diff --git a/entrypoint.sh b/entrypoint.sh
index 81f8065..3dfc947 100755
--- a/entrypoint.sh
+++ b/entrypoint.sh
@@ -36,8 +36,8 @@ current_branch=$(git rev-parse --abbrev-ref HEAD)
 pre_release="true"
 IFS=',' read -ra branch <<< "$release_branches"
 for b in "${branch[@]}"; do
-    echo "Is $b a match for ${current_branch}"
-    if [[ "${current_branch}" =~ $b ]]
+    # check if ${current_branch} is in ${release_branches}
+    if [[ "$current_branch" == "$b" ]]
     then
         pre_release="false"
     fi
@@ -46,50 +46,55 @@ echo "pre_release = $pre_release"
 
 # fetch tags
 git fetch --tags
-    
-tagFmt="^v?[0-9]+\.[0-9]+\.[0-9]+$" 
-preTagFmt="^v?[0-9]+\.[0-9]+\.[0-9]+(-$suffix\.[0-9]+)?$" 
+
+tagFmt="^v?[0-9]+\.[0-9]+\.[0-9]+$"
+preTagFmt="^v?[0-9]+\.[0-9]+\.[0-9]+(-$suffix\.[0-9]+)$"
 
 # get latest tag that looks like a semver (with or without v)
 case "$tag_context" in
     *repo*) 
-        taglist="$(git for-each-ref --sort=-v:refname --format '%(refname:lstrip=2)' | grep -E "$tagFmt")"
-        tag="$(semver $taglist | tail -n 1)"
-
-        pre_taglist="$(git for-each-ref --sort=-v:refname --format '%(refname:lstrip=2)' | grep -E "$preTagFmt")"
-        pre_tag="$(semver "$pre_taglist" | tail -n 1)"
+        tag="$(git for-each-ref --sort=-v:refname --format '%(refname:lstrip=2)' | grep -E "$tagFmt" | head -n 1)"
+        pre_tag="$(git for-each-ref --sort=-v:refname --format '%(refname:lstrip=2)' | grep -E "$preTagFmt" | head -n 1)"
         ;;
     *branch*) 
-        taglist="$(git tag --list --merged HEAD --sort=-v:refname | grep -E "$tagFmt")"
-        tag="$(semver $taglist | tail -n 1)"
-
-        pre_taglist="$(git tag --list --merged HEAD --sort=-v:refname | grep -E "$preTagFmt")"
-        pre_tag=$(semver "$pre_taglist" | tail -n 1)
+        tag="$(git tag --list --merged HEAD --sort=-v:refname | grep -E "$tagFmt" | head -n 1)"
+        pre_tag="$(git tag --list --merged HEAD --sort=-v:refname | grep -E "$preTagFmt" | head -n 1)"
         ;;
-    * ) echo "Unrecognised context"; exit 1;;
+    * ) echo "Unrecognised context"
+        exit 1;;
 esac
 
-
 # if there are none, start tags at INITIAL_VERSION which defaults to 0.0.0
 if [ -z "$tag" ]
 then
-    log=$(git log --pretty='%B')
-    tag="$initial_version"
+    log=$(git log --pretty='%B' --)
+    if $with_v
+    then
+        tag="v$initial_version"
+    else
+        tag="$initial_version"
+    fi
     if [ -z "$pre_tag" ] && $pre_release
     then
-      pre_tag="$initial_version"
+        if $with_v
+        then
+            pre_tag="v$initial_version"
+        else
+            pre_tag="$initial_version"
+        fi
     fi
 else
-    log=$(git log $tag..HEAD --pretty='%B')
+    log=$(git log ${tag}..HEAD --pretty='%B' --)
 fi
 
 # get current commit hash for tag
-tag_commit=$(git rev-list -n 1 $tag)
+tag_commit=$(git rev-list -n 1 ${tag})
 
 # get current commit hash
 commit=$(git rev-parse HEAD)
 
-if [ "$tag_commit" == "$commit" ]; then
+if [ "$tag_commit" == "$commit" ]
+then
     echo "No new commits since previous tag. Skipping..."
     echo ::set-output name=tag::$tag
     exit 0
@@ -102,16 +107,24 @@ then
 fi
 
 case "$log" in
-    *#major* ) new=$(semver -i major $tag); part="major";;
-    *#minor* ) new=$(semver -i minor $tag); part="minor";;
-    *#patch* ) new=$(semver -i patch $tag); part="patch";;
+    *#major* ) new=$(semver -i major ${tag}); part="major";;
+    *#minor* ) new=$(semver -i minor ${tag}); part="minor";;
+    *#patch* ) new=$(semver -i patch ${tag}); part="patch";;
     *#none* ) 
-        echo "Default bump was set to none. Skipping..."; echo ::set-output name=new_tag::$tag; echo ::set-output name=tag::$tag; exit 0;;
+        echo "Default bump was set to none. Skipping..."
+        echo ::set-output name=new_tag::$tag
+        echo ::set-output name=tag::$tag
+        exit 0;;
     * ) 
-        if [ "$default_semvar_bump" == "none" ]; then
-            echo "Default bump was set to none. Skipping..."; echo ::set-output name=new_tag::$tag; echo ::set-output name=tag::$tag; exit 0 
+        if [ "$default_semvar_bump" == "none" ]
+        then
+            echo "Default bump was set to none. Skipping..."
+            echo ::set-output name=new_tag::$tag
+            echo ::set-output name=tag::$tag
+            exit 0 
         else 
-            new=$(semver -i "${default_semvar_bump}" $tag); part=$default_semvar_bump 
+            new=$(semver -i "${default_semvar_bump}" ${tag})
+            part=$default_semvar_bump 
         fi 
         ;;
 esac
@@ -119,33 +132,39 @@ esac
 if $pre_release
 then
     # Already a prerelease available, bump it
-    if [[ "$pre_tag" == *"$new"* ]]; then
-        new=$(semver -i prerelease $pre_tag --preid $suffix); part="pre-$part"
+    if [[ "$pre_tag" =~ "$new" ]] && [[ "$pre_tag" =~ "$suffix" ]]
+    then
+        if $with_v
+        then
+            new="v$(semver -i prerelease ${pre_tag} --preid ${suffix})"
+        else
+            new="$(semver -i prerelease ${pre_tag} --preid ${suffix})"
+        fi
+        echo -e "Bumping ${suffix} pre-tag ${pre_tag}. New pre-tag ${new}"
     else
-        new="$new-$suffix.1"; part="pre-$part"
+        if $with_v
+        then
+            new="v$new-$suffix.0"
+        else
+            new="$new-$suffix.0"
+        fi
+        echo -e "Setting ${suffix} pre-tag ${pre_tag}. With pre-tag ${new}"
+    fi
+    part="pre-$part"
+else
+    echo -e "Bumping tag ${tag}. New tag ${new}"
+    if $with_v
+    then
+        new="v$new"
     fi
 fi
 
-echo $part
-
-# prefix with 'v'
-if $with_v
-then
-	new="v$new"
-fi
-
-if [ ! -z $custom_tag ]
+# as defined in readme if CUSTOM_TAG is used any semver calculations are irrelevant.
+if ! [ -z "$custom_tag" ]
 then
     new="$custom_tag"
 fi
 
-if $pre_release
-then
-    echo -e "Bumping tag ${pre_tag}. \n\tNew tag ${new}"
-else
-    echo -e "Bumping tag ${tag}. \n\tNew tag ${new}"
-fi
-
 # set outputs
 echo ::set-output name=new_tag::$new
 echo ::set-output name=part::$part
@@ -160,7 +179,7 @@ fi
 echo ::set-output name=tag::$new
 
 # create local git tag
-git tag $new
+git tag "$new"
 
 # push new tag ref to github
 dt=$(date '+%Y-%m-%dT%H:%M:%SZ')
@@ -184,7 +203,8 @@ EOF
 git_ref_posted=$( echo "${git_refs_response}" | jq .ref | tr -d '"' )
 
 echo "::debug::${git_refs_response}"
-if [ "${git_ref_posted}" = "refs/tags/${new}" ]; then
+if [ "${git_ref_posted}" = "refs/tags/${new}" ]
+then
   exit 0
 else
   echo "::error::Tag was not created properly."