diff --git a/web/src/services/api/correctionsFake.test.ts b/web/src/services/api/correctionsFake.test.ts
index e61d7bd..f22d7cf 100644
--- a/web/src/services/api/correctionsFake.test.ts
+++ b/web/src/services/api/correctionsFake.test.ts
@@ -74,13 +74,61 @@ describe('correctionsFake', () => {
 		const u = t0.unallocated[0];
 		const t1 = await fake.allocate(V, { statement_type: 'balance', entry_ids: u.entry_ids, action: 'ASSIGN', rule_id: 'r7' });
 		expect(t1.unallocated).toHaveLength(t0.unallocated.length - 1);
+		// строка кредитовая (K): владелец — компания 2, контрагент — компания 1, строка в side_2
+		expect(u.side).toBe('K');
 		const created = t1.aggregates.find((a) => a.rule_id === 'r7');
-		expect(created?.side_1.amount).toBe(u.amount);
+		expect(created?.company_2.name).toBe('ООО "БСК"');
+		expect(created?.company_1.name).toBe('ПМП ООО');
+		expect(created?.side_2.amount).toBe(u.amount);
+		expect(created?.side_1.entries).toEqual([]);
 		const t2 = await fake.allocate(V, { statement_type: 'balance', entry_ids: u.entry_ids, action: 'UNASSIGN' });
 		expect(t2.aggregates.find((a) => a.rule_id === 'r7')).toBeUndefined();
 		expect(t2.unallocated.find((x) => x.entry_ids[0] === u.entry_ids[0])?.reason).toBe('UNASSIGNED');
 	});
 
+	it('ASSIGN без rule_id и неизвестная строка', async () => {
+		const u = (await fake.getCorrectionTable(V)).unallocated[0];
+		await expectCode(fake.allocate(V, { statement_type: 'balance', entry_ids: u.entry_ids, action: 'ASSIGN' }), 422, 'RULE_REQUIRED');
+		await expectCode(fake.allocate(V, { statement_type: 'balance', entry_ids: ['нет'], action: 'EXCLUDE' }), 422, 'ENTRY_NOT_IN_VERSION');
+	});
+
+	it('allocate атомарен: ошибка на второй строке откатывает первую', async () => {
+		const t = await fake.getCorrectionTable(V);
+		const first = t.unallocated[0].entry_ids[0];
+		await expectCode(fake.allocate(V, { statement_type: 'balance', entry_ids: [first, 'нет'], action: 'EXCLUDE' }), 422, 'ENTRY_NOT_IN_VERSION');
+		expect((await fake.getCorrectionTable(V)).unallocated[0].excluded).toBe(false);
+	});
+
+	it('перенос между правилами возвращает прежнее правило в кандидаты', async () => {
+		const t = await fake.getCorrectionTable(V);
+		const row = find(t, 'ООО "БЕКОВСКИЙ САХАРНЫЙ ЗАВОД"').side_1.entries.find((e) => e.account_code === '62.03');
+		if (!row) throw new Error('нет строки');
+		const moved = await fake.allocate(V, { statement_type: 'balance', entry_ids: row.entry_ids, action: 'ASSIGN', rule_id: 'r7' });
+		const target = moved.aggregates.find((a) => a.rule_id === 'r7');
+		const e = target?.side_1.entries[0];
+		expect(e?.decision).toBe('ASSIGN');
+		expect(e?.candidate_rule_ids).toContain('r6');
+		expect(e?.candidate_rule_ids).not.toContain('r7');
+	});
+
+	it('INCLUDE возвращает строку, RESET сбрасывает решение', async () => {
+		const t = await fake.getCorrectionTable(V);
+		const row = find(t, 'ООО "БЕКОВСКИЙ САХАРНЫЙ ЗАВОД"').side_1.entries[0];
+		await fake.allocate(V, { statement_type: 'balance', entry_ids: row.entry_ids, action: 'EXCLUDE' });
+		const back = await fake.allocate(V, { statement_type: 'balance', entry_ids: row.entry_ids, action: 'INCLUDE' });
+		expect(find(back, 'ООО "БЕКОВСКИЙ САХАРНЫЙ ЗАВОД"').side_1.amount).toBe('1675000.00');
+		await fake.allocate(V, { statement_type: 'balance', entry_ids: row.entry_ids, action: 'EXCLUDE' });
+		const reset = await fake.allocate(V, { statement_type: 'balance', entry_ids: row.entry_ids, action: 'RESET' });
+		expect(find(reset, 'ООО "БЕКОВСКИЙ САХАРНЫЙ ЗАВОД"').side_1.entries[0].excluded).toBe(false);
+	});
+
+	it('агрегат с одной стороной: ONE_SIDED, порог превышен', async () => {
+		const a = find(await fake.getCorrectionTable(V), 'Агро-Холдинг');
+		expect(a.status).toBe('ONE_SIDED');
+		expect(a.exceeds_threshold).toBe(true);
+		expect(a.deviation_percent).toBeNull();
+	});
+
 	it('saveCorrection: комментарий обязателен, версия проверяется', async () => {
 		const t = await fake.getCorrectionTable(V);
 		const key = toAggregateKey(find(t, 'ООО "БСК"'));
diff --git a/web/src/services/api/correctionsFake.ts b/web/src/services/api/correctionsFake.ts
index 2c3a8f0..76faf92 100644
--- a/web/src/services/api/correctionsFake.ts
+++ b/web/src/services/api/correctionsFake.ts
@@ -58,7 +58,7 @@ function locate(id: string): Located {
 	}
 	const item = state.unallocated.find((u) => u.entry_ids.includes(id));
 	if (item) return { where: 'unallocated', item };
-	return fail(404, 'NOT_FOUND', 'Строка не найдена');
+	return fail(422, 'ENTRY_NOT_IN_VERSION', 'Строки нет среди строк версии');
 }
 
 function refOf(a: CorrectionAggregateOut, id: string): Ref {
@@ -81,7 +81,8 @@ function detach(found: Located): { owner: Ref; counterparty: Ref; account_code:
 		side: e.side,
 		amount: e.amount,
 		entry_ids: e.entry_ids,
-		candidates: e.candidate_rule_ids,
+		// прежнее правило становится одним из кандидатов, как при UNASSIGN
+		candidates: [...new Set([...e.candidate_rule_ids, a.rule_id])],
 		excluded: e.excluded,
 	};
 	touch(a);
@@ -90,21 +91,23 @@ function detach(found: Located): { owner: Ref; counterparty: Ref; account_code:
 }
 
 function assign(found: Located, ruleId: string): void {
-	const rule = state.rules.find((r) => r.id === ruleId);
+	const rule = state.rules.find((r) => r.id === ruleId) ?? fail(404, 'NOT_FOUND', 'Правило не найдено');
 	const candidates = found.where === 'unallocated' ? found.item.candidate_rule_ids : found.entry.candidate_rule_ids;
-	if (!rule || !candidates.includes(ruleId)) fail(422, 'RULE_NOT_APPLICABLE', 'Строка не подходит под это правило');
+	if (!candidates.includes(ruleId)) fail(422, 'RULE_NOT_APPLICABLE', 'Строка не подходит под это правило');
 	const moved = detach(found);
-	let target = state.aggregates.find(
-		(a) => a.rule_id === ruleId && [a.company_1.id, a.company_2.id].includes(moved.owner.id) && [a.company_1.id, a.company_2.id].includes(moved.counterparty.id),
-	);
+	// Сторона 1 правила — дебетовая: строка с этой стороной принадлежит компании 1, кредитовая — компании 2.
+	const isSide1 = moved.side === rule.side_1;
+	const c1 = isSide1 ? moved.owner : moved.counterparty;
+	const c2 = isSide1 ? moved.counterparty : moved.owner;
+	let target = state.aggregates.find((a) => a.rule_id === ruleId && a.company_1.id === c1.id && a.company_2.id === c2.id);
 	if (!target) {
 		target = {
 			rule_id: ruleId,
-			rule_no: rule?.rule_no ?? 0,
-			company_1: moved.owner,
-			company_2: moved.counterparty,
-			side_1: { article_line: rule?.article_1_line ?? '', accounts: [], amount: '0.00', entries: [] },
-			side_2: { article_line: rule?.article_2_line ?? '', accounts: [], amount: '0.00', entries: [] },
+			rule_no: rule.rule_no,
+			company_1: c1,
+			company_2: c2,
+			side_1: { article_line: rule.article_1_line, accounts: [], amount: '0.00', entries: [] },
+			side_2: { article_line: rule.article_2_line, accounts: [], amount: '0.00', entries: [] },
 			deviation_amount: '0.00',
 			deviation_percent: null,
 			exceeds_threshold: false,
@@ -126,7 +129,7 @@ function assign(found: Located, ruleId: string): void {
 		excluded: moved.excluded,
 		candidate_rule_ids: moved.candidates.filter((id) => id !== ruleId),
 	};
-	(target.company_1.id === moved.owner.id ? target.side_1 : target.side_2).entries.push(entry);
+	(isSide1 ? target.side_1 : target.side_2).entries.push(entry);
 	touch(target);
 }
 
@@ -147,7 +150,7 @@ function applyAction(id: string, body: AllocationIn): void {
 			flag(false);
 			break;
 		case 'ASSIGN':
-			if (!body.rule_id) fail(422, 'RULE_NOT_APPLICABLE', 'Не указано правило');
+			if (!body.rule_id) fail(422, 'RULE_REQUIRED', 'Для ASSIGN нужно правило');
 			assign(found, body.rule_id as string);
 			break;
 		case 'UNASSIGN': {
@@ -160,7 +163,7 @@ function applyAction(id: string, body: AllocationIn): void {
 				account_code: moved.account_code,
 				side: moved.side,
 				amount: moved.amount,
-				candidate_rule_ids: [...new Set([...moved.candidates, found.aggregate.rule_id])],
+				candidate_rule_ids: moved.candidates,
 				reason: 'UNASSIGNED',
 				excluded: moved.excluded,
 			});
@@ -219,11 +222,19 @@ export const correctionsFake = {
 	allocate(_versionId: string, body: AllocationIn): Promise<CorrectionTableOut> {
 		return run(() => {
 			if (!body.entry_ids.length) fail(422, 'VALIDATION_ERROR', 'Не указаны строки');
-			for (const id of body.entry_ids) applyAction(id, body);
+			// всё или ничего: при ошибке на любой строке возвращаем состояние, каким оно было
+			const backup = clone(state);
+			try {
+				for (const id of body.entry_ids) applyAction(id, body);
+			} catch (e) {
+				state = backup;
+				throw e;
+			}
 			return snapshot();
 		});
 	},
 
+	// CSV-заглушка вместо xlsx сервера: проверяет только скачивание.
 	exportCorrectionTable(_versionId: string): Promise<{ blob: Blob; filename: string | null }> {
 		const rows = state.aggregates.map((a) => [a.company_1.name, a.company_2.name, a.side_1.amount, a.side_2.amount, a.deviation_amount].join(';'));
 		return Promise.resolve({ blob: new Blob([`${rows.join('\n')}`], { type: 'text/csv;charset=utf-8' }), filename: 'corrections-mock.csv' });
diff --git a/web/src/widgets/CorrectionTable/mockCalc.test.ts b/web/src/widgets/CorrectionTable/mockCalc.test.ts
new file mode 100644
index 0000000..96cb78d
--- /dev/null
+++ b/web/src/widgets/CorrectionTable/mockCalc.test.ts
@@ -0,0 +1,12 @@
+import { describe, expect, it } from 'vitest';
+import { percentOfSmaller } from './mockCalc';
+
+describe('percentOfSmaller', () => {
+	it('округляет половину вверх', () => {
+		expect(percentOfSmaller('9.00', '8.00')).toBe('12.50');
+		expect(percentOfSmaller('1.00', '3.00')).toBe('200.00');
+		// отклонение 0.01 к 8.00 = 0.125 % -> 0.13 (половина вверх)
+		expect(percentOfSmaller('8.01', '8.00')).toBe('0.13');
+		expect(percentOfSmaller('0.00', '5.00')).toBeNull();
+	});
+});
diff --git a/web/src/widgets/CorrectionTable/mockCalc.ts b/web/src/widgets/CorrectionTable/mockCalc.ts
index 2541f14..5de9b80 100644
--- a/web/src/widgets/CorrectionTable/mockCalc.ts
+++ b/web/src/widgets/CorrectionTable/mockCalc.ts
@@ -1,10 +1,11 @@
 import type { AggregateSideOut, CorrectionAggregateOut, CorrectionBalanceOut, CorrectionTotalsOut, Money, Percent } from '../../types/corrections';
+import { sumAmounts } from '../../utils/money';
 // Пересчёт агрегата таблицы корректировок — общий для данных фейка и самого фейка. Деньги — строки, арифметика — BigInt-копейки.
 // Это же делает сервер (контракт, раздел 4); на экране эти функции не используются: фронт только показывает ответ.
-import { sumAmounts } from '../../utils/money';
 
 export const THRESHOLD_PERCENT_HUNDREDTHS = 500n;
 
+// toCents/fromCents дублируют BigInt-разбор из utils/money.ts: там он не экспортируется, а правка утилиты вне объёма задачи.
 export function toCents(value: Money): bigint {
 	const match = /^(-?)(\d+)(?:\.(\d{1,2}))?$/.exec(value);
 	if (!match) throw new Error(`Не сумма: ${value}`);