diff --git a/config/example-extras.cfg b/config/example-extras.cfg
index f7deeb61..fc28000e 100644
--- a/config/example-extras.cfg
+++ b/config/example-extras.cfg
@@ -1106,6 +1106,10 @@
 #stealthchop_threshold: 0
 #   See the tmc2208 section above for the definition of these
 #   parameters.
+#uart_address:
+#   The address of the TMC2209 chip for UART messages (an integer
+#   between 0 and 3). This is typically used when multiple TMC2209
+#   chips are connected to the same UART pin. The default is zero.
 #driver_IHOLDDELAY: 8
 #driver_TPOWERDOWN: 20
 #driver_TBL: 2
diff --git a/klippy/extras/tmc2209.py b/klippy/extras/tmc2209.py
index 45072446..5f487122 100644
--- a/klippy/extras/tmc2209.py
+++ b/klippy/extras/tmc2209.py
@@ -58,7 +58,7 @@ class TMC2209:
         # Setup mcu communication
         self.fields = tmc.FieldHelper(Fields, tmc2208.SignedFields,
                                       FieldFormatters)
-        self.mcu_tmc = tmc_uart.MCU_TMC_uart(config, Registers, self.fields)
+        self.mcu_tmc = tmc_uart.MCU_TMC_uart(config, Registers, self.fields, 3)
         # Allow virtual pins to be created
         tmc.TMCVirtualPinHelper(config, self.mcu_tmc)
         # Register commands
diff --git a/klippy/extras/tmc_uart.py b/klippy/extras/tmc_uart.py
index bf6a29cf..8af0be07 100644
--- a/klippy/extras/tmc_uart.py
+++ b/klippy/extras/tmc_uart.py
@@ -77,19 +77,20 @@ class MCU_TMC_uart_bitbang:
             % (self.oid, self.rx_pin, self.pullup, self.tx_pin, bit_ticks))
         self.tmcuart_send_cmd = self.mcu.lookup_command(
             "tmcuart_send oid=%c write=%*s read=%c", cq=self.cmd_queue)
-    def register_instance(self, rx_pin_params, tx_pin_params, select_pins_desc):
+    def register_instance(self, rx_pin_params, tx_pin_params,
+                          select_pins_desc, addr):
         if (rx_pin_params['pin'] != self.rx_pin
             or tx_pin_params['pin'] != self.tx_pin
             or (select_pins_desc is None) != (self.analog_mux is None)):
             raise self.mcu.get_printer().config_error(
-                "Shared TMC uart must use identical pins")
+                "Shared TMC uarts must use the same pins")
         instance_id = None
         if self.analog_mux is not None:
             instance_id = self.analog_mux.get_instance_id(select_pins_desc)
-        if instance_id in self.instances:
+        if (instance_id, addr) in self.instances:
             raise self.mcu.get_printer().config_error(
-                "Each TMC uart must have unique select pins polarity")
-        self.instances[instance_id] = True
+                "Shared TMC uarts need unique address or select_pins polarity")
+        self.instances[(instance_id, addr)] = True
         return instance_id
     def _calc_crc8(self, data):
         # Generate a CRC8-ATM value for a bytearray
@@ -156,13 +157,13 @@ class MCU_TMC_uart_bitbang:
             minclock = self.mcu.print_time_to_clock(print_time)
         if self.analog_mux is not None:
             self.analog_mux.activate(instance_id)
-        msg = self._encode_write(0xf5, 0x00, reg | 0x80, val)
+        msg = self._encode_write(0xf5, addr, reg | 0x80, val)
         self.tmcuart_send_cmd.send_with_response(
             [self.oid, msg, 0], 'tmcuart_response', self.oid,
             minclock=minclock)
 
 # Lookup a (possibly shared) tmc uart
-def lookup_tmc_uart_bitbang(config):
+def lookup_tmc_uart_bitbang(config, max_addr):
     ppins = config.get_printer().lookup_object("pins")
     rx_pin_params = ppins.lookup_pin(
         config.get('uart_pin'), can_pullup=True, share_type="tmc_uart_rx")
@@ -174,25 +175,26 @@ def lookup_tmc_uart_bitbang(config):
     if rx_pin_params['chip'] is not tx_pin_params['chip']:
         raise ppins.error("TMC uart rx and tx pins must be on the same mcu")
     select_pins_desc = config.get('select_pins', None)
+    addr = config.getint('uart_address', 0, maxval=max_addr)
     mcu_uart = rx_pin_params.get('class')
     if mcu_uart is None:
         mcu_uart = MCU_TMC_uart_bitbang(rx_pin_params, tx_pin_params,
                                         select_pins_desc)
         rx_pin_params['class'] = mcu_uart
     instance_id = mcu_uart.register_instance(rx_pin_params, tx_pin_params,
-                                             select_pins_desc)
-    return instance_id, mcu_uart
+                                             select_pins_desc, addr)
+    return instance_id, addr, mcu_uart
 
 # Helper code for communicating via TMC uart
 class MCU_TMC_uart:
-    def __init__(self, config, name_to_reg, fields):
+    def __init__(self, config, name_to_reg, fields, max_addr=0):
         self.printer = config.get_printer()
         self.name = config.get_name().split()[-1]
         self.name_to_reg = name_to_reg
         self.fields = fields
         self.ifcnt = None
-        self.addr = 0
-        self.instance_id, self.mcu_uart = lookup_tmc_uart_bitbang(config)
+        self.instance_id, self.addr, self.mcu_uart = lookup_tmc_uart_bitbang(
+            config, max_addr)
         self.mutex = self.mcu_uart.mutex
     def get_fields(self):
         return self.fields