diff --git a/postcodes/management/commands/loadpostcodeconcordance.py b/postcodes/management/commands/loadpostcodeconcordance.py
index 4d64ab0..bb7d7d7 100644
--- a/postcodes/management/commands/loadpostcodeconcordance.py
+++ b/postcodes/management/commands/loadpostcodeconcordance.py
@@ -58,7 +58,7 @@ def handle(self, *args, **options):
             try:
                 (postcode, created) = Postcode.objects.get_or_create(code=code)
             except ValidationError as e:
-                log.error("{}: {!r}".format(code, e))
+                log.error("%s: %s", code, repr(e))
                 continue
 
             try:
@@ -70,12 +70,12 @@ def handle(self, *args, **options):
                         boundary = boundaries.get(**{options['search-field']: term})
                     boundaries_seen[term] = boundary
             except Boundary.DoesNotExist:
-                log.error("No boundary {} matches {}".format(options['search-field'], term))
+                log.error("No boundary %s matches %s", options['search-field'], term)
                 continue
 
-            path = '{}/{}'.format(boundary_set.slug, boundary.slug)
+            path = f'{boundary_set.slug}/{boundary.slug}'
             if PostcodeConcordance.objects.filter(code=postcode, boundary=path).exists():
-                log.warning("Concordance already exists between {} and {}".format(code, path))
+                log.warning("Concordance already exists between %s and %s", code, path)
                 continue
 
             PostcodeConcordance.objects.create(
diff --git a/postcodes/management/commands/loadpostcodes.py b/postcodes/management/commands/loadpostcodes.py
index bbe3022..c395b63 100644
--- a/postcodes/management/commands/loadpostcodes.py
+++ b/postcodes/management/commands/loadpostcodes.py
@@ -36,4 +36,4 @@ def handle(self, *args, **options):
                     province=row['region'],
                 ).save()
             except ValidationError as e:
-                log.error("{}: {!r}".format(row['code'], e))
+                log.error("%s: %s", row['code'], repr(e))
diff --git a/postcodes/models.py b/postcodes/models.py
index 92b04e3..0446233 100644
--- a/postcodes/models.py
+++ b/postcodes/models.py
@@ -158,4 +158,4 @@ class Meta:
         unique_together = (('code', 'boundary'))
 
     def __str__(self):
-        return '{} -> {}'.format(self.code_id, self.boundary)
+        return f'{self.code_id} -> {self.boundary}'