--- a/src/file-storage/internal/XmlBudgetFile.cpp	Mon Oct 03 19:37:42 2022 +0200
+++ b/src/file-storage/internal/XmlBudgetFile.cpp	Wed Oct 05 18:05:26 2022 +0200
@@ -643,7 +643,8 @@
 					},
 					reconciliationElement.date_
 				},
-				{} // TODO: distribution amounts and validity value
+				{}, // TODO: distribution amounts
+				{} // TODO: validity value
 			}
 		);
 	}

--- a/src/file-storage/unit-tests/BudgetFileContents.cpp	Mon Oct 03 19:37:42 2022 +0200
+++ b/src/file-storage/unit-tests/BudgetFileContents.cpp	Wed Oct 05 18:05:26 2022 +0200
@@ -687,12 +687,13 @@
 						Money{1234, 5600u, Iso4217Codes::PLN},
 						QDate{2022, 8, 31}
 					},
+					{},
 					{}
 				}
 			},
 			{
 				c1stSavings,
-				ReconciledSurvey{ReconciledBankAccount{c1stSavings, Iso4217Codes::PLN}, {}}
+				ReconciledSurvey{c1stSavings, Iso4217Codes::PLN}
 			}
 		}
 	};

--- a/src/navigation/internal/BudgetBankLedgers.cpp	Mon Oct 03 19:37:42 2022 +0200
+++ b/src/navigation/internal/BudgetBankLedgers.cpp	Wed Oct 05 18:05:26 2022 +0200
@@ -928,13 +928,9 @@
 
 	try
 	{
-		this->surveys_.completed(
-			ReconciledSurvey{
-				ReconciledBankAccount{ba, reconciledBalance, completedOn},
-				unusedBudget
-			},
-			reconciledBalance
-		);
+		auto survey{previousSurvey.valueOr(ReconciledSurvey{ba, ledger.account_.balance().code()})};
+		survey.completed(completedOn, reconciledBalance, unusedBudget);
+		this->surveys_.upsert(survey);
 	}
 	catch (const exception&)
 	{

--- a/src/surveying/external/surveying/ReconciledSurvey.cpp	Mon Oct 03 19:37:42 2022 +0200
+++ b/src/surveying/external/surveying/ReconciledSurvey.cpp	Wed Oct 05 18:05:26 2022 +0200
@@ -29,6 +29,8 @@
 using drn::surveying::ReconciledSurvey;
 using drn::surveying::ReconciledSurveys;
 
+#include <pecunia/Codes.h>
+using pecunia::currency::Iso4217Codes;
 #include <pecunia/Math.h>
 using pecunia::math::sum;
 #include <QCryptographicHash>
@@ -65,15 +67,17 @@
 {
 
 QString calculateValidity(
-	ReconciledBankAccount reconciled,
-	map<BudgetItemIdentifier, Money> distribution
+	const BankAccount& ba,
+	const Money& balance,
+	const Optional<QDate>& reconciledOn,
+	const map<BudgetItemIdentifier, Money>& distribution
 )
 {
-	QString value{presentationText(reconciled.bankAccount())};
-	value = value % presentationText(reconciled.balance(), false, true);
+	QString value{presentationText(ba)};
+	value = value % presentationText(balance, false, true);
 
-	if (reconciled.reconciledOn().hasValue())
-		value = value % reconciled.reconciledOn()->toString(DateFormat::ISODate);
+	if (reconciledOn.hasValue())
+		value = value % reconciledOn->toString(DateFormat::ISODate);
 
 	for (const auto& itemAmount : distribution)
 		value = value % presentationText(itemAmount.first)
@@ -85,6 +89,10 @@
 
 //{ ReconciledSurvey
 
+ReconciledSurvey::ReconciledSurvey(BankAccount ba, const Iso4217Codes& currency) :
+	ReconciledSurvey{ReconciledBankAccount{ba, currency}, {}, {}}
+{}
+
 ReconciledSurvey::ReconciledSurvey(
 	ReconciledBankAccount reconciled,
 	map<BudgetItemIdentifier, Money> distribution,
@@ -96,7 +104,14 @@
 {
 	if (this->validity_.hasValue())
 	{
-		const auto validityCheck{calculateValidity(this->reconciled_, this->distribution_)};
+		const auto validityCheck{
+			calculateValidity(
+				this->reconciled_.bankAccount(),
+				this->reconciled_.balance(),
+				this->reconciled_.reconciledOn(),
+				this->distribution_
+			)
+		};
 
 		if (this->validity_ != validityCheck)
 			throw Error{
@@ -123,6 +138,32 @@
 	return this->validity_;
 }
 
+void ReconciledSurvey::completed(
+	const QDate& completedOn,
+	const Money& reconciledBalance,
+	const map<BudgetItemIdentifier, Money>& distribution
+)
+{
+	const auto distributionBalance{sum(this->reconciled_.balance().code(), distribution)};
+	const auto ba{this->reconciled_.bankAccount()};
+
+	if (reconciledBalance != distributionBalance)
+		throw BankError{
+			ba.bank_,
+			QObject::tr("The surveyed balance %1 does not match the unused %2 balance.")
+				.arg(presentationText(reconciledBalance))
+				.arg(presentationText(distributionBalance))
+		};
+// 	this->validity_ = calculateValidity(
+// 		this->reconciled_.bankAccount(),
+// 		reconciledBalance,
+// 		completedOn,
+// 		distribution
+// 	);
+	this->reconciled_.reconcile(completedOn, reconciledBalance);
+	this->distribution_ = move(distribution);
+}
+
 bool drn::surveying::operator==(const ReconciledSurvey& lhs, const ReconciledSurvey& rhs)
 {
 	return tie(lhs.reconciled(), lhs.distribution()) == tie(rhs.reconciled(), rhs.distribution());
@@ -188,24 +229,14 @@
 	return account->second;
 }
 
-void ReconciledSurveys::completed(ReconciledSurvey survey, const Money& reconciledBalance)
+void ReconciledSurveys::upsert(ReconciledSurvey survey)
 {
-	const auto expectedBalance{sum(survey.reconciled().balance().code(), survey.distribution())};
 	const auto ba{survey.reconciled().bankAccount()};
 
-	if (reconciledBalance != expectedBalance)
-		throw BankError{
-			ba.bank_,
-			QObject::tr("The surveyed balance %1 does not match the expected %2.")
-				.arg(presentationText(reconciledBalance))
-				.arg(presentationText(expectedBalance))
-		};
-	// TODO: survey.verification_ = calculateVerification();
-
 	if (this->count(ba) == 0)
 	{
 		const auto emplaced{(*this).emplace(ba, move(survey))};
-		assert(emplaced.second && "The new survey should always be inserted.");
+		assert(emplaced.second && "A new survey should always be inserted.");
 	}
 	else
 		(*this)[ba] = move(survey);

--- a/src/surveying/external/surveying/ReconciledSurvey.h	Mon Oct 03 19:37:42 2022 +0200
+++ b/src/surveying/external/surveying/ReconciledSurvey.h	Wed Oct 05 18:05:26 2022 +0200
@@ -56,16 +56,22 @@
 public:
 	ReconciledSurvey() = default;
 	/**
-	 * @brief Full and partial initialisation constructor.
+	 * @brief Partial initialisation constructor for creating a new survey.
+	 *
+	 * @param ba The bank account that is reconciled.
+	 * @param currency The currency held within the bank account.
+	 */
+	ReconciledSurvey(banking::BankAccount ba, const pecunia::currency::Iso4217Codes& currency);
+	/**
+	 * @brief Full initialisation constructor.
 	 *
 	 * @exception Error When a supplied validity value does not match the calculated value.
 	 *
 	 * @param reconciled The bank account that was reconciled.
 	 * @param distribution The distribution of the balance in the account.
-	 * @param validity When supplied, the value that represents an object whose values were verified
-	 * after having completed a survey. This is in lieu of verifying the balances upon object
-	 * creation since exchange rates change over time. If not supplied, no verification is
-	 * performed, i.e. the object is partially initialised.
+	 * @param validity The value that represents an object whose values were verified after having
+	 * completed a survey. This is in lieu of verifying the balances upon object creation since
+	 * exchange rates change over time preventing verification in the future.
 	 */
 	ReconciledSurvey(
 		banking::ReconciledBankAccount reconciled,
@@ -73,7 +79,7 @@
 			budgeting::BudgetItemIdentifier,
 			pecunia::currency::Money
 		> distribution,
-		foundation::Optional<::QString> validity = {}
+		foundation::Optional<::QString> validity
 	);
 	const banking::ReconciledBankAccount& reconciled() const noexcept;
 	const std::map<
@@ -84,6 +90,23 @@
 	 * @brief The value that represents a valid object after having completed a survey.
 	 */
 	const foundation::Optional<::QString>& validity() const noexcept;
+	/**
+	 * @brief Updates the survey with the completed values.
+	 *
+	 * @exception BankError When the reconciled bank balance does not match the amount of
+	 * distributed unused funds.
+	 *
+	 * @param completedOn The date the balance was confirmed.
+	 * @param reconciledBalance The balance as reported in the bank account.
+	 * @param distribution The distribution of unused funds (bank balance) in the bank account.
+	 *
+	 * @post Upon successful survey completion, the validity value is computed and stored in the object.
+	 */
+	void completed(
+		const ::QDate& completedOn,
+		const pecunia::currency::Money& reconciledBalance,
+		const std::map<budgeting::BudgetItemIdentifier, pecunia::currency::Money>& distribution
+	);
 };
 
 class DRN_SURVEYING_EXPORT ReconciledSurveys : std::map<banking::BankAccount, ReconciledSurvey>
@@ -100,13 +123,12 @@
 	using std::map<banking::BankAccount, ReconciledSurvey>::count;
 	using std::map<banking::BankAccount, ReconciledSurvey>::at;
 	using std::map<banking::BankAccount, ReconciledSurvey>::size;
-
 	foundation::Optional<ReconciledSurvey> find(const banking::BankAccount& ba) const;
 	foundation::Optional<ReconciledSurvey> find(
 		const banking::BankName& bn,
 		const accounting::AccountNumber& an
 	) const;
-	void completed(ReconciledSurvey survey, const pecunia::currency::Money& reconciledBalance);
+	void upsert(ReconciledSurvey survey);
 };
 
 DRN_SURVEYING_EXPORT bool operator==(

--- a/src/surveying/unit-tests/ReconciledSurvey-unit-tests.cpp	Mon Oct 03 19:37:42 2022 +0200
+++ b/src/surveying/unit-tests/ReconciledSurvey-unit-tests.cpp	Wed Oct 05 18:05:26 2022 +0200
@@ -111,9 +111,20 @@
 
 	void constructor_PartialInit_ShouldSet()
 	{
-		const ReconciledSurvey survey{this->reconciled_, this->distribution_};
-		QVERIFY_THAT(survey.distribution(), equals(this->distribution_));
-		QVERIFY_THAT(survey.reconciled(), equals(this->reconciled_));
+		const ReconciledSurvey survey{
+			this->reconciled_.bankAccount(),
+			this->reconciled_.balance().code()
+		};
+		QVERIFY_THAT(
+			survey.reconciled(),
+			equals(
+				ReconciledBankAccount{
+					this->reconciled_.bankAccount(),
+					this->reconciled_.balance().code()
+				}
+			)
+		);
+		QVERIFY_TRUE(survey.distribution().empty());
 		QVERIFY_FALSE(survey.validity().hasValue());
 	}