diff --git a/CHANGES.md b/CHANGES.md
index cae604adac..5996b7bcdf 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,33 @@
+# Synapse 1.149.0rc1 (2026-03-03)
+
+## Features
+
+- Add experimental support for [MSC4388: Secure out-of-band channel for sign in with QR](https://github.com/matrix-org/matrix-spec-proposals/pull/4388). ([\#19127](https://github.com/element-hq/synapse/issues/19127))
+- Add stable support for [MSC4380](https://github.com/matrix-org/matrix-spec-proposals/pull/4380) invite blocking. ([\#19431](https://github.com/element-hq/synapse/issues/19431))
+
+## Bugfixes
+
+- Fix the 'Login as a user' Admin API not checking if the user exists before issuing an access token. ([\#18518](https://github.com/element-hq/synapse/issues/18518))
+- Fix `/sync` missing membership event in `state_after` (experimental [MSC4222](https://github.com/matrix-org/matrix-spec-proposals/pull/4222) implementation) in some scenarios. ([\#19460](https://github.com/element-hq/synapse/issues/19460))
+
+## Internal Changes
+
+- Add log to explain when and why we freeze objects in the garbage collector. ([\#19440](https://github.com/element-hq/synapse/issues/19440))
+- Better instrument `JoinRoomAliasServlet` with tracing. ([\#19461](https://github.com/element-hq/synapse/issues/19461))
+- Fix Complement CI not running against the code from our PRs. ([\#19475](https://github.com/element-hq/synapse/issues/19475))
+- Log `docker system info` in CI so we have a plain record of how GitHub runners evolve over time. ([\#19480](https://github.com/element-hq/synapse/issues/19480))
+- Rename the `test_disconnect` test helper so that pytest doesn't see it as a test. ([\#19486](https://github.com/element-hq/synapse/issues/19486))
+- Add a log line when we delete devices. Contributed by @bradtgmurray @ Beeper. ([\#19496](https://github.com/element-hq/synapse/issues/19496))
+- Pre-allocate the buffer based on the expected `Content-Length` with the Rust HTTP client. ([\#19498](https://github.com/element-hq/synapse/issues/19498))
+- Cancel long-running sync requests if the client has gone away. ([\#19499](https://github.com/element-hq/synapse/issues/19499))
+- Try and reduce reactor tick times when under heavy load. ([\#19507](https://github.com/element-hq/synapse/issues/19507))
+- Simplify Rust HTTP client response streaming and limiting. ([\#19510](https://github.com/element-hq/synapse/issues/19510))
+- Replace deprecated collection import locations with current locations. ([\#19515](https://github.com/element-hq/synapse/issues/19515))
+- Bump most locked Python dependencies to their latest versions. ([\#19519](https://github.com/element-hq/synapse/issues/19519))
+
+
+
+
 # Synapse 1.148.0 (2026-02-24)
 
 No significant changes since 1.148.0rc1.
diff --git a/changelog.d/18518.bugfix b/changelog.d/18518.bugfix
deleted file mode 100644
index 959528d7c8..0000000000
--- a/changelog.d/18518.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix the 'Login as a user' Admin API not checking if the user exists before issuing an access token.
\ No newline at end of file
diff --git a/changelog.d/19127.feature b/changelog.d/19127.feature
deleted file mode 100644
index 7dc3a49f36..0000000000
--- a/changelog.d/19127.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add experimental support for [MSC4388: Secure out-of-band channel for sign in with QR](https://github.com/matrix-org/matrix-spec-proposals/pull/4388).
diff --git a/changelog.d/19431.feature b/changelog.d/19431.feature
deleted file mode 100644
index 0076e5221c..0000000000
--- a/changelog.d/19431.feature
+++ /dev/null
@@ -1 +0,0 @@
-Add stable support for [MSC4380](https://github.com/matrix-org/matrix-spec-proposals/pull/4380) invite blocking.
diff --git a/changelog.d/19440.misc b/changelog.d/19440.misc
deleted file mode 100644
index 7777601114..0000000000
--- a/changelog.d/19440.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add log to explain when and why we freeze objects in the garbage collector.
diff --git a/changelog.d/19460.bugfix b/changelog.d/19460.bugfix
deleted file mode 100644
index fe44c2ddf6..0000000000
--- a/changelog.d/19460.bugfix
+++ /dev/null
@@ -1 +0,0 @@
-Fix `/sync` missing membership event in `state_after` (experimental [MSC4222](https://github.com/matrix-org/matrix-spec-proposals/pull/4222) implementation) in some scenarios.
diff --git a/changelog.d/19461.misc b/changelog.d/19461.misc
deleted file mode 100644
index 9c444ffe3c..0000000000
--- a/changelog.d/19461.misc
+++ /dev/null
@@ -1 +0,0 @@
-Better instrument `JoinRoomAliasServlet` with tracing.
diff --git a/changelog.d/19475.misc b/changelog.d/19475.misc
deleted file mode 100644
index ea2774dcb1..0000000000
--- a/changelog.d/19475.misc
+++ /dev/null
@@ -1 +0,0 @@
-Fix Complement CI not running against the code from our PRs.
diff --git a/changelog.d/19480.misc b/changelog.d/19480.misc
deleted file mode 100644
index 60abe04962..0000000000
--- a/changelog.d/19480.misc
+++ /dev/null
@@ -1 +0,0 @@
-Log `docker system info` in CI so we have a plain record of how GitHub runners evolve over time.
diff --git a/changelog.d/19486.misc b/changelog.d/19486.misc
deleted file mode 100644
index c0c2fef770..0000000000
--- a/changelog.d/19486.misc
+++ /dev/null
@@ -1 +0,0 @@
-Rename the `test_disconnect` test helper so that pytest doesn't see it as a test.
\ No newline at end of file
diff --git a/changelog.d/19496.misc b/changelog.d/19496.misc
deleted file mode 100644
index 83c5d6987c..0000000000
--- a/changelog.d/19496.misc
+++ /dev/null
@@ -1 +0,0 @@
-Add a log line when we delete devices. Contributed by @bradtgmurray @ Beeper.
diff --git a/changelog.d/19498.misc b/changelog.d/19498.misc
deleted file mode 100644
index 7d048c283d..0000000000
--- a/changelog.d/19498.misc
+++ /dev/null
@@ -1 +0,0 @@
-Pre-allocate the buffer based on the expected `Content-Length` with the Rust HTTP client.
diff --git a/changelog.d/19499.misc b/changelog.d/19499.misc
deleted file mode 100644
index c2641c1e58..0000000000
--- a/changelog.d/19499.misc
+++ /dev/null
@@ -1 +0,0 @@
-Cancel long-running sync requests if the client has gone away.
diff --git a/changelog.d/19507.misc b/changelog.d/19507.misc
deleted file mode 100644
index 5a7ccff988..0000000000
--- a/changelog.d/19507.misc
+++ /dev/null
@@ -1 +0,0 @@
-Try and reduce reactor tick times when under heavy load.
diff --git a/changelog.d/19510.misc b/changelog.d/19510.misc
deleted file mode 100644
index cafc26601f..0000000000
--- a/changelog.d/19510.misc
+++ /dev/null
@@ -1 +0,0 @@
-Simplify Rust HTTP client response streaming and limiting.
diff --git a/changelog.d/19515.misc b/changelog.d/19515.misc
deleted file mode 100644
index d33af36406..0000000000
--- a/changelog.d/19515.misc
+++ /dev/null
@@ -1 +0,0 @@
-Replace deprecated collection import locations with current locations.
\ No newline at end of file
diff --git a/changelog.d/19519.misc b/changelog.d/19519.misc
deleted file mode 100644
index 860a5f5130..0000000000
--- a/changelog.d/19519.misc
+++ /dev/null
@@ -1 +0,0 @@
-Bump most locked Python dependencies to their latest versions.
diff --git a/debian/changelog b/debian/changelog
index 31fd948be1..583bb35ad5 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.149.0~rc1) stable; urgency=medium
+
+  * New synapse release 1.149.0rc1.
+
+ -- Synapse Packaging team <packages@matrix.org>  Tue, 03 Mar 2026 14:37:57 +0000
+
 matrix-synapse-py3 (1.148.0) stable; urgency=medium
 
   * New synapse release 1.148.0.
diff --git a/pyproject.toml b/pyproject.toml
index 2d55d3c7a5..9d5e3fec2d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "matrix-synapse"
-version = "1.148.0"
+version = "1.149.0rc1"
 description = "Homeserver for the Matrix decentralised comms protocol"
 readme = "README.rst"
 authors = [
diff --git a/schema/synapse-config.schema.yaml b/schema/synapse-config.schema.yaml
index 31cdb101e2..3a61a4c6fc 100644
--- a/schema/synapse-config.schema.yaml
+++ b/schema/synapse-config.schema.yaml
@@ -1,5 +1,5 @@
 $schema: https://element-hq.github.io/synapse/latest/schema/v1/meta.schema.json
-$id: https://element-hq.github.io/synapse/schema/synapse/v1.148/synapse-config.schema.json
+$id: https://element-hq.github.io/synapse/schema/synapse/v1.149/synapse-config.schema.json
 type: object
 properties:
   modules: