diff --git a/README.md b/README.md
index c0e8748..84a1b69 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,9 @@
 Validation of IBAN and BBAN numbers and other country specific bank account formats. Extendable with custom validations
 
 # Rules
-## Swedish Bban rules is implemented based on this document:
-https://www.bankgirot.se/globalassets/dokument/anvandarmanualer/bankernaskontonummeruppbyggnad_anvandarmanual_sv.pdf
-EG25001000540
-EG250010005400000100026173878
\ No newline at end of file
+## Swedish Bban rules 
+Implementation is based on this document:
+* https://www.bankgirot.se/globalassets/dokument/anvandarmanualer/bankernaskontonummeruppbyggnad_anvandarmanual_sv.pdf
+
+And ading supporting for 5 digit clearing number as well:
+* https://www.swedbank.se/privat/betala-och-overfora/konton/clearingnummer/5-siffriga-clearingnummer-som-borjar-pa-siffran-8.html
diff --git a/src/validators/SwedishBbanValidation.ts b/src/validators/SwedishBbanValidation.ts
index 2c697ef..cde7653 100644
--- a/src/validators/SwedishBbanValidation.ts
+++ b/src/validators/SwedishBbanValidation.ts
@@ -15,11 +15,11 @@ interface Account{
 }
 
 function extractClearingNumber(_clearing: string | null, bban: string) {
-    return _clearing ? parseInt(_clearing) : parseInt(bban.substr(0, 4))
+    return _clearing ? parseInt(_clearing) : parseInt(bban.slice(0, 4))
 }
 
 function extractAccountNumberOnly(_clearing: string | null, bban: string) {
-    return _clearing ? bban : bban.substr(4)
+    return _clearing ? bban : bban.slice(4)
 }
 
 function getType(clearingNumber:number):string {
@@ -64,11 +64,14 @@ function parseClearingAndAccountNumber(_clearing:string|null, bban:string):Accou
 export class SwedishBbanValidation implements IStrictValidation {
     _config: types.BankAccountValidationConfig
     private _syntaxTester: RegExp
+    private _syntaxTesterSwedbank: RegExp
 
     constructor(config: Partial<types.BankAccountValidationConfig>) {
         this._config = defaultsDeep({}, config, defaultConfig)
         /* syntax: optional clearing (4 digit) + account number (7, 9 or 10 digit)*/
         this._syntaxTester = /^(\d{4}(:?\d{7}|\d{9}|\d{10})|(:?\d{7}|\d{9}|\d{10}))$/
+        /* syntax: 5 digit clearing starting with 8 + nolla + account number 9 digit */
+        this._syntaxTesterSwedbank = /^8\d{4}0\d{9}$/
     }
 
     canValidate(input: ValidationInput): Boolean {
@@ -94,7 +97,7 @@ export class SwedishBbanValidation implements IStrictValidation {
 
         const account = parseClearingAndAccountNumber(input.clearingNumber || null, input.accountNumber)
 
-        const validSyntax = this._syntaxTester.test(account.bban)
+        const validSyntax = this._syntaxTester.test(account.bban) || this._syntaxTesterSwedbank.test(account.bban)
 
         if (!validSyntax){
             return {
@@ -104,11 +107,13 @@ export class SwedishBbanValidation implements IStrictValidation {
         }
 
         if (
-            account.type === '1.1' && account.length === 7  && sweMod11(account.bban.substr(1)) ||
+            account.type === '1.1' && account.length === 7  && sweMod11(account.bban.slice(1)) ||
             account.type === '1.2' && account.length === 7  && sweMod11(account.bban) ||
             account.type === '2.1' && account.length === 10 && sweMod10(account.accountNumber) ||
             account.type === '2.2' && account.length === 9  && sweMod11(account.accountNumber) ||
-            account.type === '2.3' && account.length === 10 && sweMod10(account.accountNumber)
+            account.type === '2.3' && account.length === 10 && sweMod10(account.accountNumber) ||
+            // supporting 5 digit clearing number - Swedbank
+            account.type === '2.3' && account.length === 11 && sweMod10(account.accountNumber.slice(-10))
         ){
             return {
                 valid: true,
diff --git a/test/SE/testBbanValidation.ts b/test/SE/testBbanValidation.ts
index 6fe4b50..2bb6212 100644
--- a/test/SE/testBbanValidation.ts
+++ b/test/SE/testBbanValidation.ts
@@ -59,12 +59,6 @@ describe('SwedishBbanValidation', ()=> {
                 reason: null
             })
         })
-        it('should validate a valid type 2.3 Swedish BBAN account (Swedbank)', ()=>{
-            chai.expect(validation.validate({accountNumber: '83881122211004'})).to.deep.equal({
-                'valid': true,
-                reason: null
-            })
-        })
 
         it('should invalidate an invalid Swedish BBAN account', ()=>{
             chai.expect(validation.validate({accountNumber: '54401122004'})).to.deep.equal({
@@ -135,12 +129,6 @@ describe('SwedishBbanValidation', ()=> {
                 reason: null
             })
         })
-        it('should validate a valid type 2.3 Swedish BBAN account (Swedbank)', ()=>{
-            chai.expect(validation.validate({clearingNumber:'8388', accountNumber: '1122211004'})).to.deep.equal({
-                'valid': true,
-                reason: null
-            })
-        })
 
         xit('should invalidate an invalid Swedish BBAN account', ()=>{
             chai.expect(validation.validate({clearingNumber:'5440', accountNumber: '1122004'})).to.deep.equal({
@@ -171,6 +159,54 @@ describe('SwedishBbanValidation', ()=> {
         })
     })
 
+    describe('4 char clearing number type 2.3 (that starts with 8) Swedish Swedbank BBAN account ', ()=> {
+        // CCCC0KKKKKKKKK
+        // (4 siffror i clearingnumret, en extra nolla, 9 siffror i kontonumret - totalt 14 siffror).
+        it('should validate a valid type 2.3 Swedish BBAN account (Swedbank)', ()=>{ // TODO: here
+            chai.expect(validation.validate({accountNumber: '83880122211006'})).to.deep.equal({
+                'valid': true,
+                reason: null
+            })
+        })
+        it('should validate account number with starting 0', ()=>{
+            chai.expect(validation.validate({clearingNumber:'8388', accountNumber: '0122211006'})).to.deep.equal({
+                'valid': true,
+                reason: null
+            })
+        })
+
+        it('should validate account number without starting 0', ()=>{
+            chai.expect(validation.validate({clearingNumber:'8388', accountNumber: '122211006'})).to.deep.equal({
+                'valid': true,
+                reason: null
+            })
+        })
+    })
+
+    describe('5 char clearing number type 2.3 (that starts with 8) Swedish Swedbank BBAN account ', ()=> {
+        // CCCCC0KKKKKKKKK
+        // (5 siffror i clearingnumret, en extra nolla, 9 siffror i kontonumret - totalt 15 siffror).
+        it('should validate a valid type 2.3 Swedish BBAN account (Swedbank)', ()=>{
+            chai.expect(validation.validate({accountNumber: '838890122211006'})).to.deep.equal({
+                'valid': true,
+                reason: null
+            })
+        })
+        it('should validate account number with starting 0', ()=>{
+            chai.expect(validation.validate({clearingNumber:'83889', accountNumber: '0122211006'})).to.deep.equal({
+                'valid': true,
+                reason: null
+            })
+        })
+
+        it('should validate account number without starting 0', ()=>{
+            chai.expect(validation.validate({clearingNumber:'83889', accountNumber: '122211006'})).to.deep.equal({
+                'valid': true,
+                reason: null
+            })
+        })
+    })
+
     describe('when determining suitability', ()=> {
         it('should accept a Swedish country', ()=>{
             chai.expect(validation.canValidate({accountNumber: 'invalid', countryCode: 'SE', type: 'bban'})).to.equal(true)