diff --git a/conservancy_beancount/plugin/core.py b/conservancy_beancount/plugin/core.py
index 7733368..7817859 100644
--- a/conservancy_beancount/plugin/core.py
+++ b/conservancy_beancount/plugin/core.py
@@ -24,6 +24,7 @@ from .. import errors as errormod
 
 from typing import (
     Any,
+    Container,
     Dict,
     FrozenSet,
     Generic,
@@ -176,9 +177,10 @@ class MetadataEnum:
 
 class TransactionHook(Hook[Transaction]):
     DIRECTIVE = Transaction
+    SKIP_FLAGS: Container[str] = frozenset()
     TXN_DATE_RANGE: _GenericRange = _GenericRange(DEFAULT_START_DATE, DEFAULT_STOP_DATE)
 
-    def _run_on_txn(self, txn: Transaction, skip_flags: str='!') -> bool:
+    def _run_on_txn(self, txn: Transaction) -> bool:
         """Check whether we should run on a given transaction
 
         This method implements our usual checks for whether or not a hook
@@ -186,7 +188,7 @@ class TransactionHook(Hook[Transaction]):
         their own implementations. See _PostingHook below for an example.
         """
         return (
-            txn.flag not in skip_flags
+            txn.flag not in self.SKIP_FLAGS
             and txn.date in self.TXN_DATE_RANGE
             and not data.is_opening_balance_txn(txn)
         )
diff --git a/conservancy_beancount/plugin/meta_approval.py b/conservancy_beancount/plugin/meta_approval.py
index 3158e5b..169cc4f 100644
--- a/conservancy_beancount/plugin/meta_approval.py
+++ b/conservancy_beancount/plugin/meta_approval.py
@@ -26,13 +26,14 @@ from ..beancount_types import (
 
 class MetaApproval(core._RequireLinksPostingMetadataHook):
     CHECKED_METADATA = ['approval']
+    SKIP_FLAGS = '!'
 
     def __init__(self, config: configmod.Config) -> None:
         self.payment_threshold = -config.payment_threshold()
 
-    def _run_on_txn(self, txn: Transaction, skip_flags: str='!') -> bool:
+    def _run_on_txn(self, txn: Transaction) -> bool:
         return (
-            super()._run_on_txn(txn, skip_flags)
+            super()._run_on_txn(txn)
             # approval is required when funds leave a cash equivalent asset,
             # UNLESS that transaction is a transfer to another asset,
             # or paying off a credit card.
diff --git a/conservancy_beancount/plugin/meta_entity.py b/conservancy_beancount/plugin/meta_entity.py
index 10827e2..1e4ea02 100644
--- a/conservancy_beancount/plugin/meta_entity.py
+++ b/conservancy_beancount/plugin/meta_entity.py
@@ -67,7 +67,7 @@ class MetaEntity(core.TransactionHook):
             return entity, self.ENTITY_RE.match(entity) is not None
 
     def run(self, txn: Transaction) -> errormod.Iter:
-        if not self._run_on_txn(txn, ''):
+        if not self._run_on_txn(txn):
             return
         txn_entity, txn_entity_ok = self._check_entity(txn.meta, txn.payee)
         if txn_entity_ok is False:
diff --git a/conservancy_beancount/plugin/meta_invoice.py b/conservancy_beancount/plugin/meta_invoice.py
index 1c1c09c..d7fb6ba 100644
--- a/conservancy_beancount/plugin/meta_invoice.py
+++ b/conservancy_beancount/plugin/meta_invoice.py
@@ -24,6 +24,7 @@ from ..beancount_types import (
 
 class MetaInvoice(core._RequireLinksPostingMetadataHook):
     CHECKED_METADATA = ['invoice']
+    SKIP_FLAGS = '!'
 
     def _run_on_post(self, txn: Transaction, post: data.Posting) -> bool:
         return post.account.is_under(
diff --git a/conservancy_beancount/plugin/meta_payable_documentation.py b/conservancy_beancount/plugin/meta_payable_documentation.py
index fd37651..4102b72 100644
--- a/conservancy_beancount/plugin/meta_payable_documentation.py
+++ b/conservancy_beancount/plugin/meta_payable_documentation.py
@@ -24,6 +24,7 @@ from ..beancount_types import (
 
 class MetaPayableDocumentation(core._RequireLinksPostingMetadataHook):
     CHECKED_METADATA = ['approval', 'contract']
+    SKIP_FLAGS = '!'
 
     def _run_on_post(self, txn: Transaction, post: data.Posting) -> bool:
         if post.account.is_under('Liabilities:Payable:Accounts'):
diff --git a/conservancy_beancount/plugin/meta_project.py b/conservancy_beancount/plugin/meta_project.py
index 982b893..0014706 100644
--- a/conservancy_beancount/plugin/meta_project.py
+++ b/conservancy_beancount/plugin/meta_project.py
@@ -102,7 +102,7 @@ class MetaProject(core._NormalizePostingMetadataHook):
         else:
             raise errormod.InvalidMetadataError(txn, self.METADATA_KEY, None, post)
 
-    def _run_on_txn(self, txn: Transaction, skip_flags: str='') -> bool:
+    def _run_on_txn(self, txn: Transaction) -> bool:
         return txn.date in self.TXN_DATE_RANGE
 
     def run(self, txn: Transaction) -> errormod.Iter:
diff --git a/conservancy_beancount/plugin/meta_receipt.py b/conservancy_beancount/plugin/meta_receipt.py
index 4c2c9b9..c679020 100644
--- a/conservancy_beancount/plugin/meta_receipt.py
+++ b/conservancy_beancount/plugin/meta_receipt.py
@@ -31,6 +31,7 @@ from typing import (
 
 class MetaReceipt(core._RequireLinksPostingMetadataHook):
     CHECKED_METADATA = ['receipt']
+    SKIP_FLAGS = '!'
 
     def __init__(self, config: configmod.Config) -> None:
         self.payment_threshold = abs(config.payment_threshold())
diff --git a/conservancy_beancount/plugin/meta_receivable_documentation.py b/conservancy_beancount/plugin/meta_receivable_documentation.py
index df7c21b..02c5a43 100644
--- a/conservancy_beancount/plugin/meta_receivable_documentation.py
+++ b/conservancy_beancount/plugin/meta_receivable_documentation.py
@@ -41,6 +41,7 @@ class MetaReceivableDocumentation(core._RequireLinksPostingMetadataHook):
     ISSUED_INVOICE_RE = re.compile(
         r'[Ii]nvoice[-_ ]*(?:2[0-9]{9,}|30[0-9]+)[A-Za-z]*[-_ .]',
     )
+    SKIP_FLAGS = '!'
 
     def __init__(self, config: configmod.Config) -> None:
         rt_wrapper = config.rt_wrapper()
diff --git a/conservancy_beancount/plugin/meta_repo_links.py b/conservancy_beancount/plugin/meta_repo_links.py
index 3c68cfc..fdf1fc2 100644
--- a/conservancy_beancount/plugin/meta_repo_links.py
+++ b/conservancy_beancount/plugin/meta_repo_links.py
@@ -36,6 +36,7 @@ class MetaRepoLinks(core.TransactionHook):
     HOOK_GROUPS = frozenset(['linkcheck'])
     LINK_METADATA = data.LINK_METADATA.difference('rt-id')
     PATH_PUNCT_RE = re.compile(r'[:/]')
+    SKIP_FLAGS = '!'
 
     def __init__(self, config: configmod.Config) -> None:
         repo_path = config.repository_path()
diff --git a/conservancy_beancount/plugin/meta_rt_links.py b/conservancy_beancount/plugin/meta_rt_links.py
index 57cc114..95e4fc8 100644
--- a/conservancy_beancount/plugin/meta_rt_links.py
+++ b/conservancy_beancount/plugin/meta_rt_links.py
@@ -32,6 +32,7 @@ from typing import (
 
 class MetaRTLinks(core.TransactionHook):
     HOOK_GROUPS = frozenset(['linkcheck', 'network', 'rt'])
+    SKIP_FLAGS = '!'
 
     def __init__(self, config: configmod.Config) -> None:
         rt_wrapper = config.rt_wrapper()
diff --git a/conservancy_beancount/plugin/meta_tax_implication.py b/conservancy_beancount/plugin/meta_tax_implication.py
index 3dc5839..b14144d 100644
--- a/conservancy_beancount/plugin/meta_tax_implication.py
+++ b/conservancy_beancount/plugin/meta_tax_implication.py
@@ -39,6 +39,9 @@ class MetaTaxImplication(core._NormalizePostingMetadataHook):
         'USA-Corporation',
         'W2',
     ])
+    # Sometimes we accrue a payment before we have determined the recipient's
+    # tax status.
+    SKIP_FLAGS = '!'
 
     def __init__(self, config: configmod.Config) -> None:
         self.payment_threshold = -config.payment_threshold()
diff --git a/tests/test_meta_entity.py b/tests/test_meta_entity.py
index e077a57..cf491b0 100644
--- a/tests/test_meta_entity.py
+++ b/tests/test_meta_entity.py
@@ -226,3 +226,10 @@ def test_required_by_date(hook, date, need_value):
         ('Assets:Checking', 10),
     ])
     assert any(hook.run(txn)) == need_value
+
+def test_still_required_on_flagged(hook):
+    txn = testutil.Transaction(flag='!', postings=[
+        ('Income:Donations', -10),
+        ('Assets:Checking', 10),
+    ])
+    assert list(hook.run(txn))
diff --git a/tests/test_meta_expense_allocation.py b/tests/test_meta_expense_allocation.py
index af081d9..6f712bb 100644
--- a/tests/test_meta_expense_allocation.py
+++ b/tests/test_meta_expense_allocation.py
@@ -132,3 +132,13 @@ def test_default_value_set_in_date_range(hook, date, set_value):
     assert not errors
     expect_meta = None if set_value is None else {TEST_KEY: set_value}
     testutil.check_post_meta(txn, None, expect_meta)
+
+@pytest.mark.parametrize('src_value', INVALID_VALUES)
+def test_flagged_txn_checked(hook, src_value):
+    txn = testutil.Transaction(flag='!', postings=[
+        ('Assets:Cash', -25),
+        ('Expenses:General', 25, {TEST_KEY: src_value}),
+    ])
+    errors = list(hook.run(txn))
+    assert errors
+    testutil.check_post_meta(txn, None, {TEST_KEY: src_value})
diff --git a/tests/test_meta_income_type.py b/tests/test_meta_income_type.py
index 0260bf0..41bde2a 100644
--- a/tests/test_meta_income_type.py
+++ b/tests/test_meta_income_type.py
@@ -149,3 +149,13 @@ def test_default_value_set_in_date_range(hook, date, set_value):
     assert not errors
     expect_meta = None if set_value is None else {TEST_KEY: set_value}
     testutil.check_post_meta(txn, None, expect_meta)
+
+@pytest.mark.parametrize('src_value', INVALID_VALUES)
+def test_flagged_txn_checked(hook, src_value):
+    txn = testutil.Transaction(flag='!', postings=[
+        ('Assets:Cash', 25),
+        ('Income:Other', -25, {TEST_KEY: src_value}),
+    ])
+    errors = list(hook.run(txn))
+    assert errors
+    testutil.check_post_meta(txn, None, {TEST_KEY: src_value})
diff --git a/tests/test_meta_paypal_id.py b/tests/test_meta_paypal_id.py
index 49d736e..0860332 100644
--- a/tests/test_meta_paypal_id.py
+++ b/tests/test_meta_paypal_id.py
@@ -194,3 +194,10 @@ def test_not_required_on_opening(hook):
         (next(testutil.OPENING_EQUITY_ACCOUNTS), -1000),
     ])
     assert not list(hook.run(txn))
+
+def test_still_required_on_flagged_txn(hook):
+    txn = testutil.Transaction(flag='!', postings=[
+        ('Assets:PayPal', 1000),
+        ('Income:Donations', -1000),
+    ])
+    assert list(hook.run(txn))
diff --git a/tests/test_meta_project.py b/tests/test_meta_project.py
index 8c84fcf..6178f68 100644
--- a/tests/test_meta_project.py
+++ b/tests/test_meta_project.py
@@ -166,3 +166,13 @@ def test_always_required_on_restricted_funds(hook):
     txn = testutil.OpeningBalance(acct)
     actual = {error.message for error in hook.run(txn)}
     assert actual == {f'{acct} missing project'}
+
+@pytest.mark.parametrize('src_value', INVALID_VALUES)
+def test_still_required_on_flagged_txn(hook, src_value):
+    txn = testutil.Transaction(flag='!', **{TEST_KEY: src_value}, postings=[
+        ('Assets:Cash', -25),
+        ('Expenses:General', 25),
+    ])
+    errors = list(hook.run(txn))
+    assert errors
+    testutil.check_post_meta(txn, None, None)
diff --git a/tests/test_meta_tax_implication.py b/tests/test_meta_tax_implication.py
index 88aa69f..8d490ca 100644
--- a/tests/test_meta_tax_implication.py
+++ b/tests/test_meta_tax_implication.py
@@ -135,3 +135,11 @@ def test_validation_only_in_date_range(hook, date, need_value):
     errors = list(hook.run(txn))
     assert bool(errors) == bool(need_value)
     testutil.check_post_meta(txn, None, None)
+
+@pytest.mark.parametrize('src_value', INVALID_VALUES)
+def test_flagged_txn_skipped(hook, src_value):
+    txn = testutil.Transaction(flag='!', **{TEST_KEY: src_value}, postings=[
+        ('Liabilities:Payable:Accounts', 25),
+        ('Assets:Cash', -25),
+    ])
+    assert not list(hook.run(txn))