diff --git a/models/baseModels/Invoice/Invoice.ts b/models/baseModels/Invoice/Invoice.ts
index 8ea493cd..0b4bb73e 100644
--- a/models/baseModels/Invoice/Invoice.ts
+++ b/models/baseModels/Invoice/Invoice.ts
@@ -18,7 +18,6 @@ import {
 } from 'models/helpers';
 import { InventorySettings } from 'models/inventory/InventorySettings';
 import { StockTransfer } from 'models/inventory/StockTransfer';
-import { getStockTransfer } from 'models/inventory/tests/helpers';
 import { Transactional } from 'models/Transactional/Transactional';
 import { ModelNameEnum } from 'models/types';
 import { Money } from 'pesa';
@@ -74,6 +73,12 @@ export abstract class Invoice extends Transactional {
     return this.fyo.singles.SystemSettings?.currency ?? DEFAULT_CURRENCY;
   }
 
+  get stockTransferSchemaName() {
+    return this.isSales
+      ? ModelNameEnum.Shipment
+      : ModelNameEnum.PurchaseReceipt;
+  }
+
   constructor(schema: Schema, data: DocValueMap, fyo: Fyo) {
     super(schema, data, fyo);
     this._setGetCurrencies();
@@ -487,9 +492,7 @@ export abstract class Invoice extends Transactional {
       return null;
     }
 
-    const schemaName = this.isSales
-      ? ModelNameEnum.Shipment
-      : ModelNameEnum.PurchaseReceipt;
+    const schemaName = this.stockTransferSchemaName;
 
     const defaults = (this.fyo.singles.Defaults as Defaults) ?? {};
     let terms;
@@ -505,7 +508,6 @@ export abstract class Invoice extends Transactional {
       terms,
       backReference: this.name,
     };
-    console.log(data.backReference);
 
     const location =
       (this.fyo.singles.InventorySettings as InventorySettings)
@@ -521,7 +523,11 @@ export abstract class Invoice extends Transactional {
       const item = row.item;
       const quantity = row.stockNotTransferred;
       const trackItem = itemDoc.trackItem;
-      const rate = row.rate;
+      let rate = row.rate as Money;
+
+      if (this.exchangeRate && this.exchangeRate > 1) {
+        rate = rate.mul(this.exchangeRate);
+      }
 
       if (!quantity || !trackItem) {
         continue;
@@ -541,4 +547,54 @@ export abstract class Invoice extends Transactional {
 
     return transfer;
   }
+
+  async beforeCancel(): Promise<void> {
+    await super.beforeCancel();
+    await this._validateStockTransferCancelled();
+  }
+
+  async beforeDelete(): Promise<void> {
+    await super.beforeCancel();
+    await this._validateStockTransferCancelled();
+    await this._deleteCancelledStockTransfers();
+  }
+
+  async _deleteCancelledStockTransfers() {
+    const schemaName = this.stockTransferSchemaName;
+    const transfers = await this._getLinkedStockTransferNames(true);
+
+    for (const { name } of transfers) {
+      const st = await this.fyo.doc.getDoc(schemaName, name);
+      await st.delete();
+    }
+  }
+
+  async _validateStockTransferCancelled() {
+    const schemaName = this.stockTransferSchemaName;
+    const transfers = await this._getLinkedStockTransferNames(false);
+    if (!transfers?.length) {
+      return;
+    }
+
+    const names = transfers.map(({ name }) => name).join(', ');
+    const label = this.fyo.schemaMap[schemaName]?.label ?? schemaName;
+    throw new ValidationError(
+      this.fyo.t`Cannot cancel ${this.schema.label} ${this
+        .name!} because of the following ${label}: ${names}`
+    );
+  }
+
+  async _getLinkedStockTransferNames(cancelled: boolean) {
+    const name = this.name;
+    if (!name) {
+      throw new ValidationError(`Name not found for ${this.schema.label}`);
+    }
+
+    const schemaName = this.stockTransferSchemaName;
+    const transfers = (await this.fyo.db.getAllRaw(schemaName, {
+      fields: ['name'],
+      filters: { backReference: this.name!, cancelled },
+    })) as { name: string }[];
+    return transfers;
+  }
 }
diff --git a/models/inventory/StockTransfer.ts b/models/inventory/StockTransfer.ts
index 755874e5..00ac0df9 100644
--- a/models/inventory/StockTransfer.ts
+++ b/models/inventory/StockTransfer.ts
@@ -9,7 +9,6 @@ import { getLedgerLinkAction, getNumberSeries } from 'models/helpers';
 import { LedgerPosting } from 'models/Transactional/LedgerPosting';
 import { ModelNameEnum } from 'models/types';
 import { Money } from 'pesa';
-import { getMapFromList } from 'utils/index';
 import { StockTransferItem } from './StockTransferItem';
 import { Transfer } from './Transfer';
 
@@ -176,7 +175,10 @@ export abstract class StockTransfer extends Transfer {
       const notTransferred = (row.stockNotTransferred as number) ?? 0;
 
       const transferred = transferMap[item];
-      if (!transferred || !notTransferred) {
+      if (
+        typeof transferred !== 'number' ||
+        typeof notTransferred !== 'number'
+      ) {
         continue;
       }
 
@@ -218,4 +220,10 @@ export abstract class StockTransfer extends Transfer {
       return acc;
     }, {} as Record<string, number>);
   }
+
+  override duplicate(): Doc {
+    const doc = super.duplicate() as StockTransfer;
+    doc.backReference = undefined;
+    return doc;
+  }
 }
diff --git a/models/inventory/tests/testStockTransfer.spec.ts b/models/inventory/tests/testStockTransfer.spec.ts
index c62c6c91..51cc6023 100644
--- a/models/inventory/tests/testStockTransfer.spec.ts
+++ b/models/inventory/tests/testStockTransfer.spec.ts
@@ -1,12 +1,14 @@
 import {
   assertDoesNotThrow,
-  assertThrows
+  assertThrows,
 } from 'backend/database/tests/helpers';
+import { Invoice } from 'models/baseModels/Invoice/Invoice';
 import { ModelNameEnum } from 'models/types';
 import { RawValue } from 'schemas/types';
 import test from 'tape';
 import { closeTestFyo, getTestFyo, setupTestFyo } from 'tests/helpers';
 import { InventorySettings } from '../InventorySettings';
+import { StockTransfer } from '../StockTransfer';
 import { ValuationMethod } from '../types';
 import { getALEs, getItem, getSLEs, getStockTransfer } from './helpers';
 
@@ -285,4 +287,253 @@ test('Purchase Receipt, cancel and delete', async (t) => {
     'doc deleted'
   );
 });
+
+test('Purchase Invoice then Purchase Receipt', async (t) => {
+  const rate = testDocs.Item[item].rate as number;
+  const quantity = 3;
+  const pinv = fyo.doc.getNewDoc(ModelNameEnum.PurchaseInvoice) as Invoice;
+
+  const date = new Date('2022-01-04');
+  await pinv.set({
+    date,
+    party,
+    account: 'Creditors',
+  });
+  await pinv.append('items', { item, quantity, rate });
+  await pinv.sync();
+  await pinv.submit();
+
+  t.equal(pinv.name, 'PINV-1001', 'PINV name matches');
+  t.equal(pinv.stockNotTransferred, quantity, 'stock not transferred');
+  const prec = await pinv.getStockTransfer();
+  if (prec === null) {
+    return t.ok(false, 'prec was null');
+  }
+
+  prec.date = new Date('2022-01-05');
+  t.equal(
+    ModelNameEnum.PurchaseReceipt,
+    prec.schemaName,
+    'stock transfer is a PREC'
+  );
+  t.equal(prec.backReference, pinv.name, 'back reference is set');
+  t.equal(prec.items?.[0].quantity, quantity, 'PREC transfers quantity');
+
+  await assertDoesNotThrow(async () => await prec.sync());
+  await assertDoesNotThrow(async () => await prec.submit());
+
+  t.equal(prec.name, 'PREC-1002', 'PREC name matches');
+  t.equal(pinv.stockNotTransferred, 0, 'stock has been transferred');
+  t.equal(pinv.items?.[0].stockNotTransferred, 0, 'stock has been transferred');
+});
+
+test('Back Ref Purchase Receipt cancel', async (t) => {
+  const prec = (await fyo.doc.getDoc(
+    ModelNameEnum.PurchaseReceipt,
+    'PREC-1002'
+  )) as StockTransfer;
+
+  t.equal(prec.backReference, 'PINV-1001', 'back reference matches');
+  await assertDoesNotThrow(async () => {
+    await prec.cancel();
+  });
+
+  const pinv = (await fyo.doc.getDoc(
+    ModelNameEnum.PurchaseInvoice,
+    'PINV-1001'
+  )) as Invoice;
+
+  t.equal(pinv.stockNotTransferred, 3, 'pinv stock untransferred');
+  t.equal(
+    pinv.items?.[0].stockNotTransferred,
+    3,
+    'pinv item stock untransferred'
+  );
+});
+
+test('Cancel Purchase Invoice after Purchase Receipt is created', async (t) => {
+  const pinv = (await fyo.doc.getDoc(
+    ModelNameEnum.PurchaseInvoice,
+    'PINV-1001'
+  )) as Invoice;
+
+  const prec = await pinv.getStockTransfer();
+  if (prec === null) {
+    return t.ok(false, 'prec was null');
+  }
+
+  prec.date = new Date('2022-01-05');
+  await prec.sync();
+  await prec.submit();
+
+  t.equal(prec.name, 'PREC-1003', 'PREC name matches');
+  t.equal(prec.backReference, 'PINV-1001', 'PREC backref matches');
+
+  await assertThrows(async () => {
+    await pinv.cancel();
+  }, 'cancel prevented cause of PREC');
+
+  const ales = await fyo.db.getAllRaw(ModelNameEnum.AccountingLedgerEntry, {
+    fields: ['name', 'reverted'],
+    filters: { referenceName: pinv.name!, reverted: true },
+  });
+
+  t.equal(ales.length, 0);
+});
+
+test('Sales Invoice then partial Shipment', async (t) => {
+  const rate = testDocs.Item[item].rate as number;
+  const sinv = fyo.doc.getNewDoc(ModelNameEnum.SalesInvoice) as Invoice;
+
+  await sinv.set({
+    party,
+    date: new Date('2022-01-06'),
+    account: 'Debtors',
+  });
+  await sinv.append('items', { item, quantity: 3, rate });
+  await sinv.sync();
+  await sinv.submit();
+
+  t.equal(sinv.name, 'SINV-1001', 'SINV name matches');
+  t.equal(sinv.stockNotTransferred, 3, 'stock not transferred');
+
+  const shpm = await sinv.getStockTransfer();
+  if (shpm === null) {
+    return t.ok(false, 'shpm was null');
+  }
+
+  shpm.date = new Date('2022-01-07');
+  await shpm.items?.[0].set('quantity', 1);
+
+  await assertDoesNotThrow(async () => await shpm.sync());
+  await assertDoesNotThrow(async () => await shpm.submit());
+
+  t.equal(ModelNameEnum.Shipment, shpm.schemaName, 'stock transfer is a SHPM');
+  t.equal(shpm.backReference, sinv.name, 'back reference is set');
+  t.equal(shpm.items?.[0].quantity, 1, 'shpm transfers quantity 1');
+
+  t.equal(shpm.name, 'SHPM-1003', 'SHPM name matches');
+  t.equal(sinv.stockNotTransferred, 2, 'stock qty 2 has not been transferred');
+  t.equal(
+    sinv.items?.[0].stockNotTransferred,
+    2,
+    'item stock qty 2 has not been transferred'
+  );
+});
+
+test('Sales Invoice then another Shipment', async (t) => {
+  const sinv = (await fyo.doc.getDoc(
+    ModelNameEnum.SalesInvoice,
+    'SINV-1001'
+  )) as Invoice;
+
+  const shpm = await sinv.getStockTransfer();
+  if (shpm === null) {
+    return t.ok(false, 'shpm was null');
+  }
+
+  await assertDoesNotThrow(async () => await shpm.sync());
+  await assertDoesNotThrow(async () => await shpm.submit());
+
+  t.equal(shpm.name, 'SHPM-1004', 'SHPM name matches');
+  t.equal(shpm.items?.[0].quantity, 2, 'shpm transfers quantity 2');
+  t.equal(sinv.stockNotTransferred, 0, 'stock has been transferred');
+  t.equal(
+    sinv.items?.[0].stockNotTransferred,
+    0,
+    'item stock has been transferred'
+  );
+  t.equal(await sinv.getStockTransfer(), null, 'no more stock transfers');
+});
+
+test('Cancel Sales Invoice after Shipment is created', async (t) => {
+  const sinv = (await fyo.doc.getDoc(
+    ModelNameEnum.SalesInvoice,
+    'SINV-1001'
+  )) as Invoice;
+  await assertThrows(
+    async () => await sinv.cancel(),
+    'cancel prevent cause of SHPM'
+  );
+
+  const ales = await fyo.db.getAllRaw(ModelNameEnum.AccountingLedgerEntry, {
+    fields: ['name', 'reverted'],
+    filters: { referenceName: sinv.name!, reverted: true },
+  });
+
+  t.equal(ales.length, 0);
+});
+
+test('Cancel partial Shipment', async (t) => {
+  let shpm = (await fyo.doc.getDoc(
+    ModelNameEnum.Shipment,
+    'SHPM-1003'
+  )) as StockTransfer;
+
+  t.equal(shpm.backReference, 'SINV-1001', 'SHPM 1 back ref is set');
+  t.equal(shpm.items?.[0].quantity, 1, 'SHPM transfers qty 1');
+
+  await assertDoesNotThrow(async () => await shpm.cancel());
+  t.ok(shpm.isCancelled, 'SHPM cancelled');
+
+  const sinv = (await fyo.doc.getDoc(
+    ModelNameEnum.SalesInvoice,
+    'SINV-1001'
+  )) as Invoice;
+  t.equal(sinv.stockNotTransferred, 1, 'stock qty 1 untransferred');
+
+  shpm = (await fyo.doc.getDoc(
+    ModelNameEnum.Shipment,
+    'SHPM-1004'
+  )) as StockTransfer;
+
+  t.equal(shpm.backReference, 'SINV-1001', 'SHPM 2 back ref is set');
+  t.equal(shpm.items?.[0].quantity, 2, 'SHPM transfers qty 2');
+
+  await assertDoesNotThrow(async () => await shpm.cancel());
+  t.ok(shpm.isCancelled, 'SHPM cancelled');
+
+  t.equal(sinv.stockNotTransferred, 3, 'all stock untransferred');
+});
+
+test('Duplicate Shipment, backref unset', async (t) => {
+  const shpm = (await fyo.doc.getDoc(
+    ModelNameEnum.Shipment,
+    'SHPM-1003'
+  )) as StockTransfer;
+
+  t.ok(shpm.backReference, 'SHPM back ref is set');
+
+  const doc = shpm.duplicate();
+  t.notOk(doc.backReference, 'Duplicate SHPM back ref is not set');
+});
+
+test('Cancel and Delete Sales Invoice with cancelled Shipments', async (t) => {
+  const sinv = (await fyo.doc.getDoc(
+    ModelNameEnum.SalesInvoice,
+    'SINV-1001'
+  )) as Invoice;
+
+  await assertDoesNotThrow(async () => await sinv.cancel());
+  t.ok(sinv.isCancelled, 'sinv cancelled');
+
+  const transfers = (await fyo.db.getAllRaw(ModelNameEnum.Shipment, {
+    fields: ['name'],
+    filters: { backReference: 'SINV-1001' },
+  })) as { name: string }[];
+
+  await assertDoesNotThrow(async () => await sinv.delete());
+  t.notOk(
+    await fyo.db.exists(ModelNameEnum.SalesInvoice, 'SINV-1001'),
+    'SINV-1001 deleted'
+  );
+
+  for (const { name } of transfers) {
+    t.notOk(
+      await fyo.db.exists(ModelNameEnum.Shipment, 'SINV-1001'),
+      `linked Shipment ${name} deleted`
+    );
+  }
+});
+
 closeTestFyo(fyo, __filename);