diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 9fd45e0..8671c63 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -14,9 +14,13 @@ jobs:
 
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        feature: [eu_vat, gb_vat, ch_vat, no_vat]
+
     steps:
-    - uses: actions/checkout@v4
-    - name: Build
-      run: cargo build --verbose
-    - name: Run tests
-      run: cargo test --verbose
+      - uses: actions/checkout@v4
+      - name: Build
+        run: cargo build --verbose --no-default-features --features ${{ matrix.feature }}
+      - name: Run tests
+        run: cargo test --verbose --no-default-features --features ${{ matrix.feature }}
diff --git a/src/ch_vat/bfs.rs b/src/ch_vat/bfs.rs
index fa7634b..213562f 100644
--- a/src/ch_vat/bfs.rs
+++ b/src/ch_vat/bfs.rs
@@ -4,8 +4,8 @@ use reqwest::header::{HeaderMap, HeaderName, HeaderValue, ACCEPT, CONTENT_TYPE};
 use roxmltree;
 use serde_json::json;
 use crate::verification::{Verifier, Verification, VerificationStatus, VerificationResponse};
-use crate::tax_id::TaxId;
 use crate::errors::VerificationError;
+use crate::TaxId;
 
 // INFO(2024-05-07 mollemoll):
 // https://www.bfs.admin.ch/bfs/en/home/registers/enterprise-register/enterprise-identification/uid-register/uid-interfaces.html#-125185306
diff --git a/src/ch_vat/mod.rs b/src/ch_vat/mod.rs
index 63f1fbc..4cb5937 100644
--- a/src/ch_vat/mod.rs
+++ b/src/ch_vat/mod.rs
@@ -3,7 +3,7 @@ mod bfs;
 use std::collections::HashMap;
 use lazy_static::lazy_static;
 use regex::Regex;
-use crate::tax_id::TaxIdType;
+use crate::TaxIdType;
 use crate::verification::Verifier;
 
 lazy_static! {
diff --git a/src/gb_vat/hmrc.rs b/src/gb_vat/hmrc.rs
index bff6beb..386beb8 100644
--- a/src/gb_vat/hmrc.rs
+++ b/src/gb_vat/hmrc.rs
@@ -1,6 +1,6 @@
 use serde_json::json;
 use crate::errors::VerificationError;
-use crate::tax_id::TaxId;
+use crate::TaxId;
 use crate::verification::{Verification, VerificationResponse, VerificationStatus, Verifier};
 
 // INFO(2024-05-08 mollemoll):
diff --git a/src/gb_vat/mod.rs b/src/gb_vat/mod.rs
index 122857e..960e2be 100644
--- a/src/gb_vat/mod.rs
+++ b/src/gb_vat/mod.rs
@@ -3,7 +3,7 @@ mod hmrc;
 use std::collections::HashMap;
 use lazy_static::lazy_static;
 use regex::Regex;
-use crate::tax_id::TaxIdType;
+use crate::TaxIdType;
 use crate::verification::Verifier;
 
 lazy_static! {
@@ -43,7 +43,7 @@ impl TaxIdType for GbVat {
 #[cfg(test)]
 mod tests {
     use crate::gb_vat::GbVat;
-    use crate::tax_id::TaxIdType;
+    use crate::TaxIdType;
 
     #[test]
     fn test_gb_vat() {
@@ -62,11 +62,11 @@ mod tests {
         ];
 
         for valid in valid_vat_numbers {
-            assert!(GbVat::validate_syntax(&GBVat, valid).is_ok());
+            assert!(GbVat::validate_syntax(&GbVat, valid).is_ok());
         }
 
         for invalid in invalid_vat_numbers {
-            assert!(GbVat::validate_syntax(&GBVat, invalid).is_err());
+            assert!(GbVat::validate_syntax(&GbVat, invalid).is_err());
         }
 
     }
diff --git a/src/lib.rs b/src/lib.rs
index 377f310..886f507 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -125,14 +125,12 @@ mod tests {
 
     #[test]
     fn test_validate_syntax() {
-        let mut valid_vat_numbers: Vec<&str>;
+        let mut valid_vat_numbers: Vec<&str> = Vec::new();
         #[cfg(feature = "eu_vat")]
         {
-            valid_vat_numbers = vec![
-                "SE123456789101",
-                "EL123456789",
-                "XI591819014",
-            ];
+            valid_vat_numbers.push("SE123456789101");
+            valid_vat_numbers.push("EL123456789");
+            valid_vat_numbers.push("XI591819014");
         }
         #[cfg(feature = "gb_vat")]
         valid_vat_numbers.push("GB591819014");
@@ -160,26 +158,77 @@ mod tests {
     }
 
     #[test]
-    fn test_validate_syntax_failed_validation() {
+    fn test_new_unsupported_country() {
+        let tax_id = TaxId::new("XX123456789");
+        assert!(tax_id.is_err());
+        assert_eq!(tax_id.unwrap_err(), ValidationError::UnsupportedCountryCode("XX".to_string()));
+    }
+
+
+    #[cfg(feature = "eu_vat")]
+    #[test]
+    fn test_validate_eu_syntax_fail() {
         let validation = TaxId::validate_syntax("SE12");
         assert!(validation.is_err());
         assert_eq!(validation.unwrap_err(), ValidationError::InvalidSyntax);
     }
 
+    #[cfg(feature = "gb_vat")]
     #[test]
-    fn test_new_failed_validation() {
-        let tax_id = TaxId::new("XX123456789");
-        assert!(tax_id.is_err());
-        assert_eq!(tax_id.unwrap_err(), ValidationError::UnsupportedCountryCode("XX".to_string()));
+    fn test_validate_gb_syntax_fail() {
+        let validation = TaxId::validate_syntax("GB12");
+        assert!(validation.is_err());
+        assert_eq!(validation.unwrap_err(), ValidationError::InvalidSyntax);
     }
 
+    #[cfg(feature = "ch_vat")]
     #[test]
-    fn test_new_unsupported_country_code_err() {
+    fn test_validate_ch_syntax_fail() {
+        let validation = TaxId::validate_syntax("CHE12");
+        assert!(validation.is_err());
+        assert_eq!(validation.unwrap_err(), ValidationError::InvalidSyntax);
+    }
+
+    #[cfg(feature = "no_vat")]
+    #[test]
+    fn test_validate_no_syntax_fail() {
+        let validation = TaxId::validate_syntax("NO12");
+        assert!(validation.is_err());
+        assert_eq!(validation.unwrap_err(), ValidationError::InvalidSyntax);
+    }
+
+    #[cfg(feature = "eu_vat")]
+    #[test]
+    fn test_eu_new_unsupported_country_code_err() {
         let tax_id = TaxId::new("SE12");
         assert!(tax_id.is_err());
         assert_eq!(tax_id.unwrap_err(), ValidationError::InvalidSyntax);
     }
 
+    #[cfg(feature = "gb_vat")]
+    #[test]
+    fn test_new_gb_unsupported_country_code_err() {
+        let tax_id = TaxId::new("GB12");
+        assert!(tax_id.is_err());
+        assert_eq!(tax_id.unwrap_err(), ValidationError::InvalidSyntax);
+    }
+
+    #[cfg(feature = "ch_vat")]
+    #[test]
+    fn test_new_ch_unsupported_country_code_err() {
+        let tax_id = TaxId::new("CHE12");
+        assert!(tax_id.is_err());
+        assert_eq!(tax_id.unwrap_err(), ValidationError::InvalidSyntax);
+    }
+
+    #[cfg(feature = "no_vat")]
+    #[test]
+    fn test_new_no_unsupported_country_code_err() {
+        let tax_id = TaxId::new("NO12");
+        assert!(tax_id.is_err());
+        assert_eq!(tax_id.unwrap_err(), ValidationError::InvalidSyntax);
+    }
+
     #[cfg(feature = "eu_vat")]
     #[test]
     fn test_new_eu_vat() {
diff --git a/src/no_vat/brreg.rs b/src/no_vat/brreg.rs
index d82d24a..b55ec94 100644
--- a/src/no_vat/brreg.rs
+++ b/src/no_vat/brreg.rs
@@ -3,10 +3,10 @@ use lazy_static::lazy_static;
 use reqwest::header::{HeaderMap, HeaderValue, ACCEPT};
 use serde_json::{json, Value};
 use crate::verification::{Verifier, Verification, VerificationStatus, VerificationResponse};
-use crate::tax_id::TaxId;
 use crate::errors::VerificationError;
 use crate::no_vat::NoVat;
 use crate::no_vat::translator::translate_keys;
+use crate::TaxId;
 
 // INFO(2024-05-08 mollemoll):
 // Data from Brønnøysund Register Centre
@@ -60,7 +60,7 @@ impl Verifier for BRReg {
     fn make_request(&self, tax_id: &TaxId) -> Result<VerificationResponse, VerificationError> {
         let client = reqwest::blocking::Client::new();
         let res = client
-            .get(format!("{}/{}", BASE_URI, NoVat::extract_org_number(&NOVat, tax_id)))
+            .get(format!("{}/{}", BASE_URI, NoVat::extract_org_number(&NoVat, tax_id)))
             .headers(HEADERS.clone())
             .send()
             .map_err(VerificationError::HttpError)?;
diff --git a/src/no_vat/mod.rs b/src/no_vat/mod.rs
index 2d3c774..b713ec7 100644
--- a/src/no_vat/mod.rs
+++ b/src/no_vat/mod.rs
@@ -4,7 +4,7 @@ mod translator;
 use std::collections::HashMap;
 use lazy_static::lazy_static;
 use regex::Regex;
-use crate::tax_id::{TaxId, TaxIdType};
+use crate::{TaxId, TaxIdType};
 use crate::verification::Verifier;
 
 lazy_static! {
diff --git a/src/verification.rs b/src/verification.rs
index 9655201..b447940 100644
--- a/src/verification.rs
+++ b/src/verification.rs
@@ -99,7 +99,16 @@ mod tests {
 
     #[test]
     fn test_verify() {
-        let tax_id = TaxId::new("SE123456789101").unwrap();
+        #[cfg(feature="eu_vat")]
+        let value = "SE123456789101";
+        #[cfg(feature="gb_vat")]
+        let value = "GB123456789";
+        #[cfg(feature="ch_vat")]
+        let value = "CHE123456789";
+        #[cfg(feature = "no_vat")]
+        let value = "NO123456789";
+        
+        let tax_id = TaxId::new(value).unwrap();
         let verifier = TestVerifier;
         let verification = verifier.verify(&tax_id).unwrap();
         assert_eq!(verification.status(), &VerificationStatus::Verified);