diff --git a/Makefile b/Makefile
index df637cf68..26993ee1c 100644
--- a/Makefile
+++ b/Makefile
@@ -621,7 +621,7 @@ OPTIONS_OBJS += src/quic_conn.o src/mux_quic.o src/h3.o src/xprt_quic.o    \
                 src/cbuf.o src/quic_cc.o src/quic_cc_nocc.o src/quic_ack.o \
                 src/quic_trace.o src/quic_cli.o src/quic_ssl.o             \
                 src/quic_rx.o src/quic_tx.o src/quic_cid.o src/quic_retry.o\
-                src/quic_retransmit.o
+                src/quic_retransmit.o src/quic_fctl.o
 endif
 
 ifneq ($(USE_QUIC_OPENSSL_COMPAT),)
diff --git a/include/haproxy/quic_fctl-t.h b/include/haproxy/quic_fctl-t.h
new file mode 100644
index 000000000..933161954
--- /dev/null
+++ b/include/haproxy/quic_fctl-t.h
@@ -0,0 +1,15 @@
+#ifndef _HAPROXY_QUIC_FCTL_T_H
+#define _HAPROXY_QUIC_FCTL_T_H
+
+#include <stdint.h>
+
+struct quic_fctl {
+	/* Offset set by peer which must not be exceeded on send. */
+	uint64_t limit;
+	/* Offset which must never exceed limit. */
+	uint64_t off_real;
+	/* Offset which can go beyond limit one time before being blocked. */
+	uint64_t off_soft;
+};
+
+#endif /* _HAPROXY_QUIC_FCTL_T_H */
diff --git a/include/haproxy/quic_fctl.h b/include/haproxy/quic_fctl.h
new file mode 100644
index 000000000..8818372ae
--- /dev/null
+++ b/include/haproxy/quic_fctl.h
@@ -0,0 +1,19 @@
+#ifndef _HAPROXY_QUIC_FCTL_H
+#define _HAPROXY_QUIC_FCTL_H
+
+#include <haproxy/quic_fctl-t.h>
+
+void qfctl_init(struct quic_fctl *fctl, uint64_t limit);
+
+int qfctl_rblocked(const struct quic_fctl *fctl);
+int qfctl_sblocked(const struct quic_fctl *fctl);
+
+int qfctl_set_max(struct quic_fctl *fctl, uint64_t val,
+                  int *unblock_soft, int *unblock_real);
+
+int qfctl_rinc(struct quic_fctl *fctl, uint64_t diff);
+int qfctl_sinc(struct quic_fctl *fctl, uint64_t diff);
+
+uint64_t qfctl_rcap(const struct quic_fctl *fctl);
+
+#endif /* _HAPROXY_QUIC_FCTL_H */
diff --git a/src/quic_fctl.c b/src/quic_fctl.c
new file mode 100644
index 000000000..b797e5517
--- /dev/null
+++ b/src/quic_fctl.c
@@ -0,0 +1,96 @@
+#include <haproxy/quic_fctl.h>
+
+#include <haproxy/api.h>
+
+void qfctl_init(struct quic_fctl *fctl, uint64_t limit)
+{
+	fctl->limit = limit;
+	fctl->off_real = 0;
+	fctl->off_soft = 0;
+}
+
+/* Returns true if real limit is blocked for <fctl> flow control instance.
+ * This happens if it is equal than current max value.
+ */
+int qfctl_rblocked(const struct quic_fctl *fctl)
+{
+	/* Real limit must never be exceeded. */
+	BUG_ON(fctl->off_real > fctl->limit);
+	return fctl->off_real == fctl->limit;
+}
+
+/* Returns true if soft limit is blocked for <fctl> flow control instance.
+ * This happens if it is equal or greater than current max value.
+ */
+int qfctl_sblocked(const struct quic_fctl *fctl)
+{
+	return fctl->off_soft >= fctl->limit;
+}
+
+/* Set a new <val> maximum value for <fctl> flow control instance. If current
+ * offset is already equal or more, the new value is ignored. Additionally,
+ * <unblocked_soft> and <unblocked_real> can be used as output parameters to
+ * detect if the current update result in one or both of these offsets to be
+ * unblocked.
+ *
+ * Returns true if max is incremented else false.
+ */
+int qfctl_set_max(struct quic_fctl *fctl, uint64_t val,
+                  int *out_unblock_soft, int *out_unblock_real)
+{
+	int unblock_soft = 0, unblock_real = 0;
+	int ret = 0;
+
+	if (fctl->limit < val) {
+		if (fctl->off_soft >= fctl->limit && fctl->off_soft < val)
+			unblock_soft = 1;
+		if (fctl->off_real == fctl->limit && fctl->off_real < val)
+			unblock_real = 1;
+
+		fctl->limit = val;
+		ret = 1;
+	}
+
+	if (out_unblock_soft)
+		*out_unblock_soft = unblock_soft;
+	if (out_unblock_real)
+		*out_unblock_real = unblock_real;
+
+	return ret;
+}
+
+/* Increment real offset of <fctl> flow control instance by <diff>. This cannot
+ * exceed <fctl> limit.
+ *
+ * Returns true if limit is reached after increment.
+ */
+int qfctl_rinc(struct quic_fctl *fctl, uint64_t diff)
+{
+	/* Real limit must never be exceeded. */
+	BUG_ON(fctl->off_real + diff > fctl->limit);
+	fctl->off_real += diff;
+
+	return fctl->off_real == fctl->limit;
+}
+
+/* Increment soft offset of <fctl> flow control instance by <diff>. This cannot
+ * be done if <fctl> limit was already reached.
+ *
+ * Returns true if limit is reached after increment.
+ */
+int qfctl_sinc(struct quic_fctl *fctl, uint64_t diff)
+{
+	/* Soft limit must not be incremented if already in excess. */
+	BUG_ON(qfctl_sblocked(fctl));
+	fctl->off_soft += diff;
+
+	return fctl->off_soft >= fctl->limit;
+}
+
+/* Return the remaining offset before reaching <fctl> limit. */
+uint64_t qfctl_rcap(const struct quic_fctl *fctl)
+{
+	/* Real limit must never be exceeded. */
+	BUG_ON(fctl->off_real > fctl->limit);
+	return fctl->limit - fctl->off_real;
+}