diff --git a/pySim-prog.py b/pySim-prog.py
index bfb40b2..09a5d70 100755
--- a/pySim-prog.py
+++ b/pySim-prog.py
@@ -274,6 +274,10 @@
 	# Digitize MCC/MNC (5 or 6 digits)
 	plmn_digits = _mcc_mnc_digits(mcc, mnc)
 
+	if opts.name is not None:
+		if len(opts.name) > 16:
+			raise ValueError('Service Provider Name must max 16 characters!');
+
 	# ICCID (19 digits, E.118), though some phase1 vendors use 20 :(
 	if opts.iccid is not None:
 		iccid = opts.iccid
diff --git a/pySim/cards.py b/pySim/cards.py
index faaeca3..022182c 100644
--- a/pySim/cards.py
+++ b/pySim/cards.py
@@ -613,8 +613,9 @@
 			data, sw = self._scc.update_binary('00F7', content)
 
 		# set Service Provider Name
-		content = enc_spn(p['name'], True, True)
-		data, sw = self._scc.update_binary('6F46', rpad(content, 32))
+		if p.get('name') is not None:
+			content = enc_spn(p['name'], True, True)
+			data, sw = self._scc.update_binary('6F46', rpad(content, 32))
 
 		# write EF.IMSI
 		data, sw = self._scc.update_binary('6f07', enc_imsi(p['imsi']))