     "preview_template_error": "Le rendu du modèle échoue : {reason}",
     "query_not_found": "Je n'ai pas trouvé cela.",
-    "budget_spent": "Le budget quotidien de jetons est épuisé, je ne peux donc pas le faire aujourd'hui.",
+    "budget_spent": "Il ne reste pas assez de budget quotidien de jetons pour cela, je ne peux donc pas le faire aujourd'hui.",
     "auth_failed": "TypeSafe a refusé la clé API. Vérifiez-la dans les paramètres de Jev.",
     "unavailable": "TypeSafe n'a pas répondu. Réessayez dans un instant.",
     "preview_over_budget": "Le budget quotidien de jetons est épuisé, il n'y a donc pas de réponse d'essai. La question est quand même enregistrée.",
diff --git a/custom_components/jev/translations/it.json b/custom_components/jev/translations/it.json
index 9d88f65..dbbc17d 100644
--- a/custom_components/jev/translations/it.json
+++ b/custom_components/jev/translations/it.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "L'API ha risposto, ma non alla domanda che è stata posta.",
     "preview_template_error": "Il template non si elabora: {reason}",
     "query_not_found": "Non sono riuscito a trovarlo.",
-    "budget_spent": "Il budget giornaliero di token è esaurito, quindi oggi non posso farlo.",
+    "budget_spent": "Non resta abbastanza budget giornaliero di token per questo, quindi oggi non posso farlo.",
     "auth_failed": "TypeSafe ha rifiutato la chiave API. Controllala nelle impostazioni di Jev.",
     "unavailable": "TypeSafe non ha risposto. Riprova tra un momento.",
     "preview_over_budget": "Il budget giornaliero di token è esaurito, quindi non c'è una risposta di prova. La domanda viene comunque salvata.",
diff --git a/custom_components/jev/translations/nl.json b/custom_components/jev/translations/nl.json
index 48220fd..3a937ab 100644
--- a/custom_components/jev/translations/nl.json
+++ b/custom_components/jev/translations/nl.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "De API antwoordde, maar niet op de vraag die gesteld is.",
     "preview_template_error": "De template rendert niet: {reason}",
     "query_not_found": "Dat kon ik niet vinden.",
-    "budget_spent": "Het dagelijkse tokenbudget is op, dus dat kan ik vandaag niet doen.",
+    "budget_spent": "Er is niet genoeg over van het dagelijkse tokenbudget, dus dat kan ik vandaag niet doen.",
     "auth_failed": "TypeSafe heeft de API-sleutel geweigerd. Controleer hem in de instellingen van Jev.",
     "unavailable": "TypeSafe gaf geen antwoord. Probeer het zo nog eens.",
     "preview_over_budget": "Het daglimiet voor tokens is op, dus er is geen proefantwoord. De vraag wordt wel opgeslagen.",
diff --git a/custom_components/jev/translations/pl.json b/custom_components/jev/translations/pl.json
index a5765eb..2ad1ed1 100644
--- a/custom_components/jev/translations/pl.json
+++ b/custom_components/jev/translations/pl.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "API odpowiedziało, ale nie na zadane pytanie.",
     "preview_template_error": "Szablon się nie renderuje: {reason}",
     "query_not_found": "Nie udało mi się tego znaleźć.",
-    "budget_spent": "Dzienny budżet tokenów się wyczerpał, więc dziś nie mogę tego zrobić.",
+    "budget_spent": "W dziennym budżecie tokenów nie zostało na to dość, więc dziś nie mogę tego zrobić.",
     "auth_failed": "TypeSafe odrzucił klucz API. Sprawdź go w ustawieniach Jev.",
     "unavailable": "TypeSafe nie odpowiedział. Spróbuj ponownie za chwilę.",
     "preview_over_budget": "Dzienny limit tokenów jest wyczerpany, więc nie ma próbnej odpowiedzi. Pytanie i tak zostanie zapisane.",
diff --git a/custom_components/jev/translations/pt-BR.json b/custom_components/jev/translations/pt-BR.json
index 22b1c26..dab4a50 100644
--- a/custom_components/jev/translations/pt-BR.json
+++ b/custom_components/jev/translations/pt-BR.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "A API respondeu, mas não à pergunta que foi feita.",
     "preview_template_error": "O template não é renderizado: {reason}",
     "query_not_found": "Não consegui encontrar isso.",
-    "budget_spent": "O orçamento diário de tokens acabou, então não posso fazer isso hoje.",
+    "budget_spent": "Não resta orçamento diário de tokens suficiente para isso, então não posso fazer isso hoje.",
     "auth_failed": "A TypeSafe rejeitou a chave de API. Verifique-a nas configurações do Jev.",
     "unavailable": "A TypeSafe não respondeu. Tente novamente em instantes.",
     "preview_over_budget": "O orçamento diário de tokens acabou, então não há resposta de teste. A pergunta ainda é salva.",
diff --git a/custom_components/jev/translations/ru.json b/custom_components/jev/translations/ru.json
index 1f50471..9742937 100644
--- a/custom_components/jev/translations/ru.json
+++ b/custom_components/jev/translations/ru.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "API ответил, но не на тот вопрос, который был задан.",
     "preview_template_error": "Шаблон не обрабатывается: {reason}",
     "query_not_found": "Мне не удалось это найти.",
-    "budget_spent": "Дневной бюджет токенов исчерпан, поэтому сегодня я не могу это сделать.",
+    "budget_spent": "В дневном бюджете токенов на это не хватает, поэтому сегодня я не могу это сделать.",
     "auth_failed": "TypeSafe отклонил ключ API. Проверьте его в настройках Jev.",
     "unavailable": "TypeSafe не ответил. Попробуйте ещё раз чуть позже.",
     "preview_over_budget": "Дневной бюджет токенов исчерпан, поэтому пробного ответа нет. Вопрос всё равно сохраняется.",
diff --git a/custom_components/jev/translations/sv.json b/custom_components/jev/translations/sv.json
index d49d5b2..5f41075 100644
--- a/custom_components/jev/translations/sv.json
+++ b/custom_components/jev/translations/sv.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "API:et svarade, men inte på frågan som ställdes.",
     "preview_template_error": "Mallen renderas inte: {reason}",
     "query_not_found": "Det kunde jag inte hitta.",
-    "budget_spent": "Den dagliga tokenbudgeten är slut, så det kan jag inte göra i dag.",
+    "budget_spent": "Det finns inte tillräckligt kvar av den dagliga tokenbudgeten för det, så det kan jag inte göra i dag.",
     "auth_failed": "TypeSafe avvisade API-nyckeln. Kontrollera den i inställningarna för Jev.",
     "unavailable": "TypeSafe svarade inte. Försök igen om en stund.",
     "preview_over_budget": "Den dagliga budgeten för token är slut, så det finns inget provsvar. Frågan sparas ändå.",
diff --git a/custom_components/jev/translations/zh-Hans.json b/custom_components/jev/translations/zh-Hans.json
index 85f813c..1490080 100644
--- a/custom_components/jev/translations/zh-Hans.json
+++ b/custom_components/jev/translations/zh-Hans.json
@@ -364,7 +364,7 @@
     "preview_mismatched": "API 作出了回答，但回答的不是所提的那个问题。",
     "preview_template_error": "模板无法渲染：{reason}",
     "query_not_found": "我找不到那个。",
-    "budget_spent": "今天的令牌预算已用完，所以今天无法执行。",
+    "budget_spent": "今天剩余的令牌预算不足，所以无法执行。",
     "auth_failed": "TypeSafe 拒绝了 API 密钥。请在 Jev 设置中检查。",
     "unavailable": "TypeSafe 没有响应。请稍后再试。",
     "preview_over_budget": "每日令牌预算已用完，因此没有试答结果。问题仍会保存。",
diff --git a/tests/test_conversation.py b/tests/test_conversation.py
index a684f01..99302b2 100644
--- a/tests/test_conversation.py
+++ b/tests/test_conversation.py
@@ -15,8 +15,9 @@
 from homeassistant.core import Context, ServiceCall
 from homeassistant.helpers import area_registry as ar
 from homeassistant.helpers import entity_registry as er
+from homeassistant.helpers import intent as ha_intent
 from homeassistant.setup import async_setup_component
-from jevclient import ChoiceAnswer, NoulAnswer
+from jevclient import ChoiceAnswer, NoulAnswer, Usage
 
 from custom_components.jev.const import (
     CONF_ALLOW_WHOLE_HOME,
@@ -26,6 +27,7 @@
 )
 from custom_components.jev.conversation import _render_state_answer
 from custom_components.jev.interpret import find_brightness
+from custom_components.jev.payload import payload_bytes
 
 from .conftest import PROBE_TOKENS, build_response
 
@@ -197,6 +199,7 @@ async def test_a_compound_command_acts_on_nothing(hass, house, mock_client):
 
     assert calls == []
     assert "did not understand" in result.response.speech["plain"]["speech"]
+    assert result.response.error_code is ha_intent.IntentResponseErrorCode.NO_INTENT_MATCH
 
 
 async def test_low_confidence_acts_on_nothing(hass, house, mock_client):
@@ -341,7 +344,45 @@ async def test_a_spent_budget_stops_voice_too(hass, house, mock_client):
 
     assert mock_client.ask.await_count == 0
     assert calls == []
-    assert "budget is spent" in result.response.speech["plain"]["speech"]
+    assert "budget is left" in result.response.speech["plain"]["speech"]
+    assert result.response.response_type is ha_intent.IntentResponseType.ERROR
+
+
+async def test_a_command_that_would_pass_the_budget_is_not_sent(hass, house, mock_client):
+    # One token short of the budget. would_exceed() says there is room, and on
+    # 1.15 the command went through and ended the day about 1,000 tokens over.
+    hass.config_entries.async_update_entry(house, options={"daily_token_budget": 1000})
+    await hass.async_block_till_done()
+    house.runtime_data.usage.input_tokens = 999
+    mock_client.ask.reset_mock()
+
+    calls = []
+    hass.services.async_register("light", "turn_on", lambda call: calls.append(call))
+    result = await converse(hass, "kitchen light on")
+    await hass.async_block_till_done()
+
+    assert mock_client.ask.await_count == 0
+    assert calls == []
+    assert "budget is left" in result.response.speech["plain"]["speech"]
+    assert result.response.response_type is ha_intent.IntentResponseType.ERROR
+
+
+async def test_a_voice_command_teaches_the_estimate(hass, house, mock_client):
+    # The estimate reads bytes per token from the last call it could measure. A
+    # voice command that did not report its size left the estimate on whatever
+    # the last context taught it, which is a different shape of request.
+    mock_client.ask.return_value = replace(
+        build_response(**answer_set()), usage=Usage(input_tokens=1371, output_tokens=42)
+    )
+    usage = house.runtime_data.usage
+
+    with patch.object(usage, "record", wraps=usage.record) as record:
+        await converse(hass, "kitchen light on")
+        await hass.async_block_till_done()
+
+    sent_state, sent_questions = mock_client.ask.await_args.args
+    sent = payload_bytes(sent_state, sent_questions, house.runtime_data.model)
+    record.assert_called_once_with(1371, sent)
 
 
 async def test_a_rejected_key_is_said_out_loud(hass, house, mock_client):