EX-99.19a-1

MFS® Charter Income Trust

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders Source of distribution

Distribution period

May -2026

Distribution amount per share

$0.04399

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

 

Current

% Breakdown of

Total cumulative

% Breakdown of the total

 

distributions for the

cumulative distributions

 

distribution

current distribution

fiscal year to date

for the fiscal year to date

Net Investment Income

0.01320

30%

0.19268

72%

Net Realized ST Cap Gains

0.00000

0%

0.00000

0%

Net Realized LT Cap Gains

0.00000

0%

0.00000

0%

Return of Capital or

0.03079

70%

0.07493

28%

Other Capital Source

Total (per common share)

0.04399

100%

0.26761

100%

Average annual total return (in relation to NAV) for the five years ended 4-30-2026

3.00%

Annualized current distribution rate expressed as a percentage of month end NAV as of 4-30-2026

8.02%

Cumulative total return (in relation to NAV) for the fiscal year through 4-30-2026

1.07%

Cumulative fiscal year distributions as a percentage of NAV as of 4-30-2026

4.07%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax- reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes.

If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

MCRSN-0526

MFS® Charter Income Trust

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders Source of distribution

Distribution period

April -2026

Distribution amount per share

$0.04396

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

 

Current

% Breakdown of

Total cumulative

% Breakdown of the total

 

distributions for the

cumulative distributions

 

distribution

current distribution

fiscal year to date

for the fiscal year to date

Net Investment Income

0.04396

100%

0.18337

82%

Net Realized ST Cap Gains

0.00000

0%

0.00000

0%

Net Realized LT Cap Gains

0.00000

0%

0.00000

0%

Return of Capital or

0.00000

0%

0.04025

18%

Other Capital Source

Total (per common share)

0.04396

100%

0.22362

100%

Average annual total return (in relation to NAV) for the five years ended 3-31-2026

2.90%

Annualized current distribution rate expressed as a percentage of month end NAV as of 3-31-2026

8.08%

Cumulative total return (in relation to NAV) for the fiscal year through 3-31-2026

-0.42%

Cumulative fiscal year distributions as a percentage of NAV as of 3-31-2026

3.42%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax- reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes.

If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

MCRSN-0426

MFS® Charter Income Trust

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders Source of distribution

Distribution period

March -2026

Distribution amount per share

$0.04495

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

 

Current

% Breakdown of

Total cumulative

% Breakdown of the total

 

distributions for the

cumulative distributions

 

distribution

current distribution

fiscal year to date

for the fiscal year to date

Net Investment Income

0.04001

89%

0.12397

69%

Net Realized ST Cap Gains

0.00000

0%

0.00000

0%

Net Realized LT Cap Gains

0.00000

0%

0.00000

0%

Return of Capital or

0.00494

11%

0.05569

31%

Other Capital Source

Total (per common share)

0.04495

100%

0.17966

100%

Average annual total return (in relation to NAV) for the five years ended 2-28-2026

3.33%

Annualized current distribution rate expressed as a percentage of month end NAV as of 2-28-2026

8.01%

Cumulative total return (in relation to NAV) for the fiscal year through 2-28-2026

1.87%

Cumulative fiscal year distributions as a percentage of NAV as of 2-28-2026

2.67%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax- reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes.

If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

MCRSN-0326

MFS® Charter Income Trust

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders Source of distribution

Distribution period

February -2026

Distribution amount per share

$0.04495

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

 

Current

% Breakdown of

Total cumulative

% Breakdown of the total

 

distributions for the

cumulative distributions

 

distribution

current distribution

fiscal year to date

for the fiscal year to date

Net Investment Income

0.01438

32%

0.08083

60%

Net Realized ST Cap Gains

0.00000

0%

0.00000

0%

Net Realized LT Cap Gains

0.00000

0%

0.00000

0%

Return of Capital or

0.03057

68%

0.05388

40%

Other Capital Source

Total (per common share)

0.04495

100%

0.13471

100%

Average annual total return (in relation to NAV) for the five years ended 1-31-2026

3.00%

Annualized current distribution rate expressed as a percentage of month end NAV as of 1-31-2026

8.03%

Cumulative total return (in relation to NAV) for the fiscal year through 1-31-2026

0.99%

Cumulative fiscal year distributions as a percentage of NAV as of 1-31-2026

2.00%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax- reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes.

If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

MCRSN-0226

MFS® Charter Income Trust

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders Source of distribution

Distribution period

January-2026

Distribution amount per share

$0.04484

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

 

Current

% Breakdown of

Total cumulative

% Breakdown of the total

 

distributions for the

cumulative distributions

 

distribution

current distribution

fiscal year to date

for the fiscal year to date

Net Investment Income

0.03901

87%

0.07809

87%

Net Realized ST Cap Gains

0.00000

0%

0.00000

0%

Net Realized LT Cap Gains

0.00000

0%

0.00000

0%

Return of Capital or

0.00583

13%

0.01167

13%

Other Capital Source

Total (per common share)

0.04484

100%

0.08976

100%

Average annual total return (in relation to NAV) for the five years ended 12-31-2025

2.78%

Annualized current distribution rate expressed as a percentage of month end NAV as of 12-31-2025

8.00%

Cumulative total return (in relation to NAV) for the fiscal year through 12-31-2025

0.42%

Cumulative fiscal year distributions as a percentage of NAV as of 12-31-2025

1.33%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax- reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes.

If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

MCRSN-0126

MFS® Charter Income Trust

P.O. Box 43078

Providence, RI 02940-3078

Notice to shareholders Source of distribution

Distribution period

December-2025

Distribution amount per share

$0.04492

The following table sets forth the estimated amounts of the current distribution and the cumulative distributions paid this fiscal year to date from the following sources: net investment income, net realized short-term capital gains, net realized long-term capital gains and return of capital or other capital source. The fund’s fiscal year begins each December 1st. All amounts are expressed per common share.

 

Current

% Breakdown of

Total cumulative

% Breakdown of the total

 

distributions for the

cumulative distributions

 

distribution

current distribution

fiscal year to date

for the fiscal year to date

Net Investment Income

0.04492

100%

0.04492

100%

Net Realized ST Cap Gains

0.00000

0%

0.00000

0%

Net Realized LT Cap Gains

0.00000

0%

0.00000

0%

Return of Capital or

0.00000

0%

0.00000

0%

Other Capital Source

Total (per common share)

0.04492

100%

0.04492

100%

Average annual total return (in relation to NAV) for the five years ended 11-30-2025

2.94%

Annualized current distribution rate expressed as a percentage of month end NAV as of 11-30-2025

7.99%

Cumulative total return (in relation to NAV) for the fiscal year through 11-30-2025

6.91%

Cumulative fiscal year distributions as a percentage of NAV as of 11-30-2025

0.67%

You should not draw any conclusions about the fund's investment performance from the amount of this distribution or from the terms of the fund's managed distribution plan.

The fund estimates that it has distributed more than its income and capital gains; therefore, a portion of your distribution may be a return of capital. A return of capital may occur, for example, when some or all of the money that you invested in the fund is paid back to you. A return of capital distribution does not necessarily reflect the fund's investment performance and should not be confused with "yield" or "income."

The amounts and sources of distributions reported in this notice are only estimates and are not being provided for tax- reporting purposes. The actual amounts and sources of the amounts for tax-reporting purposes will depend upon the fund's investment experience during the remainder of its fiscal year and may be subject to changes based on tax regulations. The fund will send you a Form 1099-DIV for the calendar year that will tell you how to report these distributions for federal income tax purposes.

If you have any questions regarding this information, please call our fund service department at 1-800-637-2304 any business day from 9 a.m. to 5 p.m. Eastern time.

MCRSN-1225