diff --git a/src/types.py b/src/types.py
new file mode 100644
index 0000000..8c383c8
--- /dev/null
+++ b/src/types.py
@@ -0,0 +1,46 @@
+from pydantic import BaseModel
+from typing import Any, Dict, Literal
+
+Server_call_return = Dict[str, Any]
+class Invoice(BaseModel):
+    name: str
+    format: Literal["XML", "JSON", "HTML", "PDF"]
+    source: Literal["url", "file_upload", "raw_data", "text"]
+    data: str
+
+class Location(BaseModel):
+    type: Literal["xpath", "line"]
+    xpath: str
+    line: int
+    column: int
+
+class Violation(BaseModel):
+    rule_id: str
+    is_fatal: bool
+    location: Location
+    test: str
+    message: str
+    suggestion: str
+
+class Evaluation(BaseModel):
+    aspect: Literal["wellformedness", "syntax", "peppol", "schema"]
+    is_valid: bool
+    num_rules_fired: int
+    num_rules_failed: int
+    num_violations: int
+    violations: list[Violation]
+
+
+class Report(BaseModel):
+    report_id: int
+    score: int
+    date_generated: str
+    invoice_name: str
+    invoice_raw: str
+    invoice_hash: str
+    is_valid: bool
+    total_num_violations: int
+    wellformedness: Evaluation
+    schemaEvaluation: Evaluation
+    syntax: Evaluation
+    peppol: Evaluatio
\ No newline at end of file
diff --git a/tests/helpers.py b/tests/helpers.py
index caaba75..06fc8d2 100644
--- a/tests/helpers.py
+++ b/tests/helpers.py
@@ -92,3 +92,10 @@ def invalidate_invoice(invoice_text, choice, tag_name, text, index):
             pass
 
     return etree.tostring(root).decode('utf-8')
+
+
+def replace_part_of_string(string, start, end, replace):
+    return string[:start] + replace + string[end:]
+
+def squeeze_text_inbetween(string, cursor, txt):
+    return string[:cursor] + txt + string[cursor:]
\ No newline at end of file
diff --git a/tests/schema_test.py b/tests/schema_test.py
new file mode 100644
index 0000000..423de0f
--- /dev/null
+++ b/tests/schema_test.py
@@ -0,0 +1,117 @@
+from src.types import Invoice, Evaluation
+from tests.server_calls import report_schemavalid_v1
+from tests.constants import VALID_INVOICE_TEXT
+from tests.helpers import *
+
+"""
+=====================================
+/report/schemavalid/v1 TESTS
+=====================================
+"""
+def test_UBL_VersionID_specified_twice_invalid():
+    # Invalidating the date
+    data = squeeze_text_inbetween(VALID_INVOICE_TEXT, 530, 532, "20")
+
+    invoice = Invoice(name="My Invoice", format="XML", source="text", data=data)
+
+    schema_evaluation = report_schemavalid_v1(invoice)
+    schema_evaluation = Evaluation(**schema_evaluation)
+
+    assert schema_evaluation.aspect == "schema"
+
+    # We expect exactly 1 rule to fail due to the capitalised tag
+    assert schema_evaluation.num_rules_failed == 1
+
+    # We expect exactly 1 violation due to the capitalised tag
+    assert schema_evaluation.num_violations == 1
+
+    # Thus there should be exactly 1 violation in the violation list
+    assert len(schema_evaluation.violations) == 1
+
+    violation = schema_evaluation.violations[0]
+
+    # Check that the violation is flagged as fatal
+    assert violation.is_fatal
+
+    # Check that the violation has a non-empty message, test and suggestion
+    assert violation.message
+    assert violation.test
+    assert violation.suggestion
+    
+    assert violation.location.type == "line"
+
+    # Check that the location line/column are were the violation is
+    assert violation.location.line == 1
+    assert violation.location.column == 555
+
+def test_schema_currency_id_invalid():
+    # Invalidating the date
+    data = insert_into_string(VALID_INVOICE_TEXT, 6200, "D")
+
+    invoice = Invoice(name="My Invoice", format="XML", source="text", data=data)
+
+    schema_evaluation = report_schemavalid_v1(invoice)
+    schema_evaluation = Evaluation(**schema_evaluation)
+
+    assert schema_evaluation.aspect == "schema"
+
+    # We expect exactly 1 rule to fail due to the capitalised tag
+    assert schema_evaluation.num_rules_failed == 1
+
+    # We expect exactly 1 violation due to the capitalised tag
+    assert schema_evaluation.num_violations == 1
+
+    # Thus there should be exactly 1 violation in the violation list
+    assert len(schema_evaluation.violations) == 1
+
+    violation = schema_evaluation.violations[0]
+
+    # Check that the violation is flagged as fatal
+    assert violation.is_fatal
+
+    # Check that the violation has a non-empty message, test and suggestion
+    assert violation.message
+    assert violation.test
+    assert violation.suggestion
+    
+    assert violation.location.type == "line"
+
+    # Check that the location line/column are were the violation is
+    assert violation.location.line == 1
+    assert violation.location.column == 555
+
+def test_schema_percent_invalid():
+    # Invalidating the date
+    data = insert_into_string(VALID_INVOICE_TEXT, 6316, "0")
+
+    invoice = Invoice(name="My Invoice", format="XML", source="text", data=data)
+
+    schema_evaluation = report_schemavalid_v1(invoice)
+    schema_evaluation = Evaluation(**schema_evaluation)
+
+    assert schema_evaluation.aspect == "schema"
+
+    # We expect exactly 1 rule to fail due to the capitalised tag
+    assert schema_evaluation.num_rules_failed == 1
+
+    # We expect exactly 1 violation due to the capitalised tag
+    assert schema_evaluation.num_violations == 1
+
+    # Thus there should be exactly 1 violation in the violation list
+    assert len(schema_evaluation.violations) == 1
+
+    violation = schema_evaluation.violations[0]
+
+    # Check that the violation is flagged as fatal
+    assert violation.is_fatal
+
+    # Check that the violation has a non-empty message, test and suggestion
+    assert violation.message
+    assert violation.test
+    assert violation.suggestion
+    
+    assert violation.location.type == "line"
+
+    # Check that the location line/column are were the violation is
+    assert violation.location.line == 1
+    assert violation.location.column == 555
\ No newline at end of file