diff --git a/feeds/ucentral/uspot/files/etc/config/uspot b/feeds/ucentral/uspot/files/etc/config/uspot
index a6e3537fd..8ff7de55a 100644
--- a/feeds/ucentral/uspot/files/etc/config/uspot
+++ b/feeds/ucentral/uspot/files/etc/config/uspot
@@ -18,6 +18,7 @@ config webroot def_captive
 #	option acct_port '1812'		# radius accounting server port
 #	option acct_secret ''		# radius accounting server password
 #	option acct_proxy ''		# radius accounting server proxy
+#	option acct_interval ''		# radius accounting interim interval override
 #	option nasid ''			# radius NAS-Identitifer, UAM '&nasid='
 #	option nasmac ''		# radius Called-Station, UAM '&called='
 #	option mac_format ''		# MAC format specifier: 'aabbccddeeff', 'aa-bb-cc-dd-ee-ff', 'aa:bb:cc:dd:ee:ff' or the equivalent uppercase
diff --git a/feeds/ucentral/uspot/files/usr/share/uspot/accounting.uc b/feeds/ucentral/uspot/files/usr/share/uspot/accounting.uc
index a96f53003..c5cc95459 100755
--- a/feeds/ucentral/uspot/files/usr/share/uspot/accounting.uc
+++ b/feeds/ucentral/uspot/files/usr/share/uspot/accounting.uc
@@ -117,8 +117,9 @@ function client_add(interface, mac, state) {
 
 	let accounting = (config[interface].acct_server && config[interface].acct_secret);
 
-	defval = config[interface].acct_interval || 600;
-	let interval = (state.data?.radius?.reply['Acct-Interim-Interval'] || defval) * 1000;
+	// RFC: NAS local interval value *must* override RADIUS attribute
+	defval = config[interface].acct_interval;
+	let interval = (defval || state.data?.radius?.reply['Acct-Interim-Interval'] || 0) * 1000;
 
 	defval = config[interface].session_timeout || 0;
 	let session = (state.data?.radius?.reply['Session-Timeout'] || defval);
@@ -141,7 +142,7 @@ function client_add(interface, mac, state) {
 		clients[interface][mac].ip6addr = state.ip6addr;
 	if (state.data?.radius?.request) {
 		clients[interface][mac].radius = state.data.radius.request;
-		if (accounting)
+		if (accounting && interval)
 			clients[interface][mac].timeout = uloop.timer(interval, () => radius_interim(interface, mac));
 	}
 	syslog(interface, mac, 'adding client');